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Telecommunications Industry Association TR41.9.1-10-05-002L Document Cover Sheet Project Number PN-3-3602-RV4 Document Title TSB-31-D Draft document Source Industry Canada Contact Distribution Intended Purpose of Document (Select one) Matthew Mulvihill 3701 Carling Ave. Bldg. # 94 Ottawa, ON K4A 8S2 Phone: 613-990.5314 Fax: 613-990-4719 Email: [email protected] TR-41.9.1 For Incorporation Into TIA Publication For Information Other (describe) - The document to which this cover statement is attached is submitted to a Formulating Group or sub-element thereof of the Telecommunications Industry Association (TIA) in accordance with the provisions of Sections 6.4.1–6.4.6 inclusive of the TIA Engineering Manual dated October 2009, all of which provisions are hereby incorporated by reference. Abstract This is a working draft document to become TSB-31-D. v1.0 – 20050426 Telecommunications Industry Association TR41.9.1-10-05-002L Working Cover Page Telecommunications – Telephone Terminal Equipment Rationale and Measurement Guidelines for U.S. Network Protection Draft 0.4 April, 2010 Warning: This Document is a “work in progress” by TIA TR41.9 and as such it’s contents may change. Page 2 Telecommunications Industry Association TR41.9.1-10-05-002L FOREWORD This Document is a TIA Telecommunications Systems Bulletin (TSB), produced by Working Group TR-41.9.2 under subcommittee TR-41.9 of Engineering Committee TR-41, User Premises Telecommunications Requirements, under the sponsorship of the Telecommunications Industry Association [TIA]. Telecommunications Systems Bulletins are distinguished from TIA Standards in that TSBs contain a compilation of engineering data or information useful to the technical community and represent approaches to good engineering practices suggested by formulating group TR-41.9. This Bulletin is not intended to preclude or discourage other approaches which similarly represent good engineering practice, or which may be acceptable to, or have been accepted by, appropriate bodies such as the Federal Communications Commission [FCC]. Parties who wish other approaches to be considered for inclusion in future revisions of this Bulletin are encouraged to bring them to the attention of the formulating group. It is the intention of the formulating group to revise and update this Bulletin from time to time as may be occasioned by changes in technology, industry practice, government regulations, technical criteria, or other appropriate reasons. This Document outlines test methods for the technical criteria contained in the following documents: CFR, Title 47, FCC Part 68 TIA-968-B The changes to this Document from TSB-31-C are extensive due to the restructuring of TIA-968A and new technical criteria that have come into effect since TSB-31-C was published. This Document supersedes TIA-TSB-31-C and represents the consensus of the formulating group. Page 3 Telecommunications Industry Association TR41.9.1-10-05-002L TR-41.9 MEMBERS AND TSB-31-C CONTRIBUTORS People on this list either where a voting member of TR41.9 at the time this document was voted to publication or made contributions to the development of this document. Organization Represented Name of Representative ADTRAN, Inc Bell, Larry Atlinks Communications Pinkham, Clint Bourns Ltd. Maytum, Michael Broadcom Rahamim, Rafi Cisco Systems Lawler, Tim Hewlett-Packard Roleson, Scott Industry Canada Guevara, Efrain Industry Canada Mulvihill, Matthew Industry Canada Dawood, Hazim Intertek Testing Services Flom, Gary Littelfuse Inc. Havens, Philip Mitel Networks Slingerland, Greg Mobile Engineering Bipes, John Paradyne Inc. Walsh, Peter San-O-Industrial Lindquist, Carl Siemens Communication Inc. Tung, Tailey Sprint Chamney, Cliff Page 4 Telecommunications Industry Association TR41.9.1-10-05-002L Thomson Inc. Hunt, Roger Tyco Electronics Martin,Al Underwriters Labs Ivans, Randy Underwriters Labs Nguyen, Anh Verizon Bishop, Trone Vtech Engineering Whitesell, Steve Page 5 Telecommunications Industry Association TR41.9.1-10-05-002L CONTENTS FOREWORD i TR-41.9 MEMBERS AND TSB-31-C CONTRIBUTORS ii CONTENTS iii LIST OF FIGURES vii 1 INTRODUCTION 12 2 SCOPE 13 3 REFERENCES 14 4 DEFINITIONS, ACRONYMS AND ABBREVIATIONS 15 5 GENERAL INFORMATION 23 5.1 Safety Warning About The Procedures In This Document 23 5.2 General Document Structure 23 5.3 Simulator Circuit Theory 23 5.4 Test Conditions 24 5.5 Suggested Equipment List (SEL) 24 5.6 Test Requirements Matrix 31 6 ENVIRONMENTAL SIMULATION ANSI/TIA-968-A, 4.2 32 6.1 Sequencing of Environmental Simulations 32 6.2 Mechanical Shock ANSI/TIA-968-A, 4.2.1 37 6.3 Telephone Line Surge - Type A, Metallic. ANSI/TIA-968-A, 4.2.2.1 38 6.4 Telephone Line Surge - Type A, Longitudinal. ANSI/TIA-968-A, 4.2.2.2 40 6.5 Telephone Line Surge - Type B, Metallic. ANSI/TIA-968-A, 4.2.3.1 42 6.6 Telephone Line Surge - Type B, Longitudinal. ANSI/TIA-968-A, 4.2.3.2 46 6.7 Power Line Surge ANSI/TIA-968-A, 4.2.4 49 7 LEAKAGE CURRENT LIMITATIONS (ANALOG AND DIGITAL) ANSI/TIA-968-A, 4.3 51 8 HAZARDOUS VOLTAGE LIMITATIONS ANSI/TIA-968-A, 4.4 56 8.1 Hazardous Voltage Limitations, General ANSI/TIA-968-A, 4.4.1 56 8.2 Hazardous Voltage Limitations, E&M ANSI/TIA-968-A, 4.4.1.1, 4.4.1.2, 4.4.1.3 58 Page 6 Telecommunications Industry Association TR41.9.1-10-05-002L 8.3 Hazardous Voltage Limitations, OPS ANSI/TIA-968-A, 4.4.1.4 63 8.4 Hazardous Voltage Limitations, DID ANSI/TIA-968-A, 4.4.1.5 66 8.5 Hazardous Voltage Limitations, LADC ANSI/TIA-968-A, 4.4.1.6 68 8.6 Ringdown Voiceband Private Line and Metallic Channel Interface ANSI/TIA-968-A, 4.4.1.7 71 8.7 Physical Separation of Leads ANSI/TIA-968-A, 4.4.2 74 8.8 Ringing Sources ANSI/TIA-968-A, 4.4.4 76 8.9 Intentional Operational Paths to Ground ANSI/TIA-968-A, 4.4.5.1 82 8.10 Intentional Protective Paths to Ground ANSI/TIA-968-A, 4.4.5.2 85 9 SIGNAL POWER LIMITATIONS ANSI/TIA-968-A, 4.5 88 9.1 Voiceband Signal Power – Not Network Control signals ANSI/TIA-968-A, 4.5.2.1 88 9.2 Voiceband Signal Power - Network Control Signals ANSI/TIA-968-A, 4.5.2.2 96 9.3 Through-Transmission Equipment – DC Conditions for On-Premises ANSI/TIA-968-A, 4.5.2.3.1 102 9.4 Through-Transmission Equipment – Data ANSI/TIA-968-A 4.5.2.3.2 105 9.5 Voiceband Signal Power - Data ANSI/TIA-968-A, 4.5.2.4 107 9.6 Through-Transmission – Port to Port Amplification ANSI/TIA-968-A, 4.5.2.5.1 111 9.7 Through-Transmission - SF Cutoff ANSI/TIA-968-A, 4.5.2.5.1(7) 117 9.8 Through-Transmission - SF/Guard Bands ANSI/TIA-968-A, 4.5.2.5.2 120 9.9 Return Loss, Tie Trunk - Two Wire ANSI/TIA-968-A, 4.5.2.6.1 126 9.10 Return Loss, Tie Trunk - Four Wire ANSI/TIA-968-A, 4.5.2.6.2 129 9.11 Transducer Loss, Tie Trunk - Four Wire ANSI/TIA-968-A, 4.5.2.6.3 133 9.12 DC Conditions, OPS ANSI/TIA-968-A, 4.5.2.7 137 9.13 Signal Power 3995 Hz - 4005 Hz – Not Network Control Signals ANSI/TIA-968-A, 4.5.3.1 140 9.14 Through Transmission – 3995-4005 Hz vs 600-4000 Hz ANSI/TIA-968-A, 4.5.3.2 144 9.15 Non-LADC Longitudinal Voltage – 0.1 - 4 kHz ANSI/TIA-968-A, 4.5.4 148 9.16 Non-LADC Metallic Voltage - 4 kHz to 30 MHz ANSI/TIA-968-A, 4.5.5.1 153 9.17 Non-LADC Longitudinal Voltage - 4 kHz to 6 MHz ANSI/TIA-968-A, 4.5.5.2 162 9.18 Metallic Voltage 0.01 kHz to 30 MHz, LADC ANSI/TIA-968-A, 4.5.6.1, 4.5.6.2 172 Page 7 Telecommunications Industry Association TR41.9.1-10-05-002L 9.19 Longitudinal Voltage 0.01 kHz to 6 MHz, LADC ANSI/TIA-968-A, 4.5.6.3 184 9.20 Pulse Repetition Rate, Subrate/PSDS, ANSI/TIA-968-A, 4.5.8.1.1 and 4.5.8.3.1 195 9.21 Encoded Analog Content ANSI/TIA-968-A 4.5.8.1.2, 4.5.8.4, 4.5.8.2.5, 4.5.10 198 9.22 Equivalent PSD For Maximum Output, Subrate – ANSI/TIA-968-A, 4.5.8.1.3 201 9.23 Average Power, Subrate, Non-Secondary Channel Rates, Secondary Channel Rates ANSI/TIA-968-A, 4.5.8.1.4 and 4.5.8.1.5 204 9.24 Pulse Template, Subrate/PSDS ANSI/TIA-968-A, 4.5.8.1.6 and 4.5.8.3.2 207 9.25 Average Power, Subrate ANSI/TIA-968-A, 4.5.8.1.7 210 9.26 Pulse Repetition Rate, 1.544 Mb/s ANSI/TIA-968-A, 4.5.8.2.1 213 9.27 Pulse Template, 1.544 Mb/s ANSI/TIA-968-A, 4.5.8.2.2, 4.5.8.2.3 215 9.28 Output Power, 1.544 Mb/s ANSI/TIA-968-A, 4.5.8.2.4 218 9.29 Unequipped Sub-rate Channels ANSI/TIA-968-A, 4.5.8.2.6 222 9.30 Conditioning ADSL EUT to Transmit Continuously 224 9.31 Total Average Power, ADSL Terminal Equipment ANSI/TIA-968-A-3, 4.5.9.1.1 226 1.1 Power Spectral Density, ADSL Terminal Equipment ANSI/TIA-968-A-3, 4.5.9.1.2, 4.5.9.1.3 228 9.31 Longitudinal Output Voltage, ADSL Terminal Equipment ANSI/TIA-968-A-3, 4.5.9.1.4 240 9.32 Voiceband Signal Power - Non-approved external signal sources ANSI/TIA-968-A-3, 4.5.2.2 243 10 TRANSVERSE BALANCE LIMITATIONS ANSI/TIA-968-A, 4.6 248 10.1 Transverse Balance, Analog ANSI/TIA-968-A, 4.6.2 248 10.2 Transverse Balance, Digital ANSI/TIA-968-A, 4.6.3, 4.6.4 254 11 ON HOOK IMPEDANCE LIMITATIONS ANSI/TIA-968-A, 4.7 259 11.1 DC Resistance ANSI/TIA-968-A, 4.7.2.1, 4.7.2.2 259 11.2 DC Current During Ringing, Loop Start and Ground Start ANSI/TIA-968-A, 4.7.2.3, 4.7.3.1 264 11.3 AC Impedance During Ringing, Loop Start and Ground Start (Metallic and Longitudinal) ANSI/TIA-968-A, 4.7.2.4, 4.7.2.5, 4.7.3.2 268 11.4 REN Calculation ANSI/TIA-968-A, 4.7.4, 4.7.5 273 11.5 OPS Ring Trip, PBX with DID ANSI/TIA-968-A, 4.7.6 275 11.6 Transitioning to the Off-Hook State and Make-busy ANSI/TIA-968-A, 4.7.8 278 Page 8 Telecommunications Industry Association TR41.9.1-10-05-002L 11.7 Manual Programming of Repertory Numbers, ANSI/TIA-968-A, 4.7.8.1 280 11.8 Automatic Stuttered Dial Tone Detection ANSI/TIA-968-A, 4.7.8.2 282 12 BILLING PROTECTION ANSI/TIA-968-A, 4.8 285 12.1 Call Duration for Data Equipment, Protective Circuitry ANSI/TIA-968-A, 4.8.1.1 285 12.2 Call Duration for Data Applications, Terminal Equipment ANSI/TIA-968-A, 4.8.1.2 289 12.3 On-hook Signal Power, Analog ANSI/TIA-968-A, 4.8.2 293 12.4 Off-Hook Loop Current ANSI/TIA-968-A, 4.8.3 297 12.5 Signaling Interference, Analog ANSI/TIA-968-A, 4.8.4.1 303 12.6 Signaling Interference, Digital ANSI/TIA-968-A, 4.8.4.2 307 12.7 On-Hook Signal Power, Subrate and 1.544 Mb/s ANSI/TIA-968-A, 4.8.5 311 12.8 Signaling Duration, 1.544 Mb/s ANSI/TIA-968-A, 4.8.6 314 12.9 Operating Requirements for DID ANSI/TIA-968-A, 4.8.7 317 13 Connectors 321 13.1 Gold Contact Interface 321 13.2 Non-gold Contact Interface 321 14 OTHER TYPES OF DSL TERMINAL EQUIPMENT 322 14.1 Metallic Signals TIA-968-A-3, 4.5.9.2.1 and TIA-968-A-4, 4.5.9.2.4 322 14.2 Longitudinal Output Voltage Limits TIA-968-A-3 and TIA-968-A-4, 4.5.9.2.3 328 14.3 Transverse Balance TIA-968-A-3, 4.6.5 331 15 HEARING AID COMPATIBILITY 58 15.1 Hearing Aid Compatibility – Magnetic Field Intensity 47 CFR, 68.316 58 15.2 Hearing Aid Compatibility - Volume Control 47 CFR, 68.317 66 16 MISCELLANEOUS 75 16.1 Limitations on Automatic Redialing 47 CFR, 68.318(b) 75 16.2 Line Seizure by Automatic Telephone Dialing Systems - 47 CFR, 68.318(c) 80 16.3 Telephone Facsimile Machines: Identification of the Sender of Messages (FAX branding) – 47 CFR, 68.318(d) 82 16.4 Equal Access to Common Carriers - 47 CFR, 68.318(e) 85 APPENDIX A, TEMPLATES for DIGITAL PULSES 87 Page 9 Telecommunications Industry Association TR41.9.1-10-05-002L B.A.1 Templates for Subrate and PSDS Digital Pulses 87 B.1.2 Templates for ISDN PRA and 1.544 Mb/s Digital Pulses 102 APPENDIX B, EXAMPLE CALCULATIONS OF WAVEFORM ENERGY LEVELS 105 Appendix C, Alternate Transverse Balance, Digital EUT 107 B.A.2 Background 107 B.A.3 Purpose 108 B.A.4 Equipment 108 B.A.5 Equipment States Subject To Test 108 B.A.6 Procedure 108 Appendix D, Test Procedures for Passive Splitter Filters and Passive Micro-Filters 111 D.1 Background 111 D.2 Example of Splitter Filter 111 D.3 Example of Micro-Filter 112 D.4 Applicable ANSI/TIA-968-A Technical Criteria from TSB-31-C Test Matrix 112 D.5 Test Methods for Splitter Filters 115 D.6 Test Methods for Micro-Filters 117 Page 10 Telecommunications Industry Association TR41.9.1-10-05-002L LIST OF FIGURES Figure 6.1-1 Environmental Flowchart 34 Figure 7-1. Leakage Current 55 Figure 8.2-1 E or M-Lead Contact Protection 62 Figure 8.8-1 Ringing Sources, Two-Wire 79 Figure 8.8-2 Ringing Sources, Four-Wire 80 Figure 8.8-3 Ringing Protection 81 Figure 8.9-1 Intentional Operational Paths to ground 84 Figure 8.10-1 Intentional Protective Paths to Ground 87 Figure 9.1-1. Voiceband Signal Power, Two-Wire 93 Figure 9.1-2. Voiceband Signal Power, Four-Wire 94 Figure 9.1-3. Voiceband Signal Power, E&M Tie 95 Figure 9.2-1. Network Control Signal Power, Two-Wire 100 Figure 9.2-2. Network Control Signal Power, Four-Wire 101 Figure 9.3-1. DC Conditions for Through Transmission 104 Figure 9.5-1. Voiceband Signal Power, Data, TE 110 Figure 9.6-1 Through Transmission, Analog 114 Figure 9.6-2. Through Transmission, Digital 115 Figure 9.6-3. Digital EUT Arrangement for Figure 9.6-2 116 Figure 9.7-1. Single Frequency Cut-off 119 Figure 9.8-1. Through Transmission - SF Guard Bands, Analog 123 Figure 9.8-2. Through Transmission - SF Guard Bands, Digital 124 Figure 9.8-3. Digital EUT Arrangement for Figure 9.8-2 125 Figure 9.9-1. Return Loss, Two-Wire 128 Figure 9.10-1. Return Loss, Four-Wire, T&R 131 Figure 9.10-2. Return Loss, Four-Wire, T1&R1 132 Figure 9.11-1. Transducer Loss, Forward 135 Figure 9.11-2 Transducer Loss, Reverse 136 Page 11 Telecommunications Industry Association TR41.9.1-10-05-002L Figure 9.12-1. OPS DC Conditions 139 Figure 9.13-1. Signal Power, 3995-4005 Hz, Internal Sources 143 Figure 9.14-1 Signal Power, 3995-4005 Hz vs 600-4000 Hz, Through Transmission 147 Figure 9.15-1. Voiceband Longitudinal Voltage 152 Figure 9.16-1. Non-LADC Metallic 4 kHz to 30 MHz 160 Figure 9.16-2. Non-LADC Metallic 270 kHz to 30 MHz 161 Figure 9.17-1. Non-LADC Longitudinal 4 kHz to 6 MHz 170 Figure 9.17-2. Non-LADC Longitudinal 270 kHz to 6 MHz 171 Figure 9.18-1. LADC Metallic 10 Hz to 4 kHz, T&R 178 Figure 9.18-2. LADC Metallic 10 Hz to 4 kHz, T1 & R1 179 Figure 9.18-3. LADC Metallic 700 Hz to 270 kHz, T&R 180 Figure 9.18-4. LADC Metallic 700 Hz to 270 kHz, T1&R1 181 Figure 9.18-5. LADC Metallic 270 kHz to 30 Mhz, T&R 182 Figure 9.18-6. LADC Metallic 270 kHz to 30 MHz, T1&R1 183 Figure 9.19-1. LADC Longitudinal 10 Hz - 4 kHz, T&R 189 Figure 9.19-2. LADC Longitudinal 10 Hz to 4 kHz, T1 & R1 190 Figure 9.19-3. LADC Longitudinal 4 kHz to 270 kHz, T & R 191 Figure 9.19-4. LADC Longitudinal 4 kHz to 270 kHz, T1 & R1 192 Figure 9.19-5. LADC Longitudinal 270 kHz to 6 MHz, T & R 193 Figure 9.19-6. LADC Longitudinal 270 kHz to 6 Mhz, T1 & R1 194 Figure 9.20-1. Subrate, Pulse Repetition Rate 197 Figure 9.21-1. Encoded Analog Content 200 Figure 9.22-1. Subrate Signal Power 203 Figure 9.23-1. Subrate Signal Power 206 Figure 9.24-1. Subrate and PSDS, Pulse Template. 209 Figure 9.25-1. Subrate, Average Power 212 Figure 9.26-1. 1.544 megabits per second (Mb/s), Pulse Repetition Rate 214 Figure 9.27-1. 1.544 Mb/s, Pulse Template connection diagram 217 Figure 9.28-1. 1.544 megabits per second (Mb/s), Output Power 221 Page 12 Telecommunications Industry Association TR41.9.1-10-05-002L Figure 9.31-1. Average Signal Power 227 Figure 9.32-1. PSD Connection Diagram For Segments 1 & 2 234 Figure 9.32-2. Sample PSD Plot For Segment 1 235 Figure 9.32-3. Sample PSD Plot For Segment 2 236 Figure 9.32-4. PSD Connection Diagram For Segment 3 237 Figure 9.32-5. Sample PSD Plot For Segment 3 238 Figure 9.32-6. PSD Connection Diagram For Segment 4 239 Figure 9.32-7. Sample PSD Plot For Segment 4 239 Figure 9.33-1. LOV Test Fixture & Connection Diagram 242 Figure 9.33-2. Sample LOV Plot 242 Figure 9.36-1. Voiceband Signal Power - Non-approved external signal sources 247 Figure 10.1-1 Transverse Balance, Analog 253 Figure 10.2-1 Transverse Balance, Digital 258 Figure 11.1-1. DC Resistance, T-R 262 Figure 11.1-2. DC Resistance, T-GND & R-GND 263 Figure 11.2-1. DC Current During Ringing 267 Figure 11.3-1. AC Impedance, T-R 271 Figure 11.3-2. AC Impedance, T-GND & R-GND 272 Figure 11.5-1. OPS Ring Trip 277 Figure 11.7-1. Manual Programming of Repertory Dialing Numbers 281 Figure 11.8-1. Manual Programming of Repertory Dialing Numbers 284 Figure 12.1-1. Call Duration, PC, Transmit 287 Figure 12.1-2. Call Duration, PC, Receive 288 Figure 12.2-1. Call Duration, EUT, Transmit 291 Figure 12.2-2. Call Duration, EUT, Receive 292 Figure 12.3-1. On-hook Signal Power, TE 295 Figure 12.3-2. On-hook Signal Power, PC 296 Figure 12.4-1. Loop Current, 200 ohm Method 301 Figure 12.4-2. Loop Current, 25% Method 302 Page 13 Telecommunications Industry Association TR41.9.1-10-05-002L Figure 12.5-1. Signaling Interference 306 Figure 12.6-1. 1.544 Mb/s, Signaling Interference 310 Figure 12.7-1. Subrate and 1.544 Mb/s, On-hook Level 313 Figure 12.8-1. 1.544 megabits per second (Mb/s), Signaling Duration 316 Figure 12.9.5.1-1. Analog Direct Inward Dialing 319 Figure 12.9.5.2-1 1.544 megabits per second (Mb/s) Direct Inward Dialing 320 Figure 14.1-1 Test Configuration to Establish Data Mode 327 Figure 14.1-2 Test Configuration to Measure PSD and Total Power 327 Figure 14.2-1 LOV TEST FIXTURE & CONNECTION DIAGRAM 330 Figure 15.1-1 Setup for testing 47 CFR, 68.316 HAC for Analog Telephone 62 Figure 15.1-2 Setup for testing 47 CFR, 68.316 HAC for ISDN Telephone 63 Figure 15.1-3 Setup for testing 47 CFR, 68.316 HAC for Proprietary & Special use Telephone 64 Figure 15.1-4 Setup for testing 47 CFR, 68.316 HAC for IP-based Telephone 65 Figure 15.2-1 Setup for testing 47 CFR, 68.317 HAC volume control for Analog Telephone 71 Figure 15.2-2 Setup for testing 47 CFR, 68.317 HAC volume control for ISDN Telephone 72 Figure 15.2-3 Setup for testing 47 CFR, 68.317 HAC volume control for Proprietary & Special use Telephone 73 Figure 15.2-4 Setup for testing 47 CFR, 68.317 HAC volume control for IP-based Telephone 74 Figure 16.1 2 Limitations on automatic redialing 79 Figure A1-1. Subrate, Pulse Template, 2.4 kilobits per second (kb/s) 88 Figure A1-2. Subrate, Pulse Template, 3.2 kilobits per second (kb/s) 89 Figure A1-3. Subrate, Pulse Template, 4.8 kilobits per second (kb/s) 90 Figure A1-4. Subrate, Pulse Template, 6.4 kilobits per second (kb/s) 91 Figure A1-5. Subrate, Pulse Template, 9.6 kilobits per second (kb/s) 92 Figure A1-6. Subrate, Pulse Template, 12.8 kilobits per second (kb/s) 93 Figure A1-7. Subrate, Pulse Template, 19.2 kilobits per second (kb/s) 94 Figure A1-8. Subrate, Pulse Template, 25.6 kilobits per second (kb/s) 95 Figure A1-9. Subrate, Pulse Template, 38.4 kilobits per second (kb/s) 96 Figure A1-10. Subrate, Pulse Template, 51.2 kilobits per second (kb/s) 97 Figure A1-11. Subrate, Pulse Template, 56.0 kilobits per second (kb/s) 98 Page 14 Telecommunications Industry Association TR41.9.1-10-05-002L Figure A1-12. Subrate, Pulse Template, 72.0 kilobits per second (kb/s) 99 Figure A1-13. PSDS Type II Pulse Template, 144 kilobits per second (kb/s) 100 Figure A1-14. PSDS Type Iii Pulse Template, 160 kilobits per second (kb/s) 101 Figure A2-1. 1.544 megabits per second (Mbps), Pulse Template, Option B 103 Figure A2-2. 1.544 megabits per second (Mbps), Pulse Template, Option C 104 Figure B1-1. Calculation of Energy Levels 106 Figure C-1: Test Fixture To Measure Transverse Balance Using A Ratio Of Currents 110 Page 15 Telecommunications Industry Association TR41.9.1-10-05-002L Page 16 Telecommunications Industry Association TR41.9.1-10-05-002L INTRODUCTION 47 CFR Part 68 of the Federal Communications Commission (FCC) rules and regulations (Clause 3, ref 9) contains and references the minimum technical standards that terminal equipment must meet in order to be connected to the telephone network. 47 CFR Part 68 references technical criteria adopted by the Administrative Council for Terminal Attachments (ACTA) which provides uniform standards for the protection of the telephone network from harm caused by the connection of terminal equipment. 47 CFR Part 68 defines harm as: electrical hazards to the personnel of providers of wireline telecommunications; damage to the equipment of providers of wireline telecommunications; malfunction of the billing equipment of providers of wireline telecommunications; and, degradation of service to persons other than the user of the subject terminal equipment and his calling or called party. In addition, 47 CFR Part 68 contains terminal equipment requirements that address specific consumer protection issues. At the time of publication these were: compatibility with magnetically coupled hearing aids; receive volume control on devices with a handset or headset; identification of the sender of the message by telephone facsimile machines; access to common carriers; automatic dialing and redialing capability; and, line seizure by automatic telephone dialing systems. Terminal equipment may not be connected to the telephone network unless it has either been certified by a Telecommunication Certification Body (TCB) or the responsible party has followed all of the procedures in 47 CFR Part 68 for a Supplier’s Declaration of Conformity (SDoC). Both of these approval processes require terminal equipment to be tested for compliance with the technical criteria in 47 CFR Part 68 and the technical criteria adopted by the ACTA. This Document recommends test procedures, test equipment, and guidelines for determining compliance with the technical criteria in 47 CFR Part 68 and the technical criteria adopted by the ACTA. Page 17 Telecommunications Industry Association TR41.9.1-10-05-002L The ACTA can be contacted via the Internet at www.part68.org. Page 18 Telecommunications Industry Association TR41.9.1-10-05-002L Page 19 Telecommunications Industry Association TR41.9.1-10-05-002L SCOPE This Document recommends test procedures, test equipment, and guidelines for determining compliance with the technical requirements of 47 CFR Part 68 and the technical criteria adopted by the ACTA. At the time of publication, this Telecommunications Systems Bulletin [TSB] addressed requirements in the following Documents: CFR, Title 47, FCC Part 68 TIA-968-B This Document proposes at least one measurement procedure for each technical requirement and, in some cases, an alternative measurement procedure. However, in most cases, these proposed procedures are not exclusive. Other measurement procedures and test equipment may provide equivalent results. In the event of conflict between any of the standards outlined above and this Document, the standard takes precedence. The test procedures do not cover the administrative or other equipment authorization procedures that may be required to obtain product approval. It is recommended that you refer to the administrative requirements outlined by the ACTA. TIA also has TIA-TSB-129-A that summarizes these administrative requirements. Each test procedure is cross-referenced to the appropriate subclause of the applicable requirements document. subclause 5.6 provides a test requirement matrix that indicates the applicable requirement(s) and test guideline(s) for each specific type of network interface. Some of the tests or procedures specified in this Document may involve the presence of hazardous voltages and currents or other potential dangers. Some of these hazards have been identified, and appropriate warnings have been included in the text specifying such tests or procedures. Appropriate safety precautions are always recommended when performing any laboratory test or procedure. Page 20 Telecommunications Industry Association TR41.9.1-10-05-002L Page 21 Telecommunications Industry Association TR41.9.1-10-05-002L REFERENCES The following documents contain provisions that may be useful in carrying out the recommended test procedures and guidelines for determining compliance provided in this document. At the time of publication, the editions indicated were valid. All documents are subject to revision, and parties to agreements based on this Document are encouraged to investigate the possibility of applying the most recent editions of the documents published by them. 1. ANSI T1.401-2000, Network to Customer Installation Interfaces – Analog Voice grade Switched Access Lines Using Loop-Start and Ground-Start Signaling 2. ANSI/TIA-470-A, Telephone Instruments with Loop Signaling 3. ANSI/TIA-470.110-C, Telecommunications – Telephone Terminal Equipment – Handset Acoustic Performance Requirements for Analog Terminals 4. ANSI/TIA-579, Acoustic-to-Digital and Digital-to-Acoustic Transmission Requirements for ISDN Terminals. 5. ANSI/TIAEIA-810-A -2000, Telecommunications – Telephone Terminal Equipment – Transmission Requirements for Narrowband Voice Over IP and Voice Over PCM Digital Wireline Telephones. 6. ANSI/TIA-968-A (2002), Telecommunications – Telephone Terminal Equipment Technical Requirements for Connection of Terminal Equipment to the Telephone Network 7. ANSI/TIA-968-A-1 (2003), Telecommunications – Telephone Terminal Equipment Technical Requirements for Connection of Terminal Equipment to the Telephone Network 8. ANSI/TIA-968-A-2 (2004), Telecommunications – Telephone Terminal Equipment Technical Requirements for Connection of Terminal Equipment to the Telephone Network 9. ANSI/TIA-968-A-3 (2005), Telecommunications – Telephone Terminal Equipment Technical Requirements for Connection of Terminal Equipment to the Telephone Network 10. ANSI/TIA-968-A-4 (2006), Telecommunications – Telephone Terminal Equipment Technical Requirements for Connection of Terminal Equipment to the Telephone Network Page 22 Telecommunications Industry Association TR41.9.1-10-05-002L 11. ANSI S1.15-1997 (R2001), Measurement Microphones – Part 1: Specification for Laboratory Standard Microphones 12. ANSI S3.7-1995 (R2003), Method for Coupler Calibration of Earphones. 13. CS-03, (Issue 9, November 2004, Industry Canada), Compliance Specification for Terminal Equipment, Terminal Systems, Network Protection Devices, Connection Arrangements and Hearing Aids Compatibility. 14. FCC Part 2, Code of Federal Regulations (CFR), Title 47, Part 2, Frequency Allocations and Radio Treaty Matters; General Rules and Regulations. 15. FCC Part 68, Code of Federal Regulations (CFR), Title 47, Part 68, Connection of Terminal Equipment to the Telephone Network. 16. IEEE 269-2002, IEEE Standard Methods for Measuring Transmission Performance of Analog and Digital Telephone Sets, Handsets, and Headsets. 17. IEEE 661-1979 (R1998), IEEE Standard Method for Determining Objective Loudness Ratings of Telephone Connections. 18. IEEE 1027 (1996), Method for Measuring of the Magnetic Field Intensity In The Vicinity of a Telephone Receiver. 19. TIA-504 (1995)(R2003), Telecommunications-Telephone Terminal Equipment-Magnetic Field and Acoustic Gain Requirements for Headset Telephones Intended for Use by the Hard of Hearing. 20. ITU-T Recommendation K.21 (2003-07) Resistibility of telecommunication equipment installed in customer premises to overvoltages and overcurrents 21. ITU-T P.57 (11/2005), Series P: Telephone Transmission Quality, Telephone Installations, Local Line Networks – Objective Measuring Apparatus – Artificial Ears. 22. ITU-T P.79 (09/1999), Series P: Telephone Transmission Quality, Telephone Installations, Local Line Networks – Measurements Related to Speech loudness – Calculation of Loudness Ratings for Telephone Sets.TIA/TSB-129-A (2002), Telecommunications – Telephone Terminal Equipment - U.S. Network Connections Regulatory Approval Guide 23. TIA/TSB-168-A (2003), Telecommunications – Telephone Terminal Equipment – Labeling Requirements 24. TIA-470.000-C (2004), Telecommunications Terminal Equipment Overview of Performance Standards for Analog Telephones. DEFINITIONS, ACRONYMS AND ABBREVIATIONS Page 23 Telecommunications Industry Association TR41.9.1-10-05-002L For the purposes of this Document, the following definitions apply ADSL: Asynchronous Digital Subscriber Loop Cadenced Ringing: The process of alerting the called party with the application of a ringing signal which is cycled on and off. Note: Typical CO ringing consists of 2-second intervals of 20 Hz energy applied between tip and ring, followed by a 4-second quiet interval. This sequence is repeated until the called party answers or the call is abandoned. Capture Level: Equipment with AGC (Automatic Gain Control) signal power limiting has virtually no output signal power for input levels below a certain value. At some input signal power, the output level will become significant (usually corresponding to the expected output level for service application). The input level at which this occurs is defined as the “capture level”. Central office implemented telephone: A telephone executing coin acceptance requiring coin service signaling from the central office on a loop start access line. Note: For 47 CFR Part 68 and ANSI/TIA-968-A testing purposes, central office implemented telephones are treated somewhat differently than most loop start devices due to the use of coin service signaling. The differences are identified by notes and explanatory text throughout this Document. See also the definition for coin-implemented telephone. CO: Telephone Central Office. CODEC: Coder/Decoder (analog or digital) Coin-implemented telephone: A telephone containing all circuitry required to execute coin acceptance and related functions within the instrument itself and not requiring coin service signaling from the central office. Note: For 47 CFR Part 68 and ANSI/TIA-968-A testing purposes, coin-implemented telephones are treated like any other loop start device. See also the definition for central office implemented telephone. Common Mode: See Longitudinal Mode. CPE [Customer Premises Equipment]: Equipment which is located on the customer's side of the network interface. DC Signal: A DC voltage or current. Page 24 Telecommunications Industry Association TR41.9.1-10-05-002L DC Signaling: The transmission of information using changes in DC signals. Note: Pulse dialing is an example of DC signaling used for the purpose of network addressing. dBm: Power level in decibels with reference to a power of 0.001 W (e.g., 0 dBm is a power level of 1 mW). dBV: Voltage in decibels with reference to a voltage level of 1 V (e.g. 0 dBV is a voltage level of 1 V). DID [Direct Inward Dialing]: A feature that permits incoming PSTN calls to be routed directly to a PBX station upon receipt of addressing information. Differential Mode: See Metallic Mode. DTMF [Dual Tone Multi-Frequency]: A means of network signaling that uses a simultaneous combination of two specified voiceband tones to represent a digit (i.e. twelve different combinations of seven tones provide digits 0 through 9, *, and #). Encoded Analog Content: The digital representation of analog signals encoded in a digital bitstream. See also Section 13.10.1. EUT: Equipment Under Test. FIC: Facility Interface Code A code which identifies the type of network facility necessary for a connection. Note: These codes are listed in TSB-129-A. Ground Start: A method of signaling whereby one of the network connections is grounded by equipment (CO or CPE) originating a demand for service. Intentional Conducting Path to Ground: Any electrical path which, by design, has components which are intended to allow currents to flow to ground. ISDN: Integrated Services Digital Network ISDN BRA: Basic Rate Access Page 25 Telecommunications Industry Association TR41.9.1-10-05-002L ISDN Basic Rate Interface: A two-wire interface between the terminal equipment and ISDN BRA ISDN PRA: Primary Rate Access ISDN Primary Rate Interface: A four-wire interface between the terminal equipment and 1.544 Mbps PRA. Isolated Pulse: A pulse whose waveform is unaffected by leading or trailing pulses. KTS: Key Telephone System LADC [Local Area Data Channel]: A channel which allows wider than voiceband frequency transmission over network private line metallic facilities. LAN: Local Area Network Live Voice: Actual human speech as opposed to recorded or synthesized speech. Longitudinal Mode: That portion of a signal, which is identical in amplitude and phase, on both leads of a transmission pair with respect to ground. Loop Start: A method of signaling using the completion of a DC current path (loop). Metallic Mode: That portion of a signal, which is identical in amplitude and opposite in phase, on both leads of a transmission pair with respect to ground. Off-Hook: A term used to denote the active state of telephone terminal equipment. On-Hook: A term used to denote the inactive state of telephone terminal equipment. Page 26 Telecommunications Industry Association TR41.9.1-10-05-002L OPS [Off Premises Station]: CPE intended to be located on a premises not contiguous with the premises of its associated PBX, or KTS, and where the two units are connected via telephone network facilities. Overload Point: For signal power limiting circuits incorporating automatic gain control method, the “overload point” is the value of the input signal that is 15 dB greater than the capture level. For signal power limiting circuits incorporating peak limiting method, the “overload point” is defined as the input level at which the equipment’s through gain decreases by 0.4 dB from its nominal constant gain. PBX: Private Branch Exchange PC: Protective Circuitry. Primary Protector: Devices, installed by the telephone companies, on circuits which are exposed to voltages induced on cables by lightning strikes. Note: Such devices limit the magnitude of the voltage presented to the customer premises wire and equipment. PSD: Power Spectral Density PSDS Type II Analog Mode Loop Simulator Circuit: A circuit simulating the network side of the two-wire telephone connection that is used for testing terminal equipment to be connected to the PSDS Type II loops. PSTN: Public Switched Telephone Network. Public Switched Digital Service Type I (PSDS Type I): This service functions only in a digital mode. It employs a transmission rate of 56 Kbps on both the transmit and receive pairs to provide a four-wire full duplex digital channel. Public Switched Digital Service Type II (PSDS Type II): This service functions in two modes, analog and digital. Analog signaling procedures are used to perform supervisory and address signaling over the network. Page 27 Telecommunications Industry Association TR41.9.1-10-05-002L Note: After an end-to-end connection is established, the Switched Circuit Data Service Unit (SCDSU) is switched to the digital mode. Public Switched Digital Service Type III (PSDS Type III): This service functions only in a digital mode. It uses a time compression multiplexing (TCM) rate of 160 Kbps, over one pair to provide a full duplex 64 Kbps user channel. Page 28 Telecommunications Industry Association TR41.9.1-10-05-002L REN [Ringer Equivalence Number]: A normalized measure of the on-hook electrical impedance load presented to the PSTN by the CPE. Note: REN is used to determine the quantity of devices that may be connected to a single telephone line and still have all those devices ring when that telephone number is called. In most areas, the sum of the RENs of all devices connected to one line should not exceed five (5.0). Reverse Battery Interface: An interface, used with DID, where the battery feed is provided by the CPE instead of the CO and where the CPE uses a signaling method of polarity reversal to indicate call status towards the CO. SF [Single Frequency]: SF is a method of network signaling that uses in-band signals. Note: The SF signaling band is from 2450 Hz to 2750 Hz. The SF guard band is from 800 Hz to 2450 Hz. Subrate Digital Service: A digital service providing full-time, simultaneous, two-way transmission of digital signals at speeds as specified in ANSI/TIA-968-A, subclause 4.5.8. Switched Circuit Data Service Unit (SCDSU): A CPE device, with PSDS functionality, located between the network Interface and the data terminal equipment. Note: SCDSU is also sometimes referred to as Network Channel Terminating Equipment). Switchhook: A term that refers to that component of the telephone terminal equipment controlling its operating states (See also On-Hook and Off-Hook). TE: Terminal Equipment. Test Equipment: Equipment connected at the customer’s premises that is used on the customer’s side of the network interfaces to measure characteristics of the telephone network; or to detect and isolate a communications fault between a terminal equipment entity and the telephone network. Page 29 Telecommunications Industry Association TR41.9.1-10-05-002L Tie Trunk: A private line between two customer premises switching systems. WAN: Wide Area Network White Noise: Noise, either random or impulsive type, that has a flat frequency spectrum over the frequency range of interest. Zero Level Decoder: A decoder that yields an analog level of 0 dBm at its output when the input is the digital mW signal (digital equivalent of a 0 dBm, 1000 Hz sine wave). Zero Level Encoder: An encoder that yields the digital mW signal (digital equivalent of a 0 dBm, 1000 Hz sine wave) at its output when the input is an analog level of 0 dBm. Page 30 Telecommunications Industry Association TR41.9.1-10-05-002L GENERAL INFORMATION 1.1 Safety Warning About The Procedures In This Document Some of the tests or procedures specified in this Document may involve the presence of hazardous voltages and currents or other potential dangers. Some of these hazards have been identified, and appropriate warnings have been included in the text specifying such tests or procedures. Appropriate safety precautions are always recommended when performing any laboratory test or procedure. 1.2 General Document Structure Each test procedure is cross-referenced to the appropriate subclause of the applicable requirements document. subclause 5.6 provides a test requirement matrix that indicates the applicable requirement(s) and test guideline(s) for each specific type of network interface. 1.3 Simulator Circuit Theory Operation and performance of CPE are affected by the characteristics of the PSTN. Ideally, the CPE should be evaluated over the expected range of facilities and their operating characteristics. However, this is impractical and produces results that may not be repeatable. Thus, circuits were devised that would reasonably simulate those characteristics of the network that affect the CPE operation from a network harm viewpoint. The simulators are illustrated in clause 1 of ANSI/TIA-968-A. They simulate the DC voltage and resistance ranges that the CPE normally encounters when connected to the network. They also include the AC termination to be used for each application. Different simulators are used for different CPE applications. The rules permit the use of an alternative AC termination during signal power compliance tests (see Figure 1.8 in ANSI/TIA-968-A). This alternative termination may provide a better AC impedance match for signal power tests. Certain tests require the use of these simulators over specified operating ranges. Other implementations may be used provided they present DC and AC voltage and current characteristics that are equivalent to the characteristics that the applicable loop simulators in ANSI/TIA-968-A present to the CPE. If alternative loop simulators are used they should be described in the test report. The simulators specified in ANSI/TIA-968-A are for compliance testing only. They are not intended to ensure proper operation of the equipment when connected to the PSTN. Page 31 Telecommunications Industry Association 1.4 TR41.9.1-10-05-002L Test Conditions Performance of the tests described in this Document may require artificial conditions of the EUT not normally achievable. For example, a battery may be used to close a switch hook relay for application of the surge stresses in the off-hook mode when it is not practical for the equipment to be normally powered. This philosophy can be extended to the use of special EUT software. When artificial means, or companion equipment, or both, are used to condition the EUT for testing the effect on the test should be evaluated and care should be taken to ensure accurate test results. Document this in the test report. 1.5 Suggested Equipment List (SEL) The equipment itemized here will be identified in the Equipment section of each test procedure in the following format: e.g. (1) DC voltmeter SEL#22. where SEL#22 means see Suggested Equipment List, Item (22). This list itemizes the suggested requirements for test equipment needed to perform the tests in this bulletin. 1. AC current meter: range > 200 mA, minimum frequency range 15 Hz to 68 Hz, accuracy +3% Full Scale (fsc). 2. AC voltage source: output 0 Vrms to 1500 Vrms at 60 Hz, isolated with 10 mA minimum current sourcing capability. 3. AC volt meter: input impedance > 1 megohm, range 0 V to 150 Vrms, minimum frequency range 15.3 Hz to 68 Hz, accuracy +3%. 4. Applicable loop simulator circuit(s) from clause 1 of ANSI/TIA-968-A. 5. Bandpass filter: input impedance >100 kilohms, bandpass 200 Hz to 4000 Hz, cutoff frequencies at the 3 dB attenuation points, out-of-band roll-off >24 dB per octave. 6. Bandpass filter: input impedance >100 kilohms, bandpass 800 Hz to 2450 Hz, cutoff frequencies at the 3 dB attenuation points, out-of-band roll-off >24 dB per octave. 7. Bandpass filter: input impedance >100 kilohms, bandpass 2450 Hz to 2750 Hz, cutoff frequencies at the 3 dB attenuation points, out-of-band roll-off >24 dB per octave. 8. Bandpass filter: input impedance >100 kilohms, bandpass 3995 Hz to 4005 Hz, cutoff frequencies at the 3 dB attenuation points, out-of-band roll-off >24 dB per octave. Page 32 Telecommunications Industry Association TR41.9.1-10-05-002L 9. Bandpass filter: input impedance >100 kilohms, bandpass 270 kHz to 6 MHz, cutoff frequencies at the 3 dB attenuation points, out-of-band roll-off >24 dB per octave. 10. Bandpass filter: input impedance >100 kilohms, bandpass 4000 Hz to 6 MHz, cutoff frequencies at the 3 dB attenuation points, out-of-band roll-off >24 dB per octave. 11. Bandpass filter: input impedance >100 kilohms, bandpass 10 Hz to 4000 Hz, cutoff frequencies at the 3 dB attenuation points, out-of-band roll-off >24 dB per octave. 12. Bandpass filter: input impedance >100 kilohms, bandpass 100 Hz to 4000 Hz, cutoff frequencies at the 3 dB attenuation points, out-of-band roll-off >24 dB per octave. 13. Bandpass filter: input impedance >100 kilohms, bandpass 200 Hz to 3200 Hz, cutoff frequencies at the 3 dB attenuation points, out-of-band roll-off >24 dB per octave. 14. Bandpass filter: input impedance >100 kilohms, bandpass continuously variable within the cutoff frequency limits of 20 Hz to 10 MHz, cutoff frequencies at the 3 dB attenuation points, out-of-band roll-off >24 dB per octave. 15. Companion terminal equipment. 16. Concrete surface covered with 3 mm of asphalt tile. 17. Current Source: Maximum Output: 1 A. 18. Data generator: output sequence random, maximum data rate >72 kilobits per second (kbps), output to match data interface. 19. DC current meter: range 0 mA to 200 mA, accuracy +3% fsc. 20. DC current meter: range 20 microamp (uA), accuracy +3% fsc. 21. DC power supply: output level 0 V to 200 V, maximum output current >1A. 22. DC Voltmeter: input impedance >1 megohm, range 0 V to 200 V, accuracy +3% fsc. 23. Digital sampling storage oscilloscope: input impedance >1 megohm, frequency range >6 MHz, input sensitivity of 3 mV or better, trigger sensitivity of at least 10 mV or better, accuracy +3%. 24. Digital sampling storage oscilloscope: input impedance >1 megohm, frequency range >100 MHz, input sensitivity of 3 mV or better, trigger sensitivity of at least 10 mV or better, sampling rate >500 kHz, single and accumulative trace capability, channel A minus channel B, accuracy +3%. 25. DS1 transmission test set capable of sending a programmed bit stream. 26. Frequency counter: input impedance >1 megohm, frequency range from 100 Hz to at least 10 MHz, input sensitivity of 10 mV or better, resolution <1 Hz, accuracy +3 Hz. 27. Frequency generator: output impedance 600 ohms, frequency range up to at least 4 kHz, maximum output level >40 dBm, sinusoidal output. 28. Frequency selective voltmeter: frequency range from 200 Hz to at least 4 kHz, input impedance >10 kilohms, balanced input, range 1 microvolt to 1 V, accuracy +3%, bandwidth 10 Hz and 30 Hz. 29. Hearing aid probe coil assembly: see 47 CFR, 68.316. Page 33 Telecommunications Industry Association TR41.9.1-10-05-002L 30. Transverse balance bridge: See figure 4.7 of ANSI/TIA-968-A and Note (3) of this subclause. 31. Means to record oscilloscope and spectrum analyzer traces. 32. Zero level encoder/decoder, may consist of one or more discrete units which perform this function. 33. Ringing Amplifier: Output level to at least 150 Vrms superimposed on 56.5 Vdc, frequency range 15.3 Hz to 68 Hz. 34. Spectrum analyzer: input impedance >1 megohm, frequency range from 10 Hz to at least 30 MHz, sensitivity of 0.1 mV or better, resolution <1 Hz, accuracy +2 dB. 35. Summing Network: input and output impedances 600 ohms. 36. Type A metallic surge generator: 800 V minimum to 880 V maximum peak open circuit voltage at the output port with a front time (tf) of 6 µs minimum to 10 µs maximum, and a decay time (td) of 560 µs minimum to 860 µs maximum; 100 A minimum to 115 A maximum peak short circuit current, and the ability to generate these pulses in both positive and negative polarity. 37. Type A longitudinal surge generator: 1500 V minimum to 1650 V maximum peak open circuit voltage at the output port with a front time (tf) of 6 µs minimum to 10 µs maximum, and a decay time (td) of 160 µs minimum to 260 µs maximum; 200 A minimum to 230 A maximum peak short circuit current, and the ability to generate these pulses in both positive and negative polarity. 38. Power line surge generator: 2500 V minimum to 2750 V maximum peak open circuit voltage at the output port with a front time (tf) of 1 µs minimum to 2 µs maximum, and a decay time (td) of 10 µs minimum to 19 µs maximum; 1000 A minimum to 1250 A maximum peak short circuit current, and the ability to generate these pulses in both positive and negative polarity; means for preventing the surge voltage from entering the feeding AC power network. 39. Tracking generator: output impedance 100 or 135 ohm, frequency range from 10 Hz to at least 30 MHz, maximum output level 0 dBm. 40. True rms AC voltmeter: input impedance >100 kilohms, frequency range from 10 Hz to at least 4 kHz, averaging times of 0.1 s and 3.0 s, input sensitivity of 0.7 mV or better, peak indicating optional, accuracy +3%. 41. True rms AC voltmeter: input impedance >100 kilohms, frequency range from 1 kHz to at least 1 MHz, input sensitivity of 35 mV or better (referenced to 135 ohms), peak voltage and rms voltage indicating, accuracy +3%. 42. True rms current meter: range 0 mA to 500 mA, accuracy +3% fsc, measures DC and rms current simultaneously (e.g., a thermocouple type meter without DC blocking condenser at the input). 43. Voltage source: output 120 Vrms at 60 Hz, output current 10 mA. 44. Voltage source: output 300 Vrms at 60 Hz, output current 10 mA. 45. White noise generator: output impedance 600 ohms, frequency range from 200 Hz to at least 4 kHz, maximum output level of at least 10 dBm. Page 34 Telecommunications Industry Association TR41.9.1-10-05-002L 46. Zero level encoder/decoder: Equipment or companion terminal equipment capable of encoding and decoding analog signals with zero loss in the bit format appropriate for the digital interface under test. 47. Type B metallic surge generator: 1000 V minimum to 1100 V maximum peak open circuit voltage at the output port with a front time (tf) of 9 µs 2.7 µs, and a decay time (td) of 720 µs ± 144 µs; 25 A minimum to 27.5 A maximum peak short circuit current with a front time (tf) of 5 µs 1.5 µs and a decay time (td) of 320 µs ± 64 µs, and the ability to generate these pulses in both positive and negative polarity. 48. Type B longitudinal surge generator: 1500 V minimum to 1650 V maximum peak open circuit voltage at the output port with a front time (tf) of 9 µs ± 2.7 µs, and a decay time (td) of 720 µs ± 144 µs; 37.5 A minimum to 41.3 A maximum peak short circuit current with a front time (tf) of 5 µs ± 1.5 µs and a decay time (td) of 320 µs ± 64 µs, and the ability to generate these pulses in both positive and negative polarity. 49. Feeding Bridge with 2 microfarad (F) blocking capacitors and inductors of 1.8 Henries minimum at 200 Hz for analog telephone. 50. Test loops: Any real loop or commercially available artificial loop equivalent to 2.7 km and 4.6 km #26 AWG non-loaded cable. 51. Artificial ear: The IEC coupler for supra-aural earphones as described in ANSI S3.7, Method for Coupler Calibration of Earphones, is used for measuring the acoustic output of receivers that are designed to seal on its circular rim without the use of sealing putty or similar materials. The pressure response of the microphone is to be used in determining the sound pressure generated in the coupler by the receiver. 52. Standard microphone: A type (0.5 in) laboratory standard pressure microphone according to ANSI S1.15 for measuring the sound pressure generated in the artificial ear. The sensitivity of the microphone should be constant over the frequency range of 100 Hz to 5000 Hz. 53. Microphone amplifier: The frequency response characteristics of this amplifier should be constant over the frequency range from 100 Hz to 5000 Hz. The input-output characteristics of this amplifier should be linear for the range of sound pressure levels to be measured. 54. 100 Hz to 5000 Hz sinewave frequency generator, with a sweep speed slow enough not to reduce the accuracy of the measurement. The generator level should be constant over a frequency range of 100 Hz to 5000 Hz. 55. AC Voltmeter having ranges from 0.01V to 10V (full-scale reading), with an input impedance greater than 100 kilohms for bridging measurements or equal to 900 ohm for terminated measurements. 56. Signal Analyzer (FFT) having an input impedance >100 kilohms, a frequency range from 10 Hz to at least 4 kHz, and averaging times of 0.1 s and 3.0 s. 57. Spectrum analyzer: input impedance 50 ohms, frequency range from 20 Hz to at least 30 MHz, sensitivity of –130 dBm/Hz or better, resolution < 1 Hz, absolute amplitude accuracy +1.5 dB or better. Page 35 Telecommunications Industry Association TR41.9.1-10-05-002L 58. Differential amplifier with 10X passive probe set: amplifier gain 1,10, gain accuracy +1%, bandwidth DC to 10 MHz, output impedance 50 ohms, input impedance >1 megohm, input capacitance 20 pF, bandwidth limit filter upper cutoff frequency 10 kHz, filter response 6 dB/octave, minimum common mode rejection ratio 10000. 59. 100:50 ohm balun transformer: frequency range 10 kHz to 30 MHz minimum. 60. 10 dB 50 ohm pad: frequency range DC to 11 MHz minimum. 61. High-Pass Filter: fc 3 dB cut off frequency 500 kHz, f/ fc ratio 0.40:1, stop band attenuation –50 dBc. 62. Vector analyzer: input impedance of 50 ohms and 1 megohm, frequency range from DC to 30 MHz minimum, sensitivity of -130 dBm/Hz or better, resolution < 1 Hz, absolute amplitude accuracy +1.5 dB or better. 63. High-Pass Filter: fc 3 dB cut off frequency in the range of 350 kHz to 590 kHz, f/ fc ratio 0.40:1, stop band attenuation -50 dBc. 64. 135:50 ohm balun transformer: frequency range 1 kHz to 10 MHz minimum. 65. 135:50 ohm balun transformer: frequency range 20 Hz to 2 MHz minimum. 66. 135:50 ohm balun transformer: frequency range 5 MHz to 30 MHz minimum. 67. Artificial line: 2743 m (9 kft), 26 AWG. 68. Network Tone Generator capable of providing the following dual tone signals: 1. Dial tone: 350 Hz + 440 Hz, ± 0.7 %, at –10 dBm to –29 dBm per frequency applied continuously. A level of –13 dBm to –21 dBm per frequency should be satisfactory for most tests. 2. Stuttered dial tone: dial tone having a cadence of 0.1 s on, 0.1 s off, ± 10 %, for 10 cycles followed by continuous dial tone. 3. Busy tone: 480 Hz + 620 Hz, ± 1.5 %, at –21 dBm to –52 dBm per frequency with a cadence of 0.5 s on, 0.5 s off, ± 10 %. A level of –24 dBm to –32 dBm per frequency should be satisfactory for most tests. 4. Reorder tone: 480 Hz + 620 Hz, ± 1.5 %, at –21 dBm to –52 dBm per frequency with a cadence of 0.25 s on, 0.25 s off, ± 10 %. A level of –24 dBm to –32 dBm per frequency should be satisfactory for most tests. 5. Audible ringing: 440 Hz + 480 Hz, ± 1.6 %, at –16 dBm to –47 dBm per frequency with a cadence of 2 s on, 4 s off, ± 10 %. A level of –19 dBm to –27 dBm per frequency should be satisfactory for most tests. 69. Artificial ear: The Type 3.3 or Type 3.4 artificial ear described in ITUT Recommendation P.57 is used for measuring the acoustic output of receivers that are not designed to seal on the SEL#51 artificial ear. The pressure response of the microphone used with these artificial ears is to be corrected to provide the sound pressure at the entrance of the ear canal that is used to calculate loudness ratings. See IEEE 269-2002 for further information (70) 100:50 ohm BALUN transformer: frequency range 200 Hz 30 kHz minimum. Page 36 Telecommunications Industry Association TR41.9.1-10-05-002L (71) RF power meter: minimum sensitivity of 0.1 V and a minimum input impedance of 10 kohm over the frequency range from 25 kHz to 30 MHz minimum. (72) Current monitor: sensitivity of 1 volt/ampere +1%/-0%, output resistance of 50 ohm, low frequency 3 dB point of 140 Hz, high frequency 3 dB point of 35 MHz. Notes to the Suggested Equipment List: 1. Any single-ended test equipment used may require a matching/isolation device (e.g., transformer) to provide a balanced device. Similarly, an amplifier or similar device may be required to attain the required output voltage or impedance. 2. Unless otherwise stated, values in dBm are referenced to 600 ohms. 3. The transverse balance test circuit for digital circuits is given in Figure 10.2-1. 4. The specialized test equipment used in clause 15 is not itemized here. Refer to clause 15 for any equipment details. 5. The test equipment used only for the tests described in the Appendices is not itemized here. 6. To comply with 47 CFR Part 68 requirements, regular calibration of all test instruments is necessary. 7. The equipment itemized here will be identified in the Equipment Section of each test procedure in the following format: e.g. (1) DC voltmeter SEL#22, where SEL#22 means see Suggested Equipment List, Item (22). Page 37 Telecommunications Industry Association TR41.9.1-10-05-002L Page 38 Telecommunications Industry Association 1.6 TR41.9.1-10-05-002L Test Requirements Matrix To determine which criteria may be applicable to a specific product, refer to the test matrix document (in MS Excel format) that forms part of this document. Some of the tests shown may not be applicable upon examination of the product's interface or functionality, or after a reading and interpretation of the criteria. For example, for a loop start interface, the matrix shows a signal power test for network control signals. However if the product does not generate network control signals, then this test does not apply. 1.7 TSB-31-C to TIA-968-B TSB-31Description/Section Title C TIA-968-A SourceSection Within 968-A Section Within TIA-968-B Standard orSource Standard or Source Standard Addenda Addenda i FOREWORD ii TR41 MEMBERS iii TABLE OF CONTENTS viii LIST OF FIGURES 1 INTRODUCTION 2 SCOPE 3 NORMATIVE REFERENCES 4 DEFINITIONS, ACRONYMS ABREVIATIONS 5 GENERAL INFORMATION 5.1 Safety Warning About The Procedures In This Document 5.2 General Structure 5.3 Simulator Circuit Theory 5.4 Test Conditions 5.5 Suggested Equipment List COMMITTEE AND Document Page 39 Telecommunications Industry Association TR41.9.1-10-05-002L (SEL) 5.6 Test Requirements Matrix 6 ENVIRONMENTAL SIMULATION 6.1 Sequencing of Environmental Simulations TIA-968-A 6.2 Mechanical Shock TIA-968-A 4.2.1 6.3 Telephone Line Type A, Metallic Surge4.1.2.1 TIA-968-A 4.2.2.1 6.4 Telephone Line Surge4.1.2.2 Type A, Longitudinal TIA-968-A 4.2.2.2 6.5 Telephone Line Type B, Metallic Surge4.1.3.1 TIA-968-A 4.2.3.1 6.6 Telephone Line Surge4.1.3.2 Type B, Longitudinal TIA-968-A 4.2.3.2 6.7 Power Line Surge TIA-968-A 4.2.4 7 LEAKAGE CURRENT LIMITATIONS (ANALOG &4.2 DIGITAL) TIA-968-A 4.3 8 HAZARDOUS LIMITATIONS TIA-968-A 4.4 8.1 Hazardous Voltage 4.3.1 Limitations, General TIA-968-A 4.4.1 8.2 Hazardous Limitations, E&M Voltage 5.1.15 TIA-968-A, 968-A-3 8.3 Hazardous Limitations, OPS Voltage 5.1.16.5, 5.1.16.6 TIA-968-A 4.4.1.4 8.4 Hazardous Limitations, DID Voltage 5.1.17.3 TIA-968-A 4.4.1.5 8.5 Hazardous Voltage 5.2.1.2 Limitations, LADC TIA-968-A 4.4.1.6 8.6 Ringdown Voiceband Private Line & Metallic5.1.17 Channel Interface TIA-968-A 4.4.1.7 8.7 Physical Leads 4.3.2 TIA-968-A, 968-A-2 8.8 Ringing Sources 4.3.3 TIA-968-A 4.4.4 8.9 Intentional Operational 4.3.4.1 Paths to Ground TIA-968-A 4.4.5.1 8.10 Intentional Protective Paths 4.3.4.2 to Ground TIA-968-A 4.4.5.2 4.1 TIA-968-A 4.1.1 4.1.4 VOLTAGE Separation of 4.3 Page 40 4.2 TIA- TIA- 4.4.1.1, 4.4.1.2, 4.4.1.3 4.4.2, 4.4.3 Telecommunications Industry Association TR41.9.1-10-05-002L 9 SIGNAL LIMITATIONS POWER 4.4.1.1 9.1 Voiceband Signal Power Not Network Control5.1.2 Signals TIA-968-A-1, TIA4.5.2.1 968-A-3 9.2 Voiceband Signal Power 5.1.3 Network Control Signals TIA-968-A, 968-A-3 9.3 Through Transmission Equipment - DC Conditions5.1.5.1 for On-premise TIA-968-A-3 4.5.2.3.1 9.4 Through Transmission 5.1.5.2 Equipment - Data TIA-968-A 4.5.2.3.2 9.5 Voiceband Signal Power 4.4.2.2 Data TIA-968-A, 968-A-1 9.6 Through Transmission 4.7.2 4.7.3 Port To Port Amplification TIA-968-A 4.5.2.5.1 9.7 Through Transmission - SF 4.7.5 cutoff TIA-968-A 4.5.2.5.1(7) 9.8 Through Transmission SF/Guard Band TIA-968-A 4.5.2.5.2 9.9 Return Loss, Tie Trunk, 5.1.5.4(c1) Two Wire TIA-968-A 4.5.2.6.1 9.10 Return Loss, Tie Trunk, 5.1.5.4(c2) Four Wire TIA-968-A 4.5.2.6.2 9.11 Transducer Loss, Trunk, Four Wire 5.1.5.4(c4) TIA-968-A 4.5.2.6.3 9.12 DC Conditions, OPS 5.1.16 TIA-968-A 4.5.2.7 9.13 Signal Power 3995-4005 Hz - Not Network Control5.1.6.1 Signals TIA-968-A 4.5.3.1 9.14 Through Transmission 3995-4005 Hz vs 600-40005.1.6.2 Hz TIA-968-A 4.5.3.2 9.15 Non-LADC Longitudinal 5.1.7 Voltage, 0.1-4 kHz TIA-968-A 4.5.4 9.16 Non-LADC Metallic 5.1.8.1, 5.1.8.2 Voltage, 4 kHz-30 MHz TIA-968-A 4.5.5.1 9.17 Non-LADC Longitudinal 5.1.8.3, 5.1.8.4 Voltage, 4 kHz-6 MHz TIA-968-A 4.5.5.2 9.18 Metallic Voltage, 0.01 kHz5.2.1.4.1, 5.2.1.4.2 30 MHz, LADC TIA-968-A 4.5.6.1, 4.5.6.2 9.19 Longitudinal Voltage, 0.015.2.1.4.3 TIA-968-A 4.5.6.3 TIA-968-A 4.7.4 Tie Page 41 4.5 TIA- TIA- 4.5.2.2 4.5.2.4 Telecommunications Industry Association TR41.9.1-10-05-002L kHz-6 MHz, LADC 9.20 Pulse Repetition Subrate/PSDS Rate, 5.2.2.1.1 9.21 Encoded Analog Content 9.22 Equivalent PSD for 5.2.2.1.4 Maximum Output, Subrate TIA-968-A 4.5.8.1.3 9.23 Average Power, Subrate, Non-Secondary and5.2.2.1.5, 5.2.2.1.6 Secondary Channel Rates TIA-968-A 4.5.8.1.4, 4.5.8.1.5 9.24 Pulse Subrate/PSDS TIA-968-A 4.5.8.1.6, 4.5.8.3.2 9.25 Average Power, Subrate TIA-968-A 4.5.8.1.7 9.26 Pulse Repetition 1.544 Mb/s Rate, 5.2.4.1 TIA-968-A 4.5.8.2.1 9.27 Pulse Mb/s 1.544 5.2.4.2 TIA-968-A 4.5.8.2.2, 4.5.8.2.3 9.28 Output Power, 1.544 Mb/s 5.2.4.4 TIA-968-A 4.5.8.2.4 9.29 Unequipped channels TIA-968-A-3 4.5.8.2.6 9.30 Conditioning ADSL EUT to Transmit Continuously 9.31 Total Average Power,5.3.2.1.1, ADSL Terminal Equipment 5.3.5.2.1 5.3.3.1.1, TIA-968-A-3 4.5.9.1.1 9.32 Power Spectral Density,5.3.2.1.2, ADSL Terminal Equipment 5.3.5.2.2 5.3.3.1.1, TIA-968-A-3 4.5.9.1.2, 4.5.9.1.3 9.33 Longitudinal Voltage, ADSL Equipment TIA-968-A-3 4.5.9.1.4 9.34 Voiceband Signal Power Non-approved external5.1.4 signal sources TIA-968-A-3 4.5.2.2 10 TRANSVERSE BALANCE 4.6 LIMITATIONS TIA-968-A 4.6 10.1 Transverse Analog TIA-968-A 4.6.2 10.2 Transverse Balance, Digital 11 ON-HOOK IMPEDANCE 4.7 LIMITATIONS TIA-968-A 4.7 11.1 DC Resistance TIA-968-A 4.7.2.1, 4.7.2.2 TIA-968-A TIA-968-A, 968-A-1 4.5 Template, 5.2.2.1.7 Template, sub-rate 5.2.2.1.8 5.2.4.6 Output Terminal5.3.2.3 Balance, 5.1.10 5.2.2.2, 5.2.4.7, 5.3.2.2 5.2.3.2, 5.1.11.2.1, 5.1.11.2.2 Page 42 4.5.8.1.1, 4.5.8.3.1 TIA-4.5.8.1.2, 4.5.8.4, 4.5.8.2.5, 4.5.8.3, 4.5.10 TIA-968-A, TIA968-A-3, TIA-968-4.6.3, 4.6.4, 4.6.5 A-4 Telecommunications Industry Association TR41.9.1-10-05-002L 11.2 DC Current During Ringing, 5.1.11.2.3 Loop Start TIA-968-A 4.7.2.3 11.2 DC Current During Ringing, 5.1.12.2.1 Ground Start TIA-968-A 4.7.3.1 11.3 AC Impedance During Ringing, Loop Start5.1.11.2.4, 5.1.11.2.5 (Metallic and Longitudinal) TIA-968-A 4.7.2.4, 4.7.2.5 11.3 AC Impedance During Ringing, Ground Start5.1.12.2.2 (Metallic) TIA-968-A 4.7.3.2 11.4 REN Calculation TIA-968-A, 968-A-1 11.5 OPS Ring Trip, PBX with 5.1.15.7 DID TIA-968-A 11.6 Transitioning to the Off5.1.11.3, 5.1.12.3 Hook State and Make-Busy TIA-968-A, TIA968-A-1, TIA-968-4.7.8 A-4 11.7 Manual programming 5.1.11.3.1, 5.1.12.3.1 repertory numbers TIA-968-A 4.7.8.1 11.8 Automatic Stuttered Tone Detection 5.1.11.3.2, 5.1.12.3.2 TIA-968-A 4.7.8.2 12 BILLING PROTECTION 4.4 TIA-968-A 4.8 12.1 Call Duration Equipment, Circuitry for Data Protective4.4.1.1 TIA-968-A 4.8.1.1 12.2 Call Duration Applications, Equipment for Data Terminal4.4.1.2 TIA-968-A 4.8.1.2 12.3 On-Hook Analog Power, 4.4.2.1, 4.4.2.2 TIA-968-A 4.8.2 12.4 Off-Hook Loop Current 5.1.11.4, 5.1.12.4 TIA-968-A 4.8.3 12.5 Signaling Analog Interference, 4.4.3.1 TIA-968-A 4.8.4.1 12.6 Signaling Digital Interference, 4.4.3.2 TIA-968-A 4.8.4.2 12.7 On-Hook Digital TIA-968-A 4.8.5 12.8 Signaling Duration, 1.544 4.4.1 Mb/s TIA-968-A 4.8.6 12.9 Operating for DID TIA-968-A 4.8.7 5.1.11.2.7, 5.1.11.2.8 Signal Signal Dial Power, 4.4.2.3, 4.4.2.3 Requirements 5.1.13.4, 5.2.4.9 Page 43 TIA- 4.7.4, 4.7.5 4.7.6 Telecommunications Industry Association 13 14 TR41.9.1-10-05-002L CONNECTORS 4.6 TIA-1096 4, 5 Wiring Configurations 4.6 4.6.2 TIA-968-A-4 6.2.2 SHDSL, HDSL2, HDSL4 5.3.4, 5.3.5, 5.3.6 TERMINAL EQUIPMENT 14.1 Metallic Signals 14.2 Longitudinal Voltage 5.3.1.1, 5.3.5.1, 5.3.6.1, 5.3.8.1, 5.3.9.1 5.3.1.3, Output5.3.5.4 5.3.7.3, 5.3.9.3 , TIA-968-A-3, TIA968-A-4 5.3.4.1, 5.3.5.2,TIA-968-A-3, TIA4.5.9.2.1, 4.5.9.2.4 5.3.7.1,968-A-4 5.3.4.3, 5.3.6.3,TIA-968-A-3, TIA4.5.9.2.3 5.3.8.3,968-A-4 14.3 Transverse Balance 5.3.2.2, 5.3.5.3, 5.3.7.2, 5.3.9.2 15 HEARING-AID COMPATIBILITY Part 68 15.1 Hearing Aid Compatibility Part 68 - 68.316 Magnetic Field Intensity Part 68 68.316 15.2 Hearing Aid Compatibility Part 68 - 68.317 Volume Control Part 68 68.317 16 MISCELLANEOUS Part 68 - 68.318 Part 68 68.318 16.1 Limitations Redialing Part 68 - 68.318(b) Part 68 68.318(b) 16.2 Line Seizure by Automatic Part 68 - 68.318(c) Telephone Dialing Systems Part 68 68.318(c) 16.3 Facsimile Machine Sender Part 68 - 68.318(d) Identification Part 68 68.318(d) 16.4 Equal Access to Common Part 68 - 68.318(e) Carriers Part 68 68.318(e) A TEMPLATES DIGITAL PULSES A.1 Templates for Subrate and PSDS Digital Pulses A.2 Templates for ISDN PRA and 1.544 Mb/s Digital Pulses B EXAMPLE CALCULATIONS OF WAVEFORM ENERGY LEVELS C ALTERNATE on Automatic 5.3.4.2, 5.3.6.2, TIA-968-A-3 5.3.8.2, 4.6.5 Part 68 FOR Page 44 Telecommunications Industry Association TR41.9.1-10-05-002L TRANSVERSE BALANCE, DIGITAL EUT D Test Procedures For Passive Splitter Filters and Passive Micro-Filters TIA-968-A-4 Page 45 4.6.1.4 Telecommunications Industry Association TR41.9.1-10-05-002L ENVIRONMENTAL SIMULATION TIA-968-B, 4.1 1.8 Sequencing of Environmental Simulations TIA-968-B subclause 4.1 requires that "Unpackaged Certified Terminal Equipment and Certified Protective Circuitry shall comply with all the criteria specified in this standard, both prior to and after the application of each of the mechanical and electrical stresses specified in this section...." For practical reasons, the accepted method for equipment which has not been affected by environmental simulations is to perform complete electrical testing, not after each stress but once after all stresses. Generally, testing should be performed serially; that is, the unit should be tested for compliance to the electrical requirements, then subjected to the stresses of subclause 6, and finally the unit should be reexamined for compliance to the technical requirements. This procedure provides an opportunity to evaluate the effects of the environmental stresses on the unit without uncertainties resulting from the testing of several different units non-serially. Circumstances may occasionally require parallel testing of the equipment. In this case, one unit is subjected to the environmental stresses of subclause 6 while a second unit is maintained in a non-stressed condition. The two units are then examined for compliance to the requirements of TIA-968-B clause 4. This type of test plan has several limitations, particularly when the units used for testing are engineering samples or prototypes. Since one of the objects of the environmental stress testing is to note the effect of the stresses on the equipment under test, parallel testing of two units may not always provide enough information. The testing should be performed on a single unit with tests performed serially as discussed above. Shown in Figure 6.1-1 is a recommended serial test sequence, with notes and allowances for failures experienced during test, component replacements and last minute design changes. Any sequence of environmental simulations may be followed but should be from least to most destructive. The sequence shown in Figure 6.1-1 is typical of 'real-world' environmental stresses that are experienced by certified equipment. Operational tests may be performed once or several times, e.g. after any of the simulations if failure appears probable or after all simulations have been performed. The EUT may be considered compliant when all applicable pre- and post-environmentally obtained data meets 47 CFR Part 68 and TIA-968-B requirements. If environmental stresses impair the function of the EUT, good engineering judgment should be exercised in determining whether the EUT is compliant. An abbreviated array of post-environmental data may be sufficient to verify compliance. Alternatively, it may be determined that some repair or special techniques are in order to adequately profile the EUT’s post-environmental condition. Page 46 Telecommunications Industry Association TR41.9.1-10-05-002L Example: Following the sequence suggested, the application of the Type A metallic surge voltages to the EUT may permanently open the switchhook, which by itself, is not a compliance failure. However, with the switchhook permanently open, it is thereafter impossible to evaluate the signal level limitation circuitry, which may also be malfunctioning, perhaps as a result of thermal conditioning. In an actual installation, depending on locale and other elements, environmental conditions may thermally stress the equipment but subject it to infrequent lightning discharge. Such equipment may, via thermal susceptibility of signal power limitation circuitry, cause harm to the network. Engineering judgment will determine appropriate procedures in such circumstances. Operational or electrical testing is not required during environmental simulations. The EUT should be allowed to stabilize to ambient conditions before evaluation testing resumes. Page 47 Telecommunications Industry Association TR41.9.1-10-05-002L Page 48 Telecommunications Industry Association TR41.9.1-10-05-002L Figure 6.1-1 Environmental Flowchart Page 49 Telecommunications Industry Association TR41.9.1-10-05-002L Notes for Figure 6.1-1: 1. INITIAL Initial electrical tests are performed on a fully functional EUT. If the EUT has functions which are not operational but which do not affect compliance, this should be noted in the report. 2. ENVIRONMENTAL NOTES: Environmental simulation may take place in ANY sequence; however, based on engineering analysis of the particular unit under test, simulations should be done in the order of potentially least destructive to most destructive. Experience has shown the sequence diagrammed to be the least to most destructive for most equipment. Engineering judgment may suggest an operational test or a complete test to 47 CFR Part 68 / TIA-968-B requirements if it appears the next simulation may be destructive, or the previous one may have damaged the EUT. 3. OPERATIONAL FAILURE: (Example: Data modem will not transmit data.) “Operational failure” means the device will not function normally or as intended. Measurement may or may not be necessary. Such a condition does not mean failure of 47 CFR Part 68 / TIA-968-B. This can only be determined by completing all applicable tests on the equipment and verifying compliance with 47 CFR Part 68 / TIA-968B. 4. COMPONENT REPLACEMENT Replacement of failing components and continuation of the post-simulation testing should only occur after good engineering analysis indicates that this is an acceptable procedure. The replacement components should be subjected to the same conditioning as the EUT has encountered to that point. 5. POST - ENVIRONMENTAL TESTS For a unit, which has not experienced failures due to environmental conditioning, to be considered compliant, it should have pre- and post -environmental simulation test data, thus verifying compliance with all applicable 47 CFR Part 68 and TIA-968-B requirements. For a unit which has experienced failures due to environmental conditioning to be considered compliant, good engineering judgment should be exercised in determining which 47 CFR Part 68 / TIA-968-B requirements remain applicable, and what comparison post-environmental data is required (and what techniques are employed in acquiring such data). Page 50 Telecommunications Industry Association TR41.9.1-10-05-002L 6. REPAIR, REDESIGN OR RE-SPECIFICATION OF COMPONENTS: Since changes may invalidate entire blocks of pre-environmental data, usually a return to the beginning of the test cycle is in order. If re-entry at a later point in the flow chart appears permissible, it should be noted in the approval report with justification. 7. APPROVAL DOCUMENTATION or APPLICATION SUBMISSION Refer to current issue of TIA/TSB-129-A. Page 51 Telecommunications Industry Association 1.9 TR41.9.1-10-05-002L Mechanical Shock TIA-968-B, 4.1.1 1.9.1 Background Terminal equipment may be subjected to mechanical shock during shipping, installation, and use. This shock may damage or reposition components in circuitry affecting compliance. Mechanical shocks condition the EUT to reveal component or position weaknesses. 1.9.2 Purpose To simulate handling of terminal equipment during installation and use. 1.9.3 Equipment (1) Concrete surface SEL#16. Note: Refer to subclause 5.5 for equipment details. 1.9.4 Equipment States Subject To Test Unpackaged and unpowered. 1.9.5 Procedure Refer to TIA-968-B subclause 4.1.1 for procedure and equipment weight classification. 1.9.6 Alternative Methods None. 1.9.7 Suggested Test Data 1. Weight and use classification of EUT. 2. Number of drops. 3. Height and orientation of drop. 4. Observed results. Page 52 Telecommunications Industry Association TR41.9.1-10-05-002L 1.9.8 Comments None. 1.10 Telephone Line Surge - Type A, Metallic. TIA-968-B, 4.1.2.1 1.10.1 Background The metallic surge is the voltage resulting from the longitudinal-to-metallic conversion when one of the two primary protectors operates. Surge tests simulate longitudinal voltage transients in the telephone company lines due to lightning. The front and decay times and crest values are derived from actual measurements with primary protectors in typical installations. These surges, particularly in equipment off-hook conditions, can easily cause compliance-related equipment failure via destruction of sensitive electronic circuitry as the surges appear in the same mode as network voice and data signals and signaling information. 1.10.2 Purpose To simulate induced metallic surge voltages on a telephone line which could result from lightning. 1.10.3 Equipment 1. Surge Generator SEL#36. Note: Refer to subclause 5.5 for equipment details. 1.10.4 Equipment States Subject To Test 1. On-hook. 2. Off-hook. 3. Any other state in which the EUT is normally connected to the network. 1.10.5 Procedures WARNING: ADEQUATE SAFETY PRECAUTIONS SHOULD BE OBSERVED Page 53 Telecommunications Industry Association TR41.9.1-10-05-002L 1. Refer to TIA-968-B subclause 4.1.1.1.1 for the connections to be surged. 2. Place the equipment in the state to be tested. 3. Apply a surge of each polarity. 4. Check EUT operation and record the results. 5. Change states as necessary and repeat Step (2) through Step (4). 1.10.6 Alternative Methods None. 1.10.7 Suggested Test Data 1. Equipment state(s). 2. Leads tested. 3. Observed Results. 1.10.8 Comments 1. All EUT leads not being surged should be terminated in a manner no less severe than that which occurs in normal use. 2. A loop simulator may be used as long as it does not interfere with application of stress to the EUT. 3. The EUT is permitted to reach certain failure modes after application of these surges. See TIA-968-B subclause 4.1.2.3 for discussion. Page 54 Telecommunications Industry Association TR41.9.1-10-05-002L 1.11 Telephone Line Surge - Type A, Longitudinal. TIA-968-B, 4.1.2.2 1.11.1 Background The longitudinal surge is the ground potential rise resulting from current in the primary protector grounding conductor as a result of both primary protectors operating. Equipment with a good dielectric/low capacitance barrier does not usually sustain damage as a result of this surge. 1.11.2 Purpose To simulate longitudinal surge voltages which could result due to lightning strikes on the telephone line. 1.11.3 Equipment 1. Surge generator SEL#37. Note: Refer to subclause 5.5 for equipment details. 1.11.4 Equipment States Subject To Test 1. On-hook. 2. Off-hook. 3. Any other state in which the EUT is normally connected to the network. 1.11.5 Procedure WARNING: ADEQUATE SAFETY PRECAUTIONS SHOULD BE OBSERVED Refer to TIA-968-B subclause 4.1.2.2.1 for the connections to be surged. Page 55 Telecommunications Industry Association TR41.9.1-10-05-002L 1. Place the EUT in the state to be tested. 2. Apply a surge of each polarity. 3. Check EUT operation and record the results. 4. Change states as necessary and repeat Step (3) and Step (4). 1.11.6 Alternative Methods None. 1.11.7 Suggested Test Data 1. Equipment state(s). 2. Leads tested. 3. Observed Results. 1.11.8 Comments 1. Terminate EUT leads not being surged in a manner which is no less severe than occurs in normal use. 2. A loop simulator may be used as long as it does not interfere with application of stress to the EUT. 3. The EUT is permitted to reach certain failure modes after application of these surges. See TIA-968-B subclause 4.1.2.3 for discussion. Page 56 Telecommunications Industry Association TR41.9.1-10-05-002L 1.12 Telephone Line Surge - Type B, Metallic. TIA-968-B, 4.1.3.1 1.12.1 Background It is possible for low energy transients to couple to the telephone lines and enter an interface without tripping the secondary protectors. The transients in TIA-968-B subclause 4.1.3 simulate these low energy disturbances and address potential harms to the network after their incidence upon an interface. There is a significant body of data which indicates that the energy of the FCC Type A surge is very severe relative to actual surges that occur. The concern with the FCC Type A surge is that the response of equipment to lower energy surges, which are more common, is unknown. The metallic surge is the voltage resulting from the longitudinal-to-metallic conversion when one of the two primary protectors operates. Surge tests simulate longitudinal voltage transients in the telephone company lines due to lightning. The front and decay times and crest values are derived from actual measurements with primary protectors in typical installations. These surges, particularly in equipment off-hook conditions, can easily cause compliance-related equipment failure via destruction of sensitive electronic circuitry as the surges appear in the same mode as network voice and data signals and signaling information. 1.12.2 Purpose To simulate low energy induced metallic surge voltages on a telephone line which could result from lightning. 1.12.3 Equipment 1. Surge Generator SEL#47. Note: Refer to subclause 5.5 for equipment details. 1.12.4 Equipment States Subject To Test 1. On-hook. 2. Off-hook. 3. Any other state in which the EUT is normally connected to the network. Page 57 Telecommunications Industry Association TR41.9.1-10-05-002L 1.12.5 Procedures WARNING: ADEQUATE SAFETY PRECAUTIONS SHOULD BE OBSERVED Refer to TIA-968-B subclause 4.1.3.1 for the connections to be surged. 1. Place the equipment in the state to be tested. 2. Apply a surge of each polarity. 3. Check EUT operation and record the results. 4. Change states as necessary and repeat Step (2) through Step (4). 1.12.6 Alternative Methods None. 1.12.7 Suggested Test Data 1. Equipment state(s). 2. Leads tested. 3. Observed Results. 1.12.8 Comments 1. All EUT leads not being surged should be terminated in a manner no less severe than that which occurs in normal use. 2. A loop simulator may be used as long as it does not interfere with application of stress to the EUT. 3. Verify that the EUT complies with the failure criteria outlined in TIA-968-B subclause 4.1.3.3 after surge. Page 58 Telecommunications Industry Association TR41.9.1-10-05-002L 4. The surge generator waveform parameters specified are based on an analysis of the surge generator circuit of ITU Recommendation K.21. This recommendation specifies a nominal open circuit voltage waveform of 10 microseconds (s) x 700 microseconds (s). Commercial surge generators are generally built to the ITU Recommendation and the 10 microseconds (s) x 700 microseconds (s) waveform provided is within the tolerances of the 9 microseconds (s) x 720 microseconds (s) open circuit waveform specified in TIA-968-B subclauses 4.1.2.1.2 – 4.1.2.2.2. Surge generators conforming to the ITU Recommendation also meet TIA-968-B subclauses 4.1.2.1.2 – 4.1.2.2.2. Page 59 Telecommunications Industry Association TR41.9.1-10-05-002L 5. Verify that the equipment is capable of withstanding the energy of the Type B surges without causing permanent opening or shorting of the interface circuit and without sustaining other damages that will affect compliance. The EUT is not required to be fully operational. These criteria for allowable failure modes help ensure that a protection strategy for meeting the acceptable failure mode criteria of the Type A surge does not mask other potentially harmful failure modes at lower energies. 6. Where the EUT will not switch from an on-hook to an off-hook state after stress, due to a failure of some circuitry that controls or powers a hookswitch relay or other similar device, an artificial means should be used to place the EUT in the off-hook state. All applicable off-hook tests and all on-hook tests should be performed. 7. The EUT is not to open the interface circuit by opening a trace, fuse, or component in the interface circuit. Page 60 Telecommunications Industry Association TR41.9.1-10-05-002L 1.13 Telephone Line Surge - Type B, Longitudinal. TIA-968-B, 4.1.3.2 1.13.1 Background The longitudinal surge is the ground potential rise resulting from current in the primary protector grounding conductor as a result of both primary protectors operating. Equipment with a good dielectric/low capacitance barrier usually does not sustain damage as a result of this surge. 1.13.2 Purpose To simulate low energy longitudinal surge voltages induced by lightning. 1.13.3 Equipment 1. Surge generator SEL#48 Note: Refer to subclause 5.5 for equipment details. 1.13.4 Equipment States Subject To Test 1. On-hook. 2. Off-hook. 3. Any other state in which the EUT is normally connected to the network. 1.13.5 Procedure WARNING: ADEQUATE SAFETY PRECAUTIONS SHOULD BE OBSERVED Refer to TIA-968-B subclause 4.1.2.2.1 for the connections to be surged. 1. Place the EUT in the state to be tested. 2. Apply a surge of each polarity. Page 61 Telecommunications Industry Association TR41.9.1-10-05-002L 3. Check EUT operation and record the results. 4. Change states as necessary and repeat step (3) and step (4). 1.13.6 Alternative Methods None. 1.13.7 Suggested Test Data 1. Equipment state(s). 2. Leads tested. 3. Observed Results. 1.13.8 Comments 1. Terminate EUT leads not being surged in a manner which is no less severe than occurs in normal use. 2. A loop simulator may be used as long as it does not interfere with application of stress to the EUT. 3. Verify that the EUT complies with the failure criteria outlined in TIA-968-B subclause 4.1.2.3 after surge. 4. The surge generator waveform parameters specified are based on an analysis of the surge generator circuit of ITU Recommendation K.21. This recommendation specifies a nominal open circuit voltage waveform of 10 microseconds (s) x 700 microseconds (s). Commercial surge generators are generally built to the ITU Recommendation and the 10 microseconds (s) x 700 microseconds (s) waveform provided is within the tolerances of the 9 microseconds (s) x 720 microseconds () open circuit waveform specified in TIA-968-B subclauses 4.1.2.1.2 – 4.1.2.2.2. Surge generators conforming to the ITU Recommendation also meet TIA-968-B subclauses 4.1.2.1.2 – 4.1.2.2.2. 5. Verify that the equipment is capable of withstanding the energy of the Type B surges without causing permanent opening or shorting of the interface circuit and without sustaining other damages that will affect compliance. The EUT is not required to be fully operational. These criteria for allowable failure modes help ensure that a protection Page 62 Telecommunications Industry Association TR41.9.1-10-05-002L strategy for meeting the acceptable failure mode criteria of the Type A surge does not mask other potentially harmful failure modes at lower energies. 6. Where the EUT will not switch from an on-hook to an off-hook state after stress, due to a failure of some circuitry that controls or powers a hookswitch relay or other similar device, an artificial means should be used to place the EUT in the off-hook state. All applicable off-hook tests, and all on-hook tests should be performed. 7. The EUT is not to open the interface circuit by opening a trace, fuse, or component in the interface circuit. Page 63 Telecommunications Industry Association TR41.9.1-10-05-002L 1.14 Power Line Surge TIA-968-B, 4.1.4 1.14.1 Background Lightning induced transients may enter the equipment via the AC power lines. As such, they will typically be superimposed on the normal line voltage and may cause damage or destruction to the ac-line-input dielectric barrier. 1.14.2 Purpose To simulate lightning induced surges on the AC power lines. 1.14.3 Equipment 1. Surge generator SEL#38. Note: Refer to subclause 5.5 for equipment details. 1.14.4 Equipment States Subject To Test 1. Powered with EUT power switch ON. 2. Powered with EUT power switch OFF. 1.14.5 Procedure WARNING: ADEQUATE SAFETY PRECAUTIONS SHOULD BE OBSERVED Refer to TIA-968-B subclause 4.1.4.1 for the connections to be surged. 1. Apply three surges of each polarity to the power connection of the EUT. 2. Change EUT states and repeat Step (1). 3. Perform an operational check of the EUT and record the results. Page 64 Telecommunications Industry Association TR41.9.1-10-05-002L 1.14.6 Alternative Methods None. 1.14.7 Suggested Test Data 1. Voltage. 2. Equipment state(s). 3. Number of surges and polarity. 4. Observed results. 1.14.8 Comments 1. All equipment leads not being surged should be terminated in a manner which is no less severe than that which occurs in normal use. 2. The EUT is permitted to reach certain failure modes after application of these surges. See TIA-968-B subclause 4.1.4.2 for discussion. 3. Configure the test arrangement to apply the surge to the EUT without affecting, or being affected by, the AC power line. LEAKAGE CURRENT LIMITATIONS (ANALOG AND DIGITAL) TIA-968-B, 4.2 7.1 Background Leakage current limitations ensure that telephone connections are adequately insulated against voltages hazardous to telephone company personnel as a result of supply voltages within the equipment or the result of accidental contact with commercial power on 1) exposed conductive surfaces, 2) leads to other equipment, e. g. serial, parallel, LAN, WAN, or 3) other leads to the network interface. In this case, the leakage current limit is merely a threshold for determining whether dielectric breakdown has occurred. It should not be confused with leakage current limits that relate to product safety. Such limits typically specify the maximum current permitted Page 65 Telecommunications Industry Association TR41.9.1-10-05-002L through an impedance simulating the human body connected between exposed conductive surfaces and ground or between exposed conductive surfaces. The 1000-volt requirement is based in part upon the fact that potentials as high as 1000 V peak can reach certified terminal equipment or certified protective circuitry where carbon block protectors have not fired. The 1500-volt requirement is based upon commonly used criteria for testing transformer insulation that specifies using 1000 volts plus twice the rated primary voltage. The increase in leakage current limit allowed for multi-unit equipment is for those cases where more than one unit is connected to the same telephone connection leads. It takes into account the increased leakage current resulting from the capacitance in: 1) interconnecting cables and 2) the parallel combination of dielectric barriers in each unit. 7.2 Purpose To verify the integrity of the dielectric barrier between the network and power line and the equipment connections of the EUT. 7.3 Equipment 1. AC voltage source SEL#2. 2. True rms voltmeter SEL#40 (qty 2). Note: Refer to subclause 5.5 for equipment details. Page 66 Telecommunications Industry Association TR41.9.1-10-05-002L 7.4 Equipment States Subject to Test The EUT-to-network barrier test (1000 V) should be performed in a sufficient number of operational states to verify compliance of all dielectric barrier components, e.g., line transformers, opto-isolators, relays and printed circuit boards. By using the required isolated source, these tests may be performed with or without power applied to the EUT. Artificial means to achieve the various test modes may be used when required, provided the method used does not affect the current path. For example, the network connections of a switchhook relay is not to be manually shorted. Instead, an external supply, such as a battery, may be used to activate the relay to achieve the off-hook mode. For the EUT-to-power-line barrier test (1500 V), the power switch is in the ON position, but the EUT is not powered so that the power path is completed when the high voltage is applied. 7.5 Procedure WARNING: ADEQUATE SAFETY PRECAUTIONS SHOULD BE OBSERVED 1. Connect the EUT to the test circuit of Figure 7-1. 2. Select the appropriate EUT test points, and connect to the test setup output. 3. Place the EUT in the first test state. 4. Gradually increase the test voltage to the level required for the connections under test, over a 30-second period. Maintain the maximum voltage level for an additional 60 s. 5. Monitor the resulting current and the applied voltage level for the 90-second test period. 6. Record the maximum current measured during this period. 7. Adjust the source for zero-volt output. 8. Repeat Step (4) through Step (7) for all applicable operational states. 9. Repeat Step (2) through Step (8) for all specified combinations of electrical connections as listed in subclause 4.2 of TIA-968-B. Page 67 Telecommunications Industry Association TR41.9.1-10-05-002L 7.6 Alternative Methods The 1500 VAC test may be conducted using a DC equivalent of 2121 VDC. 7.7 Suggested Test Data Identify electrical connections or test points. Voltage applied (V rms). Maximum current (mA peak). 7.8 Comments 1. Leads may be tested as a group or as indicated in subclause 4.2 of TIA-968-B. 2. EUTs with a nonmetallic case having some exposed metallic surfaces (e.g., screws, hinges, ventilation or access opening) may be tested by wrapping the case in a conductive foil, placing it on a conductive sheet, or immersing it in a container filled with 0.25-inchdiameter (maximum) conductive particles, as appropriate. The voltage is applied between the conducting element and the other relevant test points. 3. As shown in the test setup, the leakage current is equal to the voltage measured across the 1000-ohm resistor divided by 1000. 4. There are three intentional paths to ground considered: 1. Operational paths, such as ground start leads, are excluded from testing. An operational path is identified as having a DC resistance at operating voltages (battery or ringing). The current handling capability of the path is evaluated under subclause 4.3.4.1 of TIA-968B. Another example of an excluded operational path is the Tip Ground state of a central office implemented telephone because it provides an intentional operational path, from the tip conductor through a reset electromagnet in series with a coin relay, to ground. 2. Protective paths, such as MOVs and surge suppressors, are removed before testing. A protective path is identified as being conductive at leakage current test voltages (1000 V - a surge arrestor fires to protect equipment from such voltages), but is an insulator at operational voltages. The insulation properties of the component removed is evaluated at Page 68 Telecommunications Industry Association TR41.9.1-10-05-002L 120 V under subclause 4.3.4.2 of TIA-968-B. Typically, a suppressor is rated at greater than 130 V to be transparent to ringing voltages. 3. Filter paths on the interface circuit are left in place during testing. Filter components should withstand 1000 V, which provides the capability to withstand surges. These paths are identified as not conductive for DC. To pass a 1000 V test, a capacitor needs about a 400 WVDC rating. These are special capacitors, designated “X-capacitors”, or “Ycapacitors”. 5. EMI filtering on the AC input to the EUT may be disconnected from ground. An engineering evaluation is to be made and an attestation provided if the filter cannot be isolated from ground. Alternatively, power supplies may incorporate integrated line filter networks, the removal of which would reduce the effect of the applied voltage in evaluating the characteristics of the EUT. In such cases, it may be appropriate to perform this test using a DC test voltage. The maximum DC test voltage would correspond to the peak value of the specified AC test voltage, and the test should be performed in both polarities. 5. If the EUT has a path to ground (or a path close to ground potential) and the high voltage source is not isolated, measured current inaccuracies may occur due to ground loops. 5. An EUT which has both an intentional operational and an intentional protective path to ground needs to meet only the requirements of subclause 4.3.4.1 of TIA-968-B referred to in subclause 7.4 of this Document, provided that it uses varistors, thyristors, or other protection devices to ground. Examples of these circuits are DID, OPS, E&M, and Ground Start (which typically utilize ground for operation). Page 69 Telecommunications Industry Association TR41.9.1-10-05-002L 6. When conducting the 1500V AC dielectric test between AC power and tip-ring interface circuit, high leakage current may exist due to loopback current through common ground and filter paths on AC power side and interface circuit. 5. 1. A 1500 V AC voltmeter or a resistive voltage divider and high impedance voltmeter may be used. 2. The 50-kilohm current-limiting resistor is optional but is recommended to reduce the possibility of damage in case of insulation breakdown. 3. A true rms or rms-calibrated voltmeter may be used to measure a converted rms current limit. Alternatively, an oscilloscope may be used to measure peak current. Precautions should be taken for isolation of high voltage differential or current probes. Figure 7-1. Leakage Current Page 70 Telecommunications Industry Association TR41.9.1-10-05-002L HAZARDOUS VOLTAGE LIMITATIONS TIA-968-B, 4.3 1.15 Hazardous Voltage Limitations, General TIA-968-B, 4.3.1 1.15.1 Background When telephone company personnel perform maintenance and repair on the telephone wiring, they are aware of the various voltages which can be present under normal operating conditions. If unexpected foreign potentials appear at tip and ring, these personnel may be injured either by the voltage itself or as a result of physical reaction to this voltage. Past experience has shown that voltages above 70 volts which are present for more than one second are hazardous. 1.15.2 Purpose This test is to ensure that the EUT does not apply voltages to tip and ring which are not part of the normal operation of the telephone network. 1.15.3 Equipment Digital sampling oscilloscope SEL #23 1.15.4 Equipment States Subject to Test Any condition which might cause AC voltage to appear on network connections other than network control signaling, alerting, and supervision. 1.15.5 Procedure 1. Connect the oscilloscope leads to tip and ring leads. 1. Place the EUT in the state being measured. 2. Observe the AC voltage. If no voltages greater than 70 volts peak are observed, record the maximum peak voltage. 3. If voltage greater than 70 volts is observed, record the peak voltage and the time the voltage is present. 2. Connect the oscilloscope leads from tip to ground. Page 71 Telecommunications Industry Association TR41.9.1-10-05-002L 3. Repeat steps (1)(a) through (d). 4. Connect the oscilloscope leads from ring to ground. 5. Repeat steps (1)(a) through (d). 1.15.6 Alternative Method None suggested. 1.15.7 Suggested Test Data For Tip - Ring, Tip - Ground, and Ring - Ground: 1. Maximum peak AC voltage measured if less than 70 volts peak. 2. Maximum and duration if peak AC voltage is greater than 70 volts.. 1.15.8 Comments None. Page 72 Telecommunications Industry Association TR41.9.1-10-05-002L Page 73 Telecommunications Industry Association TR41.9.1-10-05-002L 1.16 Hazardous Voltage Limitations, E&M TIA-968-B, 5.1.15 1.16.1 Background E&M leads provide DC signaling between equipment units on the same premises. They have a limited signaling range and are commonly used in the PBX environment between tie trunk circuits and associated telephone company line signaling circuits, such as those used for long range DC signaling (DX) or single-frequency signaling (SF). TIA-968-B addresses two types of E&M lead interfaces: one using ground return, referred to as Type I and the other using metallic return, referred to as Type II. The "A" and "B" sides each refer to a specific portion of the E&M signaling circuit as shown in Figure 1.5 and 1.6 of TIA-968-B. The "A" side contains the E-lead detector and the "B" side contains the M-lead detector. Either side may be provided by the approved terminal equipment, but normally a PBX tie trunk circuit provides the "A" side. There may also be cases where the approved terminal equipment provides the "B" side. For example, a line concentrator that could be interposed either between a PBX tie trunk circuit and a telephone company line signaling circuit, or between two line signaling circuits at an intermediate location, would require both an "A" side and a "B" side. 1.16.2 Purpose To verify that the E&M circuitry provided by approved terminal equipment does not generate steady-state or transient conditions that can harm telephone company personnel or equipment. 1.16.3 Equipment 1. DC current meter SEL#19. 2. DC voltmeter SEL#22. 3. Digital sampling storage oscilloscope SEL#23. 4. Trace recording device SEL#31. 5. True rms AC voltmeter SEL#41. Note: Refer to subclause 5.5 for equipment details. Page 74 Telecommunications Industry Association TR41.9.1-10-05-002L 1.16.4 Equipment States Subject to Test E&M leads have two active states: idle (on-hook) and operated (off-hook). With either Type I or Type II, the E lead is open in the idle state and grounded in the operated state by a contact on the "B" side. Likewise, with Type I, the M lead is grounded in the idle state and connected to battery through a current limiting device in the operated state by contacts on the "A" side. With Type II, the M lead is open in the idle state and connected to battery through a similar current limiting device also by contacts on the "A" side. 1.16.5 Procedure Unless otherwise specified below, all tests should be made in the idle state. Lead designations are the same as in subclause 5.1.15 and subclause 5.1.15 of TIA-968-B. Requirements for specific cases should be selected from Table 8.2-1, as appropriate. The five types of tests listed in this table are referred to as: 1. DC current to ground. 2. Ground the lead through the current meter, and measure the resulting current. 3. AC voltage to ground. Connect AC voltmeter between designated lead and ground, and measure the voltage. 4. DC voltage to ground. Connect DC voltmeter across a 20 kilohm +/-10% resistor located between designated lead and ground, and measure the voltage. 5. Surge suppression. Examine a schematic of the E&M circuit, and determine if means are provided to limit the DC voltage (referenced to ground) to 60 V while providing a power dissipation of 0.5 W. Note: This is provided by Surge Suppression (SS) in Figure 1.5 of TIA-968-B. See Comment (1). 6. Contact Protection. Page 75 Telecommunications Industry Association TR41.9.1-10-05-002L Compliance can be verified either by examining a circuit diagram of the E&M circuit or by measuring voltages across contacts as shown in Figure 8.2-1. Verification is required only if the E-lead detector on the "A" side is inductive. Verify, by circuit examination, that contact protection is provided across the winding to limit: 1. the peak voltage to 300 V, 2. the rate of change of voltage to 1 volt per microsecond (V/s), and 3. the voltage level to 60 V or less after 10 ms (See Comment (2)). 6. Voltage measurements 1. Connect the EUT to the test circuit of Figure 8.2-1. 1. Open switch S1 and record the oscilloscope trace. 1.16.6 Alternative Methods None suggested. 1.16.7 Suggested Test Data 1. The tested lead, and as appropriate: 1. DC current to ground; 2. AC voltage to ground; 3. DC voltage to ground; 4. Verification of M lead surge suppression; 5. Verification of contact protection. 6. 2. Where compliance is verified by inspection, include a short discussion describing the means provided. Page 76 Telecommunications Industry Association TR41.9.1-10-05-002L 1.16.8 Comments 1. Traditionally, M-lead surge suppression is provided on the "A" side of the interface. In older circuits using mercury-wetted or wire-spring relay contacts it was a 1000-ohm resistor between the M lead and ground. A more energy efficient method is achieved by using a zener diode (typically with a breakdown voltage of 68 V) in series with the 1000ohm resistor. If dial pulsing is not required, the 1000-ohm resistor can be omitted. 2. The E-lead contact protection circuit is normally connected across the detector. The limits specified are based on the characteristics of contact protection commonly used in the industry. Contact protection is typically a series RC circuit. The value of C is chosen so that the voltage developed across it does not exceed 300 V. This requirement can be satisfied using the following relationship: where: C is the capacitance in microfarads (F) I is the current in A, through the inductive load when the contact opens L is the inductance of the load in H. The voltage rise limit of 1 volt per microsecond (V/s) is satisfied when: Other methods of transient suppression for inductive loads include placing a diode in series with a zener diode or a varistor across the inductor. 3. Refer to subclause 4.4.3 for the definition of non-hazardous voltage. Table 8.2-1 E&M Leads to be Tested Interface Type Type I B Type II Side of the Interface A A B Lead to be Tested E M E M E SG M SB E SG M SB 1 DC Current to Gnd X X X 2 AC Voltage to Gnd X X X X X X X X X X X X 3 DC Voltage to Gnd X X X X X X X X X X X X 4 Surge Suppression 5 Contact Protection X X Page 77 X X Telecommunications Industry Association TR41.9.1-10-05-002L Page 78 Telecommunications Industry Association TR41.9.1-10-05-002L Page 79 Telecommunications Industry Association TR41.9.1-10-05-002L Note: S1 consists of the contacts of a relay which are designed to be free of contact bounce, such as those provided in a mercury-wetted relay. Figure 8.2-1 E or M-Lead Contact Protection Page 80 Telecommunications Industry Association TR41.9.1-10-05-002L 1.17 Hazardous Voltage Limitations, OPS TIA-968-B, 5.1.16.5, 5.1.16.6 1.17.1 Background The Off Premises Station (OPS) function in CPE provides loop start line signaling similar to that normally provided by a CO line circuit. This means that it provides not only the battery necessary for talking and DC signaling but also the AC ringing voltage for signaling from the CPE to the station equipment. A network private line facility connects the OPS line circuit with the remote station equipment. Thus, there are two network interfaces, one at each end of the private line facility. Approved station equipment is used as the off premises station. The hazardous voltage requirements for OPS ports were written to protect network personnel. The AC voltage limit for ringing exceeds the combined AC/DC limit for non-hazardous voltages, but is to meet specific duration requirements to render it non-hazardous. 1.17.2 Purpose To verify that the OPS line interface complies with the specified AC and DC voltage limits. 1.17.3 Equipment 1. DC voltmeter SEL#22. 2. True rms AC voltmeter SEL#41. Note: Refer to subclause 5.5 for equipment details. 1.17.4 Equipment States Subject to Test 1. Idle open circuit. 2. Ringing open circuit. 1.17.5 Procedure 1. In the idle open circuit state, measure the DC voltage with the DC voltmeter connected between: 1. T(OPS) and R(OPS); 2. T(OPS) and ground; Page 81 Telecommunications Industry Association TR41.9.1-10-05-002L 3. R(OPS) and ground. (2) In the idle open circuit state, measure the extraneous AC voltage with the AC voltmeter connected between: 1. T(OPS) and R(OPS); 2. T(OPS) and ground; 3. R(OPS) and ground. 3. In the ringing open circuit state, confirm that the ringing signal is applied to the proper lead by measuring the AC voltage with the AC voltmeter connected between: 1. T(OPS) and ground; 2. R(OPS) and ground. 4. Perform tests specified in subclause 8.8 to verify compliance with ringing source requirements. 1.17.6 Alternative Methods None suggested. 1.17.7 Suggested Test Data 1. DC voltages during idle open circuit state: 1. T(OPS) and R(OPS); 2. T(OPS) and ground; 3. R(OPS) and ground 2. Extraneous AC voltages during idle open circuit state: 1. T(OPS) and R(OPS); Page 82 Telecommunications Industry Association TR41.9.1-10-05-002L 2. T(OPS) and ground; 3. R(OPS) and ground. 3. Ringing AC voltages during ringing open circuit state: 1. T(OPS) and ground; 2. R(OPS) and ground. 4. Verification of proper application of ringing. 5. Test data as specified in subclause 8.8.7. 1.17.8 Comments Test results that comply with the requirements of TIA-968-B, 5.1.16.5, 5.1.16.6 as tested here also satisfy the signal power requirements in TIA-968-B, 5.1.16. Refer to 4.4.3 for the definition of non-hazardous voltage source. Page 83 Telecommunications Industry Association TR41.9.1-10-05-002L Page 84 Telecommunications Industry Association TR41.9.1-10-05-002L 1.18 Hazardous Voltage Limitations, DID TIA-968-B, 5.1.17.3 1.18.1 Background The Direct Inward Dialing (DID) function in CPE provides some loop start line signaling similar to that normally provided to by a CO line circuit. Although it does not provide the AC ringing voltage like OPS, it does provide battery for DC signaling. The hazardous voltage requirements were written for DID to protect network personnel. 1.18.2 Purpose To verify that the DID interface complies with the specified DC voltage limits. 1.18.3 Equipment 1. DC voltmeter SEL#22. 2. True rms AC voltmeter SEL#41. Note: Refer to subclause 5.5 for equipment details. 1.18.4 Equipment States Subject to Test Idle open circuit. 1.18.5 Procedure 1. In the idle open circuit state, measure the DC voltage with the DC voltmeter connected between: 1. T and R; 2. T and ground; 3. R and ground. Page 85 Telecommunications Industry Association TR41.9.1-10-05-002L 2. In the idle open circuit state, measure the extraneous AC voltage with the AC voltmeter connected between: 1. T and R; 2. T and ground; 3. R and ground. 1.18.6 Alternative Methods None suggested. 1.18.7 Suggested Test Data 1. DC voltages during idle open circuit state: 1. T and R; 2. T and ground; 3. R and ground. 2. Extraneous AC voltages during idle open circuit state: 1. T and R; 2. T and ground; 3. R and ground. 1.18.8 Comments Refer to subclause 4.4 of TIA-968-B for the definition of non-hazardous voltage. Page 86 Telecommunications Industry Association TR41.9.1-10-05-002L 1.19 Hazardous Voltage Limitations, LADC TIA-968-B, 5.2.1.2 1.19.1 Background Local Area Data Channel (LADC) is a limited distance metallic facility provided by the telephone company for data transmission. It may be either a two-wire or four-wire nonloaded facility. Protection of these facilities consists of limiting the combined AC and DC current during normal operation to a value consistent with CO protective devices. Protection of network personnel is ensured by limiting the AC and DC voltages at the network interfaces to levels permitted for non-hazardous voltage sources as defined in TIA-968-B subclause 4.4.3. If ringing is used, it is to meet the requirements of TIA-968-B subclause 4.4.4 (see subclause 8.8 for test procedures) 1.19.2 Purpose To verify that the currents and voltages present at the interface are not hazardous to personnel or equipment. 1.19.3 Equipment 1. DC voltmeter SEL#22. 2. Digital sampling storage oscilloscope SEL#23. 3. True rms current meter SEL#42. Note: Refer to subclause 5.5 for equipment details. 1.19.4 Equipment States Subject to Test All operating states, except ringing. 1.19.5 Procedure WARNING! ADEQUATE SAFETY PRECAUTIONS SHOULD BE OBSERVED! 1. Place EUT in first operating state. 2. Connect current meter between T and R leads of the EUT, and measure combined AC and DC short circuit current. Page 87 Telecommunications Industry Association TR41.9.1-10-05-002L 3. Repeat Step (2) with current meter between T and ground and between R and ground. 4. Repeat Step (1) through Step (3) for the T1 and R1 pair of the EUT if testing a four-wire interface. 5. Connect DC voltmeter between T and ground, and measure voltage. 6. Repeat Step (5) with voltmeter between R and ground. 7. Repeat Step (5) and Step (6) for the T1 and R1 pair if testing a four-wire interface. 8. Connect oscilloscope between T lead and ground, and measure AC peak and combined AC peak and DC voltages with other network leads unterminated. 9. Repeat Step (8) with oscilloscope between R and ground. 10. Repeat Step (8) and Step (9) for the T1 and R1 pair if testing a four-wire interface. 11. Repeat Step (8) through Step (10) for AC peak voltage only with other network leads individually terminated to ground. 12. Repeat Step (2) through Step (11) for other modes of operation. 1.19.6 Alternative Methods None suggested. 1.19.7 Suggested Test Data 1. Current between conductor pairs (AC and DC). 2. Current between each conductor and ground (AC and DC). 3. DC voltages to ground for each conductor. 4. AC voltages to ground for each conductor (other conductors unterminated). 5. AC voltages to ground for each conductor (other conductors terminated). 6. AC plus DC (total) voltages to ground for each conductor (other conductors unterminated). Page 88 Telecommunications Industry Association TR41.9.1-10-05-002L 1.19.8 Comments Refer to TIA-968-B subclause 4.4.3 for the definition of non-hazardous voltage. Page 89 Telecommunications Industry Association TR41.9.1-10-05-002L 1.20 Ringdown Voiceband Private Line and Metallic Channel Interface TIA-968-B, 5.1.17 1.20.1 Background Voiceband private lines referred to in this requirement provide a dedicated voice channel with signaling capability between two or more customer premises. The facility may be either two-wire or four-wire and is usually referred to by the type of signaling between locations (points). Thus, there are two-point and multipoint private lines. Two-way ringdown, or simply "ringdown," is one of the signaling methods used for such private lines. The signaling range can be extended by converting to an inband signaling tone referred to as single-frequency signaling. A metallic facility referred to in this requirement is simply a pair or two pairs of wires with no restriction on the type of signaling that can be used. Two-way ringdown relies solely on the application of ringing voltage at either end of the private line for alerting the other end. Battery is not required for voice transmission, but DC monitoring voltage, as defined in subclause 8.8.1, may be present. The short circuit limit for both ringdown and metallic private lines is consistent with the maximum current capabilities of most load coils that may be on the line. 1.20.2 Purpose To verify that voltages and currents appearing at ringdown and metallic private line interfaces are not hazardous to personnel or equipment. 1.20.3 Equipment 1. DC current meter SEL#19. 2. DC voltmeter SEL#22. Note: Refer to subclause 5.5 for equipment details. 1.20.4 Equipment States Subject to Test 1. Idle. 2. Talking. 3. Signaling. Page 90 Telecommunications Industry Association TR41.9.1-10-05-002L 1.20.5 Procedure WARNING! ADEQUATE SAFETY PRECAUTIONS SHOULD BE OBSERVED! Inspect appropriate circuit diagrams to verify the following: 1. Ringing voltage is applied to the R lead with the T lead grounded for two-wire interfaces; 2. Ringing voltage is simplexed on the T and R leads, and ground is simplexed on the T1 and R1 leads for four-wire interfaces. 3. Perform tests specified in subclause 8.8.5 to verify compliance with ringing source requirements in the signaling state. 4. Place EUT in the idle state. 5. Connect DC voltmeter between T lead and ground of the EUT, and measure the voltage, noting polarity. 6. Repeat Step (4) for R lead. 7. Repeat Step (4) and Step (5) for T1 and R1 leads of the EUT if testing a four-wire interface. 8. Repeat Step (3) through Step (6) with EUT in the talking state. 9. Place EUT in idle state. 10. Connect current meter between T and R leads, and measure short circuit current. 11. Repeat Step (9) between T lead and ground and between R lead and ground. 12. Repeat Step (9) for T1 and R1 leads if testing a four-wire interface. 13. Repeat Step (9) through Step (11) for talking state. 1.20.6 Alternative Methods None suggested. Page 91 Telecommunications Industry Association TR41.9.1-10-05-002L 1.20.7 Suggested Test Data Brief written analysis of observed ringing circuit arrangements verifying the following: (i) ringing is used for alerting only, (ii) ringing voltage is applied to R lead, and (iii) ringing voltage is simplexed on T and R leads. 1. DC voltages during idle and talking states: 1. T to ground; 2. R to ground; 3. T1 to ground; 4. R1 to ground. 2. DC current during idle and talking states: 1. T to R; 2. T to ground; 3. R to ground; 4. T1 to R1; 5. T1 to ground; 6. R1 to ground. 1.20.8 Comments Refer to TIA-968-B subclause 4.4.3 for the definition of non-hazardous voltage. Page 92 Telecommunications Industry Association TR41.9.1-10-05-002L 1.21 Physical Separation of Leads TIA-968-B, 4.3.2 1.21.1 Background Physical separation of leads within approved terminal equipment and protective circuitry is part of the overall requirement that hazardous voltages can’t appear at the network interface. 1.21.2 Purpose To verify that network interface leads are adequately separated from power leads and from hazardous voltage leads that connect to non-approved equipment. 1.21.3 Equipment 1. DC voltmeter SEL# 22 (if required). 2. True rms AC voltmeter SEL#41 (if required). Note: Refer to subclause 5.5 for equipment details. 1.21.4 Equipment States Subject to Test Powered EUT connected to non-approved equipment, if non-approved equipment provides a source of hazardous voltage. 1.21.5 Procedure WARNING! ADEQUATE SAFETY PRECAUTIONS SHOULD BE OBSERVED! 1. Inspect schematic and/or wiring diagram to identify leads for connection to the network interface, including telephone connections, auxiliary leads, and E&M leads. Also identify power leads and leads to non-approved equipment that by the definition provided in TIA968-B subclause 4.4.3, carry hazardous voltage. Note: Leads in this procedure refer to any type of metallic connection. Page 93 Telecommunications Industry Association TR41.9.1-10-05-002L 2. Inspect the equipment to verify that leads for connection to the network are adequately separated from power leads and from leads to non-approved equipment carrying hazardous voltage as follows: Leads for connection to the network are not routed in the same cable as, or use the same connector as, leads or metallic paths making power connections. Leads for connection to the network are not routed in the same cable as, or use adjacent pins on the same connector as, leads to non–approved equipment where those leads carry hazardous voltage. 3. Use the AC or DC voltmeter as required to confirm that the affected leads to nonapproved equipment are indeed hazardous. 1.21.6 Alternative Methods None suggested. 1.21.7 Suggested Test Data 1. Provide a short discussion that summarizes observation of: 2. Lead separations. 3. Voltages on leads to non-approved equipment. 4. Lead routing in cables. 5. Pin assignments in connectors with leads for connection to both the network interface and non-approved equipment. 1.21.8 Comments The identification of non-hazardous voltage leads to non-approved equipment may be verified by inspecting the circuit diagram or actual measurement as appropriate. Page 94 Telecommunications Industry Association TR41.9.1-10-05-002L 1.22 Ringing Sources TIA-968-B, 4.3.3 1.22.1 Background A ringing source is considered to be non-hazardous to telephone company personnel if it meets the current, voltage, and duration requirements in subclause 4.3.3 of TIA-968-B. The requirements take into account wet hands-to-feet contact and wet hand-to-hand contact. Current values up to 100 mA peak-to-peak are permitted for a period of 5 seconds after which a silent (no ringing) interval of at least 1 second is required to permit "let-go." During the first second of a five-second ringing interval, current values up to 600 mA are permitted, based upon the time required to trip (stop) the ringing after contact with the 500-ohm and 1500-ohm resistances. In general, the current limit decreases from 600 mA peak-to-peak to 100 mA peak-to-peak, with increasing trip times of up to 1 second, as depicted in Figure 4.4 of TIA-968-B. A monitoring voltage may be used in place of, or in addition to, the trip device depending on the values of current through 500-ohm and 1500-ohm resistances. A trip device may be sensitive to either DC or AC current or both, but in any case the ringing source is disconnected when the AC current reaches a predetermined value. Monitoring voltage is a DC voltage that is applied by the EUT during the one-second silent interval to warn people contacting the pair that a ringing source may be connected at any time. It is limited to a range of 19 V (the lower limit of a 24-volt battery) to 56.5 V (the upper limit of a 48-volt battery). The 200 V peak-to-ground limit allows for a maximum DC component of 50 V when used in conjunction with the maximum 300 V peak-topeak limit. 1.22.2 Purpose To verify the EUT ringing source characteristics. 1.22.3 Equipment 1. Digital sampling storage oscilloscope SEL#23. 2. Frequency counter SEL#26. Note: Refer to subclause 5.5 for equipment details. 1.22.4 Equipment States Subject to Test Page 95 Telecommunications Industry Association TR41.9.1-10-05-002L There are two operating states: ringing and non-ringing. All measurements except for monitoring voltage are made in the ringing state. Monitoring voltage, when required, is measured in both states. 1.22.5 Procedure WARNING! ADEQUATE SAFETY PRECAUTIONS SHOULD BE OBSERVED! 1. Connect the frequency counter to the T and R leads of the EUT, and measure the frequency of the ringing voltage. 2. If the EUT is a four-wire device, connect the frequency counter to the T and R leads of the EUT tied together and to the T1 and R1 leads of the EUT also tied together, and measure the frequency of the ringing voltage. 3. Connect the EUT to the test circuit of Figure 8.8-1 if the EUT is a two-wire device, or to the test circuit of Figure 8.8-2 if the EUT is a four-wire device. Note: A 10X probe should be used. 4. Set switch S1 to position "A" and measure: 1. peak-to-peak ringing voltage; 2. peak-to-ground ringing voltage; 3. ringing time interval; 4. non-ringing time interval. 5. Set switch S1 to position "B" and initiate ringing. 6. Measure and record the peak-to-peak voltage. 7. If ringing is tripped, measure duration of applied ringing. 8. Convert the voltage recorded in Step (6) to peak-to-peak current in milliamperes. Page 96 Telecommunications Industry Association TR41.9.1-10-05-002L 9. Set switch S1 to position "C" and repeat Step (5) through Step (8). 10. Refer to the table in Figure 8.8-3 to determine compliance with ringing voltage and the need for a tripping device and a monitoring voltage. Note: The peak-to-peak current and the time duration of the current measured through the 500-ohm and 1500ohm resistors in Step (5) through Step (9) are used in this determination. If a monitoring voltage is required, connect the oscilloscope (DC coupled) using the 10X probe and measure the DC voltage present during the ringing and non-ringing states. 1.22.6 Alternative Methods None suggested. 1.22.7 Suggested Test Data 1. Ringing frequency. 2. Ringing voltages, peak-to-peak and peak-to-ground. 3. Duration of the ringing interval. 4. Duration of the non-ringing interval. 5. Current through 500-ohm resistance and trip time, if required. 6. Current through 1500-ohm resistance and trip time, if required. 7. Monitor voltage, if required. 1.22.8 Comments Refer to TIA-968-B subclause 4.4.3 for the definition of non-hazardous voltage. Page 97 Telecommunications Industry Association TR41.9.1-10-05-002L Page 98 Telecommunications Industry Association TR41.9.1-10-05-002L Note: A 10X probe is normally used to obtain the reading. The input Impedance of the probe should be equal to or greater than 1 megohm. Figure 8.8-1 Ringing Sources, Two-Wire Note: A 10X probe is normally used to obtain the reading. The input impedance of the probe should be equal to or greater than 1 megohm. Figure 8.8-2 Ringing Sources, Four-Wire Page 99 Telecommunications Industry Association Page 100 TR41.9.1-10-05-002L Telecommunications Industry Association 2 Figure 8.8-3 Ringing Protection Page 101 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.23 Intentional Operational Paths to Ground TIA-968-B, 4.3.5.1 1.23.1 Background Products which have intentional DC current paths to ground will not comply with the leakage current limitations of TIA-968-B, 4.2. To ensure that these network connections do not pose a hazard to network personnel, a ground continuity test is performed from leakage exempted network points to earth ground connections. The Tip Ground state of a central office implemented telephone is a momentary state (200 to 1200 ms). It occurs when (1) a coin is in the hopper and (2) the network is making an initial coin deposit test, a local coin overtime deposit test, or stuck coin test, and when the network is trying to collect or return a coin. When the network performs those operations, it opens the ring conductor and places a DC voltage (typically -48, +48, -130, or +130 Vdc) on the tip conductor. The central office implemented telephone has a reset electromagnet in series with a coin relay (900 to 2000 ohms) between the tip conductor at the network interface and the earth grounding connection. This test is performed on the grounded side of the coin relay. 1.23.2 Purpose To verify the ground continuity between grounded telecommunications points and EUT earth grounding connections. 1.23.3 Equipment 1. Variable DC current source SEL#17. 2. DC current meter SEL#19. 3. DC volt meter SEL#22. Note: Refer to subclause 5.5 for equipment details. 1.23.4 Equipment States Subject to Test Test all telephone connections including tip, ring, tip1, ring1, E&M leads, and auxiliary leads to earth grounding connections. In the event that there is a circuit or component between the Page 102 Telecommunications Industry Association TR41.9.1-10-05-002L network demarcation point and ground, the test is to be performed from the grounded side of the component or circuit. 1.23.5 Procedure WARNING! ADEQUATE SAFETY PRECAUTIONS SHOULD BE OBSERVED! 1. Connect the EUT to the test circuit of Figure 8.9-1. 2. Select the appropriate EUT test points. 3. Gradually increase the current from zero to 1 A, then maintain the 1 A current for one minute. 4. Monitor the voltage on the DC voltmeter. Verify that the voltage does not exceed 0.1 Volt at any time. 1.23.6 Alternative Methods None suggested. 1.23.7 Suggested Test Data 1. List of test points. 2. Maximum DC voltage measured during tests. 1.23.8 Comments Refer to subclause 4.4 of TIA-968-B for the definition of a non-hazardous voltage source. Page 103 Telecommunications Industry Association Page 104 TR41.9.1-10-05-002L Telecommunications Industry Association Note A - See 7.3.1.3 Figure 8.9-1 Intentional Operational Paths to ground Page 105 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.24 Intentional Protective Paths to Ground TIA-968-B, 4.3.4.2 1.24.1 Background Products which have intentional DC conducting paths to ground for protection purposes may fail the leakage current limitations of TIA-968-B, 4.2. The leakage current test of clause 7 allows these paths to be opened (or component removed). To ensure that these network connections do not present a hazard to network personnel, the components are re-installed, and a leakage current test is performed at a lower voltage representative of an AC power fault. 1.24.2 Purpose To verify that protective devices do not provide a path for harmful leakage currents at AC power voltages. 1.24.3 Equipment 1. Variable AC voltage source SEL#43 (for TE) or SEL#44 (for PC). 2. AC current meter SEL#42. Note: Refer to subclause 5.5 for equipment details. 1.24.4 Equipment States Subject to Test Simplexed telephone connections, including tip and ring, tip1, ring1, E&M leads, and auxiliary leads. 1.24.5 Procedure WARNING! ADEQUATE SAFETY PRECAUTIONS SHOULD BE OBSERVED! 1. Re-install any protective devices removed for the leakage tests (See clause 7). 2. Connect the EUT to the test circuit of Figure 8.10-1. Page 106 Telecommunications Industry Association TR41.9.1-10-05-002L 3. Select the appropriate EUT test points. 4. Gradually increase the voltage from zero to 120 VRMS (for TE) or 300 VRMS (for PC). Maintain the maximum voltage for one minute. 5. Monitor the current through the AC ammeter. Verify that the current does not exceed 10 mA peak at any time. 1.24.6 Alternative Methods None suggested. 1.24.7 Suggested Test Data 1. List of leads tested. 2. List of maximum current measured for each combination. 1.24.8 Comments 1. This test is to be applied to leads excluded from the requirements of TIA-968-B, 4.3.4.1 that contain only intentional protective paths to ground. An EUT which has both intentional operational and intentional protective paths to ground needs to meet only the requirements of TIA-968-B, 4.3.4.1 referred to in subclause 8.9 of this Document Refer to TIA-968-B, 4.4.3 for the definition of a non-hazardous voltage source and TIA-968-B, 4.3 Note (1). Figure 8.10-1 Intentional Protective Paths to Ground Page 107 Telecommunications Industry Association Page 108 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L SIGNAL POWER LIMITATIONS TIA-968-B, 4.4.1.1 1.25 Voiceband Signal Power – Not Network Control signals TIA-968-B, 5.2.1 1.25.1 Background There are seven different service-specific power criteria covered for analog voiceband internal signal sources. The services include connections to: - PSTN; - foreign exchange; - tie trunks; - off-premises stations; - test equipment; private lines using ringdown or inband signaling. Maximum voiceband signal power criteria are based on multichannel analog carrier overload characteristics and intermodulation distortion limits. Each specific type of service has a different maximum limit which takes into account, among other factors: - the multichannel carrier overload limit; - the multichannel carrier activity factor per channel; - the average input signal power per channel; - the maximum input signal power per channel; - the local exchange facility attenuation characteristic; the type of signal being transmitted. These restrictions ensure that equipment will not apply a signal to the multichannel carrier in excess of the maximum level permitted per channel if it encounters a low loss loop facility. The signal power limit specified for voiceband signals applies to all internal signals other than livevoice. Live-voice limits are not specified because normal statistical variations among talkers will tend to produce appropriate average talker power per channel at the multichannel carrier interface. Also, loud talkers will lower their talking levels because of excessive side tone levels or if requested by the other connected parties, thus providing a form of self-correction for excessive live-voice signal power. Such factors and controls do not apply for other than livevoice signals, and thus the limitations apply. The 3-second averaging time approximates the period necessary for a listener to perceive interference as intelligible crosstalk. Page 109 Telecommunications Industry Association Page 110 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.25.2 Purpose To verify that the voiceband signal power from internal sources, other than live-voice signals, transmitted to the PSTN, are properly limited. 1.25.3 Equipment (1) Applicable loop simulator SEL#4. (2) Bandpass filter SEL#5 (3) DC current meter SEL#19. (4) True rms AC voltmeter SEL#40. (5) Signal Analyzer (FFT) SEL#56 Note: Refer to subclause 5.5 for equipment details. 1.25.4 Equipment States Subject to Test Test any off-hook state of the EUT which transmits signals to the network which are not intended for network control. For an EUT that does not normally transmit signals toward the network interface in the off-hook state, the idle (nontransmitting) state is to be tested. For data signals, the EUT is tested in accordance with subclause 8.4. 1.25.5 Procedure (1) Connect the EUT to the applicable test circuit of Figure 9.1-1 through Figure 9.1-3 using the 200 Hz to 4000 Hz bandpass filter and voltmeter. (2) Place the EUT in the desired off-hook state and transmit a desired signal from internal sources at maximum power. Page 111 Telecommunications Industry Association TR41.9.1-10-05-002L (3) Measure and record the maximum signal power level in dBm at minimum and maximum loop currents attainable with the loop simulator, if applicable. (4) Repeat step (2) and step (3) for other internal signals. (5) Repeat step (2) through step (4) for other operating states, if applicable. 1.25.6 Alternative Methods (1) Connect the EUT to the test circuit of Figure 9.1-1 through Figure 9.1-3 and replace the bandpass filter and true rms AC voltmeter with the signal analyzer SEL#56. (2) Set the signal analyzer to measure the following: 1. Signal level in dBm, 600 ohms. 2. Averaging over 3 second. 3. Band pass power in the frequency range of 200 Hz to 4 kHz band. Note: If the Signal Analyzer does not provide a balanced input an isolation transformer may be used. (3) Place the EUT in the desired off-hook state and transmit a desired signal from internal sources at maximum power. (4) Measure and record the maximum signal power level in dBm at minimum and maximum loop currents attainable with the loop simulator, if applicable. (5) Repeat step (2) and step (3) for other internal signals. (6) Repeat step (2) through step (4) for other operating states, if applicable. 1.25.7 Suggested Test Data (1) Operating states. (2) Signals measured. (3) Signal power levels in dBm. Page 112 Telecommunications Industry Association TR41.9.1-10-05-002L (4) Loop conditions for maximum signal power if appropriate. 1.25.8 Comments (1) All references to dBm are with respect to 600 ohms. (2) A sound attenuating cover should be placed on any acoustic pick-up device to minimize the effects of ambient noise. (3) As mentioned in subclause 9.1.1, the level of live-voice signals are not regulated under 47 CFR Part 68. Recorded or synthesized signals are not live-voice signals and, as such, are regulated by 47 CFR Part 68. Typically there are three types of signals to consider: (a) Electrical signals recorded at a given network interface. The test signal used is to be the one that results in the highest output signal level when played back to the line. The level of the output signal measured should not exceed the specified limit for that class of service (e.g., -9 dBm for PSTN ports). 2. Acoustic signals recorded locally. These signals may be recorded by means of an integrated or external microphone. The test signal is to be recorded with an acoustic input signal level that results in the highest output signal level when played back to the line. The level of the output signal measured should not exceed the specified limit for that class of service (e.g., -9 dBm for PSTN ports). 3. Signals recorded elsewhere (e.g. electronic “wave” files contained in voice servers). If the recorded signal is not under the control of the EUT manufacturer (e.g. “wave” files from the Internet) then the EUT is to limit the output signal level to not exceed the specified limit for that class of service (e.g., -9 dBm for PSTN ports). The test signal used is to be the one that results in the highest output signal level when played back to the line. If the recorded signal is under the control of the EUT manufacturer (directly or indirectly) then the EUT is to be tested with these recorded signals and the output signal level is not to exceed the specified limit for that class of service (e.g., -9 dBm for PSTN ports). The test signal used may depend on the EUT. Possible signals include, but are not limited to, a 1 kHz tone, white noise, or a modulated multifrequency signal. The level of this signal should be taken over a 3 second average. Page 113 Telecommunications Industry Association TR41.9.1-10-05-002L (4) A voltmeter with an averaging time less than 3 seconds may be used. In this case correction factors should be applied to the measured value based on the duty cycle of the signals. (5) The insertion loss of the bandpass filters used is to be taken into account. (6) The insertion loss of any balanced to unbalanced transformer used is to be taken into account. 1. Select the appropriate loop simulator for the interface of the EUT. 2. Connect the bandpass filter across R1 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. Figure 9.1-1. Voiceband Signal Power, Two-Wire Page 114 Telecommunications Industry Association Page 115 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1. Select the appropriate loop simulator for the interface of the EUT. 2. Connect the bandpass filter across R1 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. Figure 9.1-2. Voiceband Signal Power, Four-Wire Note: The condition shown is for a four-wire interface; for two-wire interface, the T1 and R1 is not present. Figure 9.1-3. Voiceband Signal Power, E&M Tie Page 116 Telecommunications Industry Association TR41.9.1-10-05-002L 1.26 Voiceband Signal Power - Network Control Signals TIA-968-B, 5.1.3 1.26.1 Background The signal power limitations for network control signals minimize interference to other users of the PSTN. These limitations are based on the cable wire-pair crosstalk characteristics in the local exchange network and the interfering effect that such signals cause to third party users of network services throughout the cable-wire facilities. Multichannel carrier input overload is not a factor in this situation since network control signals terminate in the local CO. At the present time, the effect of DTMF tones is disregarded when they are generated by manual operation of a telephone keypad or are generated automatically with no more than 40 DTMF digits per keystroke and are used for purposes of transmitting information after the establishment of an end-to-end connection. The subscriber line carrier system's susceptibility is not a factor either since it operates above the voiceband. Under certain conditions, central office implemented telephones generate coin deposit signals in response to coins being deposited. These signals are a discrete number of bursts of a twofrequency tone and are intended to be detected by network elements. Excessive coin deposit signals may harm the network. Therefore, they are subject to clause 5.1.3 of TIA-968-B although they are not specifically mentioned by name. 1.26.2 Purpose To verify that the level of any signal primarily intended for network control is properly limited. 1.26.3 Equipment (1) Applicable loop simulator SEL#4. (2) Bandpass filter SEL#5. (3) DC current meter SEL#19. (4) True rms AC voltmeter SEL#40. Note: Refer to subclause 5.5 for equipment details. Page 117 Telecommunications Industry Association TR41.9.1-10-05-002L 1.26.4 Equipment States Subject to Test Test any off-hook states of the EUT which transmit to the network signals primarily intended for network control. 1.26.5 Procedure (1) Connect the EUT to the appropriate test circuit of Figure 9.21 or Figure 9.2-2 using the bandpass filter and voltmeter. (2) Set the voltmeter to measure the signal level in dBm. (3) Place the EUT in the off-hook state and transmit a desired network control signal. (4) and record the maximum signal power level in dBm at minimum and maximum loop currents attainable with the loop simulator, if applicable. (5) Repeat step (3) and step (4) for other network control signals, if applicable (e.g. other DTMF digits, MF digits or coin deposit signals). (6) Repeat step (3) and step (4) for other Page 118 Telecommunications Industry Association TR41.9.1-10-05-002L operating states, if applicable. 1.26.6 Alternative Methods (1) Connect the EUT to the test circuit of Figure 9.2-1 through Figure 9.2-2 and replace the bandpass filter and true rms AC voltmeter with a signal analyzer (SEL 56). (2) Set the signal analyzer to measure the following: (a) Signal level in dBm, 600 ohms. (b) Averaging over 3 second. (c) Band pass power in the frequency range of 200 Hz to 4 kHz band. Note: Signal Analyzer should provide a balanced input, or an isolation transformer may be used. (3) Place the EUT in the desired off-hook state and transmit a desired Network Control signal. (4) Measure and record the maximum signal power level in dBm at minimum and maximum loop currents attainable with the loop simulator, if applicable. (5) Repeat step (2) through step (4) for other network control signals, if applicable (e.g. other DTMF digits, MF digits or coin deposit signals). (6) Repeat step (2) through step (4) for other operating states, if applicable. 1.26.7 Suggested Test Data (1) Operating states. (2) Network Control Signal. (3) Signal power levels in dBm. (4) Loop conditions for maximum signal power, if appropriate. Page 119 Telecommunications Industry Association TR41.9.1-10-05-002L 1.26.8 Comments (1) All references to dBm are with respect to 600 ohms. (2) For EUT using manual DTMF signaling, the signal level should be measured for each digit and the one having the maximum power should be reported. (3) For EUT using manual DTMF signaling, a duty cycle of 40% is assumed. Thus reduce the measured level by 4dB. (4) For EUT using automatic DTMF signaling, the sequence of numbers should use all digits and be of maximum address length. (5) No measurements are required for DC pulse dialing. (6) A voltmeter with an averaging time less than 3 seconds may be used. In this case correction factors should be applied to the measured signal power based on the duty cycle. (7) Insertion loss of bandpass filter should be taken into account. 1. Select the appropriate loop simulator for the interface of the EUT. 2. Connect the bandpass filter across R1 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. Figure 9.2-1. Network Control Signal Power, Two-Wire Page 120 Telecommunications Industry Association Page 121 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1. Select the appropriate loop simulator for the interface of the EUT. 2. Connect the bandpass filter across R1 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. Figure 9.2-2. Network Control Signal Power, Four-Wire Page 122 Telecommunications Industry Association Page 123 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.27 Through-Transmission Equipment – DC Conditions for On-Premises TIA968-B, 5.1.5.1 1.27.1 Background Through-transmission equipment may provide DC for powering attached equipment. The attached equipment would be approved separately. To ensure compliance with signal power limits of TIA-968-B, the DC conditions provided to the attached equipment are required to fall within the range of conditions it would normally encounter if connected directly to the PSTN. When checking for compliance take the range of resistances presented by the attached equipment and the wiring that may be used to connect it into account. The maximum open circuit voltage provided by the loop simulator circuit shown in Figure 1.1 of TIA-968-B is 56.5 V. The maximum short circuit current is 141.25 mA, but 140 mA is used for this value in other places (e.g., see 4.5.2.7.2.2 of TIA-968-B). With an allowance of up to 400 ohms for the resistance of the attached equipment, the minimum current that will flow is 19.86 mA, but 20 mA is used for this value in other places (e.g., see 4.5.2.7.2.3 of TIA-968-B). The minimum current test condition is based on the criteria in the network interface standard T1.401. It allows a total resistance of 430 ohms for the customer installation, which consists of 400 ohms for the terminal equipment plus an allowance of 30 ohms for wiring and series devices between the terminal equipment and the network interface. If the EUT is designed to provide support for an external resistance greater than 430 ohms, it should be tested with that external resistance. 1.27.2 Purpose To verify that the DC conditions provided by the EUT meet the limits for the loop conditions that terminal equipment expects to encounter. 1.27.3 Equipment 1. DC voltmeter SEL#22. 2. DC current meter SEL#19. Note: Refer to subclause 5.5 for equipment details. Page 124 Telecommunications Industry Association TR41.9.1-10-05-002L 1.27.4 Equipment States Subject to Test Idle and Active state. 1.27.5 Procedure (1) Configure the EUT for normal operation. (2) Measure and record the open circuit voltage provided for powering the attached equipment. (3) Connect the EUT to the test circuit of Figure 9.3-1. (4) Adjust RL to 0 ohms, creating a short circuit across the through-transmission port of the EUT; measure and record the current that flows. (5) Adjust RL to 430 ohms or to the maximum external resistance supported by the EUT, if greater; measure and record the current that flows. 1.27.6 Alternative Methods None suggested. 1.27.7 Suggested Test Data (1) The open circuit voltage. (2) Short circuit current. (3) Maximum external resistance supported by the EUT if greater than 430 ohms. (4) Current at 430 ohms or at the maximum external resistance supported by the EUT, if greater than 430 ohms. 1.27.8 Comments If the test current meter does not incorporate internal fuse protection, a fuse should be added to the test circuit. The purpose of this fuse is to Page 125 Telecommunications Industry Association TR41.9.1-10-05-002L protect the test instrument if the DC source of the EUT through-path does not have adequate current limiting. Figure 9.3-1. DC Conditions for Through Transmission Page 126 Telecommunications Industry Association TR41.9.1-10-05-002L 1.28 Through-Transmission Equipment – Data TIA-968-B 5.1.5.2 1.28.1 9.4.1 Background EUTs with through-transmission paths that may be connected to data equipment is not to use the fixed loss loop or programmed data jack configurations unless they are approved in accordance with Section 4.4.2.2 of TIA-968-B. The rule restricts the use of the fixed loss loop and programmed data jack configurations. These jack configurations are to be used only on equipment specifically designed for data signals with power levels that comply with Section 4.4.2.2 of TIA-968-B. 1.28.2 9.4.2 Purpose To verify that the EUT or protective circuit is not equipped with the universal or programmed data jack configurations. 1.28.3 9.4.3 Equipment Schematics, and/or installation manuals. 1.28.4 9.4.4 Equipment States Subject to Test Not applicable. 1.28.5 9.4.5 Procedure Inspect the EUT, its schematics, and/or installation manual. Verify that the equipment is not equipped with either the universal or programmed data jack configuration. 1.28.6 9.4.6 Alternative Methods None suggested. 1.28.7 9.4.7 Suggested Test Data Page 127 Telecommunications Industry Association TR41.9.1-10-05-002L Statement that the equipment is not equipped with the universal of programmed data jack features. 1.28.8 9.4.8 Comments None. Page 128 Telecommunications Industry Association Page 129 TR41.9.1-10-05-002L Telecommunications Industry Association Page 130 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.29 Voiceband Signal Power - Data TIA-968-B, 4.4.2.2 1.29.1 Background The fixed loss loop, programmed and permissive jack configuration for approved data equipment with through-transmission paths permit users to operate their data equipment at maximum usable signal power in the PSTN. In the fixed loss loop and programmed jack configurations, the telephone company controls the loss. The signal power level for a permissive jack configuration is based upon a non-adjustable level that is equivalent to other than live-voice signal power levels. 1.29.2 Purpose To verify that the data signal power level transmitted to the PSTN is properly limited. 1.29.3 Equipment (1) Applicable loop simulator SEL# 4. (2) Bandpass filter SEL#5. (3) DC current meter SEL#19. (4) True rms AC voltmeter SEL#40. Note: Refer to subclause 5.5 for equipment details. 1.29.4 Equipment States Subject To Test Any off-hook state in which data is transmitted to the PSTN. 1.29.5 Procedure (1) Connect the EUT to the test circuit of Figure 9.5-1 using one of the EUT's specified jack configurations and using the bandpass filter and voltmeter. (2) Set the voltmeter to measure the signal level in dBm. Page 131 Telecommunications Industry Association TR41.9.1-10-05-002L (3) Place the EUT in the off-hook state and cause it to transmit a desired data signal. (4) Measure and record the maximum signal power level in dBm at minimum and maximum loop currents attainable with the loop simulator, if applicable. (5) Repeat step (3) and step (4) for the other data signals, if applicable. (6) Repeat step (3) and step (4) for the other operating states, if applicable. (7) Repeat step (3) and step (4) for other specified jack configurations, if applicable. Note: If the EUT is equipped with a programmable jack configuration, perform step (1) through step (5) for all specified values of the programming resistor, RP. 1.29.6 Alternative Methods (1) Connect the EUT to the test circuit of Figure 9.5-1 and replace the bandpass filter and true rms AC voltmeter with a signal analyzer (SEL XX). (2) Set the signal analyzer to measure the following: 1. Signal level in dBm, 600 ohms. 2. Averaging over 3 second. 3. Band pass power in the frequency range of 200 Hz to 4 kHz band. Note: Signal Analyzer should provide a balanced input, or an isolation transformer may be used. (3) Place the EUT in the desired off-hook state and transmit a desired data signal. (4) Measure and record the maximum signal power level in dBm at minimum and maximum loop currents attainable with the loop simulator, if applicable. (5) Repeat step (2) through step (4) for other data signals, if applicable. (6) Repeat step (2) through step (4) for other operating states, if applicable. (7) Repeat step (2) through step (4) for other specified jack configurations, if applicable. Page 132 Telecommunications Industry Association Page 133 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.29.7 Suggested Test Data (1) Jack configurations. (2) Data signals. (3) Operating states. (4) Signal power levels in dBm. (5) Loop conditions for maximum signal power, if appropriate. 1.29.8 Comments (1) All references to dBm are with respect to 600 ohms. (2) The insertion loss of bandpass filter should be taken into account. (3) For network control signals, see subclause 8.2. Page 134 Telecommunications Industry Association Page 135 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1. Refer to the figures of clause 1 of TIA-968-B. 2. Connect the bandpass filter across R1 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 4. For programmed data equipment, measurements should be made with the value of the programming resistor (RP) set for each of the following value: short circuit, 150 ohms, 336 ohms, 569 ohms, 866 ohms, 1240 ohms, 1780 ohms, 2520 ohms, 3610 ohms, 5490 ohms, 9200 ohms, 19800 ohms, and open circuit. Figure 9.5-1. Voiceband Signal Power, Data, TE Page 136 Telecommunications Industry Association TR41.9.1-10-05-002L 1.30 Through-Transmission – Port to Port Amplification TIA-968-B, 4.7.2, 4.7.3 1.30.1 Background Terminal equipment with through transmission provisions between network ports is required to limit the net amplification between ports in accordance with the matrix shown in TIA-968-B subclause 4.7.2, 4.7.3. The values given in the matrix ensure that the maximum permissible signal power levels at the network interface are not exceeded for any through path. In the case of digital port connections, the net amplification refers to the analog equivalent level. When 1.544 Mb/s connections are involved for both ports in question, then the through gain applies for each of the subrate channels when converted to analog through a zero-level decoder. 1.30.2 Purpose To verify that the through-transmission connections of the EUT do not provide gain in excess of that permitted in the matrix. 1.30.3 Equipment 1. Applicable loop simulator SEL#4. 2. Bandpass filter SEL#14. 3. Multiplexer/demultiplexer with zero level encoder/decoder SEL#32. 4. True rms AC voltmeter SEL#40. 5. White noise generator SEL#45. Note: Refer to subclause 5.5 suggested equipment list (SEL) for equipment details. 1.30.4 Equipment States Subject to Test Off-hook states with connection for through transmission. 1.30.5 Procedure Page 137 Telecommunications Industry Association TR41.9.1-10-05-002L In those cases where the interface impedances are not evident from the information provided, the tester is to contact the designer and request this information be provided so appropriate correction factors can be calculated for the through-transmission loss measurements. 1. Connect analog EUT to the test circuit of Figure 9.6-1 and establish connection between the ports under test for minimum current condition of each port as applicable. Otherwise, connect digital EUT, with through ports embedded in 1.544 Mb/s system, to the test circuits of Figure 9.6-2 and Figure 9.6-3. Establish a connection between the ports under test. 2. Set switch S1 to position "A." Adjust the filter to pass the band of frequencies below 3995 Hz. 1. If the EUT is band limited, then an appropriate filter adjustment is to be made. 3. Establish a through-transmission connection in the direction of the network interface under test. 4. Set the output level of the white noise generator so that the voltmeter indicates (-11) dBV. Maintain this level for all tests. 5. Set switch S1 to position "B" and measure the signal present at the output side of the EUT. 6. Calculate the gain of the through-transmission path from the input level set in step (4) and the output level measured in step (5). 7. Repeat step (1) through step (6) for the opposite direction of transmission of the EUT, if applicable. 8. Repeat step (2) through step (7) for each of the following conditions as applicable: 9. Minimum current through EUT input and maximum current through EUT output; 10. Maximum current through EUT input and maximum current through EUT output; 11. Maximum current through EUT input and minimum current through EUT output. 1.30.6 Alternative Methods A discrete or swept frequency method may also be used. Page 138 Telecommunications Industry Association TR41.9.1-10-05-002L 1.30.7 Suggested Test Data 1. Through-transmission paths. 2. Signal output levels from the EUT. 3. Calculated net amplification or loss, and associated frequency. 1.30.8 Comments 1. The net amplification may exceed the limit provided the absolute signal power levels specified in TIA-968-B subclause 4.4.1.1 for the interfaces in question are not exceeded. 2. If a swept frequency method is used, gain ripples in the passband may occur if an impedance mismatch exists between the EUT and the source, or between the EUT and the measuring device. Page 139 Telecommunications Industry Association Page 140 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1. Select the appropriate loop simulator, holding circuit, or termination for the interface of the EUT. Refer to the figures of clause 1 of TIA-968-B. 2. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. The output impedance of the signal source should be such that, in combination with or in place of R1 of the two-wire loop simulator circuit, the source impedance is either 600 ohms or matches the circuit of TIA968-B Figure 1.8. 4. The resistor R1 of the loop simulator may be replaced with the circuit of Figure 1.8 even though other subclauses of TIA-968-B specifies 600 ohms (e.g. Table 4.6, Note 1). Figure 9.6-1 Through Transmission, Analog 1. Select the appropriate loop simulator, holding circuit, or termination for the interface of the EUT. 2. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. The output impedance of the signal source should be such that, in combination with or in place of R1 of the two-wire loop simulator circuit, the source impedance is either 600 ohms or matches the circuit of TIA968-B Figure 1.8. 4. The resistor R1 of the loop simulator may be replaced with the circuit of Figure 1.8 even though other subclauses of TIA-968-B specifies 600 ohms (e.g. Table 4.6, Note 1). Figure 9.6-2. Through Transmission, Digital Page 141 Telecommunications Industry Association Page 142 TR41.9.1-10-05-002L Telecommunications Industry Association Figure 9.6-3. Digital EUT Arrangement for Figure 9.6-2 Page 143 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.31 Through-Transmission - SF Cutoff TIA-968-B, 4.7.5 1.31.1 Background The single frequency (SF) cutoff limitations in this subclause apply only when the EUT has a through path connecting either voiceband private lines, channels, or voiceband metallic channels to other network interfaces. This limitation ensures that no signals containing energy primarily in the SF band are transmitted across the network interfaces. The comparator in the network's SF signaling circuitry will not activate on SF signal bursts of 20 ms or less. 1.31.2 Purpose To verify that signals in the 2450 Hz to 2750 Hz band are not transmitted into the network facility unless there is at least an equal amount of energy in the 800 Hz to 2450 Hz band within 20 ms of application of signal. 1.31.3 Equipment 1. Applicable loop simulator SEL#4. 2. Bandpass filter SEL#6. 3. Digital sampling storage oscilloscope SEL#23. 4. Frequency generator SEL#27. 5. Multiplexer/demultiplexer SEL#32. 6. Summing network SEL#35. 7. True rms AC voltmeter SEL#40. 8. White noise generator SEL#45. Note: Refer to subclause 5.5 for equipment details. 1.31.4 Equipment States Subject to Test Off-hook states with connection for through transmission. Page 144 Telecommunications Industry Association TR41.9.1-10-05-002L 1.31.5 Procedure 1. Connect the EUT to the test circuit of Figure 9.7-1. Establish a connection between the ports under test. 2. Set switch S1 to position "A" and switch S2 to position "B." 3. Adjust the output level of the white noise generator to read -15 dBV on the voltmeter. 4. Set switch S1 to position "B" and switch S2 to position "A." 5. Adjust the output of the frequency generator to read -14 dBV on the voltmeter. 6. Set switch S1 to position "A," and measure on the oscilloscope time between the switch closure and the moment of signal cutoff. 1.31.6 Alternative Methods None suggested. 1.31.7 Suggested Test Data 1. Through-transmission paths. 2. Length of time interval when the EUT stops through transmission. 1.31.8 Comments None. 1. Select the appropriate loop simulator, holding circuit, or termination for the interface of the EUT. For digital interfaces, use a mux/demux and zero level decoder or companion terminal equipment. 2. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. The resistor R1 of the loop simulator may be replaced with the circuit of TIA-968-B Figures 1.8. Page 145 Telecommunications Industry Association Figure 9.7-1. Single Frequency Cut-off Page 146 TR41.9.1-10-05-002L Telecommunications Industry Association Page 147 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.32 Through-Transmission - SF/Guard Bands TIA-968-B, 4.7.4 1.32.1 Background EUT can provide a transmission path that connects together two or more network facilities. The purpose of the SF/guard band limitations in this subclause is to ensure that a signal passing through the EUT will not be incorrectly interpreted as the SF signal. 1.32.2 Purpose To compare the insertion loss for analog and digital equipment in the 800 Hz to 2450 Hz band to the insertion loss in the 2450 Hz to 2750 Hz band. 1.32.3 Equipment 1. Applicable loop simulator SEL#4. 2. Frequency generator SEL#27. 3. Multiplexer/demultiplexer SEL#32 (if required). 4. True rms voltmeter SEL#40. Note: Refer to subclause 5.5 for equipment details. 1.32.4 Equipment States Subject to Test Operating state where a through connection is established between the two EUT ports under test. 1.32.5 Procedure Page 148 Telecommunications Industry Association TR41.9.1-10-05-002L 1. Connect analog EUT to the test circuit of Figure 9.8-1 and establish connection between the ports under test for minimum current condition of each port as applicable. Otherwise, connect digital EUT, with through ports imbedded in 1.544 Mb/s systems, to the test circuits of Figure 9.8-2 and Figure 9.8-3 and establish connection between ports under test. 2. Set switch S1 to position "B." 3. Set the generator to 800 Hz and adjust the output level to (-11) dBV as measured by the voltmeter (see comment (4)). 4. Set switch S1 to position "A" and measure and record the input level of the EUT. 5. Calculate the gain at 800 Hz as the difference between the level set in step (3) and the level measured in step (4). 6. Repeat step (2) through step (5) for frequencies of 1000, 2000, 2300, and 2600 Hz. 7. Repeat step (2) through step (6) for each of the following conditions as applicable: 8. Minimum current through EUT input and maximum current through EUT output 9. Maximum current through EUT input and maximum current through EUT output 10. Maximum current through EUT input and minimum current through EUT output 11. If significant ripple is noticed, i.e., the change in gain over the frequency range is not smooth and monotonic, then with switch S1 in position "B," sweep the frequency range from 800 Hz to 2450 Hz noting the frequency at which the minimum value is indicated on the voltmeter. Sweep the frequency range from 2450 Hz to 2750 Hz noting the frequency at which the maximum value is indicated on the voltmeter. Repeat step (2) through step (7) for these two frequencies with the minimum and maximum amplitude values. 12. Repeat step (2) through step (8) for the opposite direction, if applicable. 1.32.6 Alternative Methods A method employing a white noise source and two bandpass filters may be used. Page 149 Telecommunications Industry Association TR41.9.1-10-05-002L 1.32.7 Suggested Test Data 1. Input level. 2. Frequency or frequency band. 3. Output level. 4. Through transmission paths. 5. Comparison data. 6. Loop simulator currents. 1.32.8 Comments 1. Measure each combination of port types. Check all other operating modes, such as conferencing, which might cause variations. 2. Where a device has several identical ports, only one representative sample of each through-transmission combination needs to be measured. 3. A loop simulator circuit may be used when needed on the input and output ports in place of the 600 ohm termination. 4. The EUT input test level that should be used in testing protective circuits for compliance is found in step (5) of subclause 9.1 for voice EUT, and in step (5) of subclause 9.5 for data EUT. 1. Select the appropriate loop simulator, holding circuit, or termination for the interface of the EUT. Page 150 Telecommunications Industry Association TR41.9.1-10-05-002L 2. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. The output impedance of the signal source should be such that, in combination with or in place of R1 of the two-wire loop simulator circuit, the source impedance is either 600 ohms or matches the circuit of TIA968-B Figures 1.8 4. The resistor R1 of the loop simulator may be replaced with the circuit of TIA-968-B Figures 1.8. Figure 9.8-1. Through Transmission - SF Guard Bands, Analog Page 151 Telecommunications Industry Association Page 152 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1. Select the appropriate loop simulator, holding circuit, or termination for the interface of the EUT. 2. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. The output impedance of the signal source should be such that, in combination with or in place of R1 of the two-wire loop simulator circuit, the source impedance is either 600 ohms or matches the circuit of TIA968-B Figures 1.8 4. The resistor R1 of the loop simulator may be replaced with the circuit of TIA-968-B Figures 1.8. Figure 9.8-2. Through Transmission - SF Guard Bands, Digital Page 153 Telecommunications Industry Association Page 154 TR41.9.1-10-05-002L Telecommunications Industry Association Figure 9.8-3. Digital EUT Arrangement for Figure 9.8-2 Page 155 TR41.9.1-10-05-002L Telecommunications Industry Association Page 156 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.33 Return Loss, Tie Trunk - Two Wire TIA-968-B, 5.1.5.4 (c1) 1.33.1 Background Poor impedance matching of the CPE connecting to a tie trunk facility could result in circuit instability, characterized by singing or echoing, and can cause crosstalk interference; therefore good impedance matching is essential. Return Loss is a measure of the degree of impedance match, i.e., the greater the magnitude (expressed in dB) the better the match. 1.33.2 Purpose To measure the return loss of the various Tie Trunk interface ports of the EUT as referenced to the appropriate impedance requirement. The impedance requirement for two-wire Tie trunks is 600 ohms in series with 2.16 microfarads (µF). 1.33.3 Equipment (1) Spectrum analyzer SEL#34. (2) Tracking generator SEL#39. Note: Refer to subclause 5.5 for equipment details. 1.33.4 Equipment States Subject To Test Idle state. 1.33.5 Procedure (1) Connect the EUT to the test circuit of Figure 9.9-1. (2) Set the tracking generator to 0.5 V rms (-6 dBV) or higher, and manually or automatically sweep the band from 200 Hz to 3200 Hz as a minimum, with the spectrum analyzer measuring the level, in dBV, across points A and B (switch S1 in position "A"). This is the reference level measurement. Page 157 Telecommunications Industry Association TR41.9.1-10-05-002L (3) Without adjusting the tracking generator level, manually or automatically sweep the same frequency band as used in step (2) with the spectrum analyzer now measuring the level, in dBV, across points B and C (switch in position "B"). (4) The difference, in dB, between the reference level measured in step (2) and the level measured in step (3), is the return loss of the EUT port at any given frequency. The return loss will be a positive value. 1.33.6 Alternative Methods A commercial return loss bridge may be used instead of the bridge of Figure 9.9-1. 1.33.7 Suggested Test Data (1) Return loss of the EUT at 200, 500, 1000, 2000, and 3200 Hz. (2) Minimum return loss measured in the 200 Hz to 3200 Hz band. 1.33.8 Comments A variable frequency oscillator and a broadband or frequency selective voltmeter may be used instead of the tracking generator and spectrum analyzer. Page 158 Telecommunications Industry Association Page 159 TR41.9.1-10-05-002L Telecommunications Industry Association Figure 9.9-1. Return Loss, Two-Wire Page 160 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.34 Return Loss, Tie Trunk - Four Wire TIA-968-B, 5.1.5.4 (C2) 1.34.1 Background Good return loss and transducer loss of the EUT connecting to a tie trunk facility (usually a fourwire low loss connection) will prevent circuit instability characterized by singing and echoes. Singing can result in crosstalk interference. Subclause 9.10 deals with four-wire return loss and subclause 9.11 deals with transducer loss. 1.34.2 Purpose To measure the return loss of the various Tie Trunk input and output interface ports of the EUT as referenced to the appropriate impedance requirement. The impedance requirement for fourwire ports of the EUT is 600 ohms. 1.34.3 Equipment (1) Spectrum analyzer SEL#34. (2) Tracking generator SEL#39 Note: Refer to subclause 5.5 for equipment details. 1.34.4 Equipment States Subject to Test Idle state. 1.34.5 Procedure (1) Connect the EUT to the test circuit of Figure 9.10-1. (2) Set the tracking generator to 0.5 V rms (-6 dBV) or higher, and manually or automatically sweep the band from 200 Hz to 3200 Hz as a minimum, with the spectrum analyzer measuring the level, in dBV, across points A and B (switch in position "A"). This is the reference level measurement. Page 161 Telecommunications Industry Association TR41.9.1-10-05-002L (3) Without adjusting the tracking generator level, manually or automatically sweep the same frequency band as used in step (2) with the spectrum analyzer now measuring the level, in dBV, across points B and C (switch in position "B"). (4) The difference, in dB, between the reference level measured in step (2) and the level measured in step (3), is the return loss of the EUT port at any given frequency. The return loss will be a positive value. (5) Connect the EUT to the test circuit as shown in Figure 9.10-2. (6) Repeat step (2) through step (4). 1.34.6 Alternative Methods A commercial return loss bridge may be used instead of the bridge of Figure 9.10-1. 1.34.7 Suggested Test Data (1) Return loss of the tip and ring leads of the EUT at 200, 500, 1000, 2000, and 3200 Hz. (2) Minimum return loss of the tip and ring leads of the EUT measured in the 200 Hz to 3200 Hz band. (3) Return loss of the tip 1 and ring 1 leads of the EUT at 200, 500, 1000, 2000, and 3200 Hz. (4) Minimum return loss of the tip 1 and ring 1 leads of the EUT measured in the 200 Hz to 3200 Hz band. 1.34.8 Comments When measuring return loss, a variable frequency oscillator and a broadband or frequency selective voltmeter may be used instead of the tracking generator and spectrum analyzer. Page 162 Telecommunications Industry Association Page 163 TR41.9.1-10-05-002L Telecommunications Industry Association Figure 9.10-1. Return Loss, Four-Wire, T&R Page 164 TR41.9.1-10-05-002L Telecommunications Industry Association Page 165 TR41.9.1-10-05-002L Telecommunications Industry Association Figure 9.10-2. Return Loss, Four-Wire, T1&R1 Page 166 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.35 Transducer Loss, Tie Trunk - Four Wire TIA-968-B, 5.1.5.4 (C4) 1.35.1 Background Refer to subclause 9.10.1. 1.35.2 Purpose To measure the transducer loss from the receive port to the transmit port of a four-wire Tie Trunk interface (forward direction) and from the transmit port to the receive port (reverse direction). 1.35.3 Equipment (1) Spectrum analyzer SEL#34 (2) Tracking generator SEL#39. Note: Refer to subclause 5.5 for equipment details. 1.35.4 Equipment States Subject to Test Idle state. Page 167 Telecommunications Industry Association TR41.9.1-10-05-002L 1.35.5 Procedure (1) Adjust the tracking generator output level to -10.0 dBV into a 600-ohm load, measured at 1004 Hz. Sweep the band from 200 Hz to 3200 Hz with the spectrum analyzer measuring the level in dBV. This is the reference level measurement. (2) Connect the EUT to the test circuit of Figure 9.11-1. (3) Without adjusting the tracking generator level, sweep the same frequency band as used in step (1) with the spectrum analyzer measuring the level in dBV. (4) The difference, in dB, between the reference level measured in step (1) and the level measured in step (3), is the forward transducer loss of the EUT port at any given frequency. (5) Connect the EUT to the test circuit of Figure 9.11-2. (6) Repeat step (3) and step (4) to measure the reverse transducer loss. 1.35.6 Alternative Methods None suggested. 1.35.7 Suggested Test Data Forward and reverse transducer losses at 200, 500, 1000, 2000, and 3200 Hz. 1.35.8 Comments Transducer loss is expressed as a ratio of current in the receive pair as compared to the transmit pair. This specific test procedure uses a more practical method by determining the ratio of voltages instead of currents. This method is acceptable as long as the correct impedances are maintained. Note: The source impedance of the tracking generator is 600 ohms. Figure 9.11-1. Transducer Loss, Forward Page 168 Telecommunications Industry Association Note: The source impedance of the tracking generator is 600 ohms. Figure 9.11-2 Transducer Loss, Reverse Page 169 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.36 DC Conditions, OPS TIA-968-B, 5.1.16 1.36.1 Background Off-premise station (OPS) ports of premises communication systems (e.g., private branch exchanges or key telephone systems) provide DC loop supervision network control signaling and talking battery to the remote OPS stations (refer also to subclause 8.3). 1.36.2 Purpose To verify that the voltage and current capabilities of the OPS port of the EUT are compatible with the network requirements and that it provides sufficient direct current for proper operation of network facilities and the remote OPS equipment. 1.36.3 Equipment (1) Applicable loop simulator SEL#4 (2) DC current meter SEL#19. (3) DC voltmeter SEL#22. Note: Refer to subclause 5.5 for equipment details. 1.36.4 Equipment States Subject To Test Active state. 1.36.5 Procedure Note: The requirements of TIA-968-B, 4.5.2.7.1 and 4.5.2.7.2.1 are addressed in TIA-968-B, 4.4.1.4.1 and the test procedures are covered in subclause 8.3 1. Connect the EUT to test circuit of Figure 9.12-1. 2. Place the EUT into the talking state. Page 170 Telecommunications Industry Association TR41.9.1-10-05-002L 3. For Class B and Class C OPS interfaces, close switch S1, and measure the short circuit current between T(OPS) and R(OPS). 4. Open switch S1. 5. Place the OPS simulator into condition "1." 6. Adjust R2 as given in the table of TIA-968-B, 4.5.2.7.2.3 for Class B and Class C OPS interfaces. 7. Record the current flowing in the circuit. 8. Place the simulator circuit into condition "2" and repeat step (5) through step (7). 1.36.6 Alternative Methods None suggested. 1.36.7 Suggested Test Data 1. Short circuit current (mA) for Class B and C OPS interfaces. 2. Minimum current under conditions "1" and "2" for Class B and C OPS interfaces. 1.36.8 Comments 1. The minimum and maximum current requirements do not apply to Class A OPS interfaces. See subclause 8.3 for Class A OPS limitations. 2. The DC current into the OPS loop simulator circuit should be at least 20 mA for conditions 1 and 2 specified in the table of TIA-968-B, 4.5.2.7.2.3. Note: Loop current is measured with a current meter in series with the OPS loop simulator. Refer to the TIA968-B Figure 1.7. Figure 9.12-1. OPS DC Conditions Page 171 Telecommunications Industry Association TR41.9.1-10-05-002L 1.37 Signal Power 3995 Hz - 4005 Hz – Not Network Control Signals TIA-968-B, 5.1.6.1 1.37.1 Background It is necessary that the signal power in the 3995 Hz to 4005 Hz band be limited so that the transmitted signal does not interfere with the modulating carrier frequencies of multichannel carrier systems. Limits are be specified on both internal signal sources and through gain of terminal equipment in the 3995 Hz to 4005 Hz frequency band. An absolute level restriction is necessary for internal sources; an insertion loss restriction is necessary for through gain equipment. The insertion loss restriction is such that the equipment will not increase the signal level near 4 kHz relative to the level of the normal voiceband frequencies. 1.37.2 Purpose To verify for the EUT that the voiceband signal power from internal sources, other than livevoice, is limited in the 3995 Hz to 4005 Hz frequency band. 1.37.3 Equipment (1) Applicable loop simulator SEL#4. (2) Bandpass filter SEL#8 (3) True rms AC voltmeter SEL#40. Note: Refer to subclause 5.5 for equipment details. 1.37.4 Equipment States Subject To Test (1) Off-hook, idle state. (2) Any off-hook state which transmits signals to the PSTN which are not intended for network control. Page 172 Telecommunications Industry Association TR41.9.1-10-05-002L 1.37.5 Procedure (1) Connect the EUT to the circuit of Figure 9.13-1. (2) Set the voltmeter to measure the signal level in dBm. (3) Place the EUT in the off-hook state and cause it to transmit an internal signal at maximum power. (4) Measure and record the maximum signal power level in dBm at minimum and maximum loop currents attainable with the loop simulator, if applicable. (5) Repeat step (3) through step (4) for all other operating states. 1.37.6 Alternative Methods (1) Connect the EUT to the test circuit of Figure 9.13-1 and replace the bandpass filter and true rms AC voltmeter with a signal analyzer (SEL#56). (2) Set the signal analyzer to measure the following: (a) Signal level in dBm, 600 ohms. (b) Averaging over 3 second. (c) Band pass power in the frequency range of 3995 Hz to 4005 Hz band. Note: Signal Analyzer should provide a balanced input, or an isolation transformer may be used. (3) Place the EUT in the desired off-hook state and cause it to transmit an internal signal at maximum power. (4) Measure and record the maximum signal power level in dBm at minimum and maximum loop currents attainable with the loop simulator, if applicable. (5) Repeat step (2) through step (4) for other operating states, if applicable. Page 173 Telecommunications Industry Association Page 174 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.37.7 Suggested Test Data (1) Operating states. (2) Signal power levels in dBm for the 3995 Hz to 4005 Hz band. 1.37.8 Comments (1) All references to dBm are with respect to 600 ohms. (2) For EUT using recorded voice or synthesized voice, a message using both male and female voices speaking a typical sentence that is repeated for a total length of about 30 seconds, or long enough to obtain a 3 second average power in the 3995 Hz to 4005 Hz band is suggested. (3) A voltmeter with an averaging time of less than 3 seconds may be used, provided that the measured value is adjusted based on the duty cycle of the signals. (4) The roll-off used in bandpass filters of the CODECs in digital EUTs causes the signal power in the 3995 Hz to 4005 Hz band to be at least 30 dB down from the reference value at 1000 Hz. Hence this requirement does not apply to digital EUT. 1. Select the appropriate loop simulator for the interface of the EUT. 2. Connect the bandpass filter across R1 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. Figure 9.13-1. Signal Power, 3995-4005 Hz, Internal Sources Page 175 Telecommunications Industry Association Page 176 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.38 Through Transmission – 3995-4005 Hz vs 600-4000 Hz TIA-968-B, 5.1.6.2 1.38.1 Background The basis for this requirement is identical to that described in subclause 9.13 1.38.2 Purpose To verify for the EUT that through transmission of signals, is limited in the 3995 Hz to 4005 Hz frequency band vs the 600 Hz to 4000 Hz frequency band. 1.38.3 Equipment (1) Applicable loop simulator SEL#4. (2) Bandpass filter SEL#8 (3) Bandpass filter SEL#14. (4) Frequency generator SEL#27 (5) True rms AC voltmeter SEL#40. (6) White noise generator SEL#45. Note: Refer to subclause 5.5 for equipment details. 1.38.4 Equipment States Subject To Test (1) All equipment with through-transmission paths to the PSTN are subject to test. Page 177 Telecommunications Industry Association Page 178 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.38.5 Procedure 1. Connect the EUT to the test circuit of Figure 9.14-1 and establish connection between the ports under test for minimum current condition of each port as applicable. 2. Set switch S1 to position "A" and switch S2 to position "A." 3. Set the filter to pass the band of frequencies from 600 Hz to 3995 Hz. 4. Adjust the level of the white noise generator so that the voltmeter indicates 11 dBV. 5. Set switch S1 to position "B" and measure the signal present at the output side of the EUT. 6. Calculate the gain of the through-transmission path in the band from 600 Hz to 3995 Hz from the levels obtained in step (4) and step (5). 7. Set switch S1 to position "A" and switch S2 to position "B." 8. Set the frequency generator to 4000 Hz and adjust the level to match the level in step (4). 9. Set switch S1 to position "B" and measure the signal level. 10. Calculate the gain at 4000 Hz from the level obtained in step (8) and (9). 11. Repeat step (2) through step (10) for each of the following conditions as applicable: 1. Minimum current through EUT input and maximum current through EUT output. 2. Maximum current through EUT input and maximum current through EUT output. 3. Maximum current through EUT input and minimum current through EUT output. 1.38.6 Alternative Methods A discrete or swept frequency method may also be used. Page 179 Telecommunications Industry Association Page 180 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.38.7 Suggested Test Data (1) Types of through-transmission paths. (2) Calculated net gain in the 600 Hz to 3995 Hz band. (3) Calculated net gain at 4000 Hz. (4) Loop simulator currents. 1.38.8 Comments (1) All references to dBm are with respect to 600 ohms. (2) A voltmeter with an averaging time of less than 3 seconds may be used, provided that the measured value is adjusted based on the duty cycle of the signals. (3) The roll-off used in bandpass filters of the CODECs in digital EUTs causes the signal power in the 3995 Hz to 4005 Hz band to be at least 30 dB down from the reference value at 1000 Hz. Hence this requirement does not apply to digital EUT. 1. Select the appropriate loop simulator, holding circuit, or termination for the interface of the EUT. 1. Connect the bandpass filter across R1 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 1. The source impedance of the signal generator should be such that, in combination with or in place of R1 of the loop simulator circuit, the source impedance is either 600 ohms or matches the impedance of the circuit of Figure 1.8 in TIA-968-B. 1. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. Figure 9.14-1 Signal Power, 3995-4005 Hz vs 600-4000 Hz, Through Transmission Page 181 Telecommunications Industry Association Page 182 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.39 Non-LADC Longitudinal Voltage – 0.1 - 4 kHz TIA-968-B, 5.1.7 1.39.1 Background This requirement ensures that spurious or unintended signals transmitted from terminal equipment at frequencies in the voiceband do not interfere with telephone company transmission systems operating in that frequency range as a result of crosstalk. 1.39.2 Purpose To verify that the EUT does not apply excessive longitudinal power to the PSTN in the voiceband. 1.39.3 Equipment (1) Applicable loop simulator SEL#4 (2) Bandpass filter SEL#12. (3) True rms AC voltmeter SEL#40. (4) Spectrum analyzer SEL#34 (5) Frequency Generator SEL#27 Note: Refer to subclause 4.3 for equipment details. 1.39.4 Equipment States Subject to Test (1) On-hook. (2) All active operating states. Page 183 Telecommunications Industry Association TR41.9.1-10-05-002L Note: Terminal equipment may require special attention to ensure it is properly configured for this test. For example, if the equipment would normally be connected to ac-power ground, cold-water-pipe ground, or if it has a metallic or partially metallic exposed surface, then these points should be connected to the test ground plane. Similarly, if the EUT provides connections to other equipment through which ground may be introduced to the equipment, then these points should be connected to the test ground plane. Equipment which does not contain any of these potential connections to ground should be placed on a conductive plate which is connected to the test ground plane (see comment 1); this applies to both non powered and ac-powered equipment. 1.39.5 Procedure (1) Connect the EUT to the test circuit of Figure 9.15-1. (2) Place the EUT in the on-hook state. (3) Set the bandpass filter to measure in the 100 Hz to 4000 Hz band and record the voltmeter reading. The weighting network has a transfer function of F/4000, where F is the frequency in Hz. Note: Correct the measured result for the voltage divider relationship of the termination. Adjustment is +3.1 dB. (4) Place the EUT in one of the off-hook states. Conduct these tests in accordance with the conditions of TIA-968-B subclause 4.5.7.1 to 4.5.7.3, as appropriate (see comment 3 and 4). (5) Repeat step (3) for all possible off-hook states. Note: step (3) through step (5) should be measured at minimum and maximum loop currents attainable with the loop simulator for all off-hook states, if applicable. 1.39.6 Alternative Methods (1) Connect the EUT to the test circuit of Figure 9.15-1 and replace the bandpass filter and true rms AC voltmeter with a spectrum analyzer. (2) Place the EUT in the on-hook state. Page 184 Telecommunications Industry Association TR41.9.1-10-05-002L (3) Set the spectrum analyzer to measure in the 100 Hz to 4000 Hz band and record the result. See comment (2). Note: Correct the measured result for the voltage divider relationship of the termination. Adjustment is +3.1 dB. (4) Place the EUT in one of the off-hook states. Conduct these tests in accordance with the conditions of TIA-968-B subclause 4.5.7.1 to 4.5.7.3, as appropriate (see comment 3 and 4). (5) Repeat step (3) for all possible off-hook states. Note: step (3) through step (5) should be measured at minimum and maximum loop currents attainable with the loop simulator for all off-hook states, if applicable. 1.39.7 Suggested Test Data (1) Band measured. (2) Voltage level in dBV. (3) Equipment states. 1.39.8 Comments 1. An EUT that is not normally grounded should be set in its normal position directly on a conductive plate. The overall area of the conductive plate should be at least 50% greater than that of the base of the EUT. This represents the closest proximity to ground that is likely to be encountered by the EUT. 2. When using a spectrum analyzer the total rms voltage over the 100 Hz to 4 kHz band can be calculated using the expression: Vt = (V12 + V22 + . . . + Vn2 )0.5 where Vt is the total rms voltage over the 100 Hz to 4 kHz band and V1, V2, V3....Vn are the spectral components within that band that are within 20 dB of the limit for that band. Page 185 Telecommunications Industry Association TR41.9.1-10-05-002L 3. For approved terminal equipment or protective circuits with provision for throughtransmission from other equipment, apply a 1000 Hz signal from a 600 ohm source that results in a power output of (-13) dBm delivered into a 600 ohm load at the network interface. 4. For approved data protective circuits or approved terminal equipment or protective circuits with non-approved signal source input, such as music on hold, apply a 1000 Hz signal that is 10 dB higher then the overload level point. 5. See TIA-968-B subclause 4.5.7.1 through 4.5.7.3 for the conditions that apply for different equipment types. 1. Select the appropriate loop simulator for the interface of the EUT. 2. Connect the resistive network in place of R1 of the loop simulator. Refer to the figure 4.5 of TIA-968-B. Use 300 ohm resistors that are adequately matched. 3. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. Figure 9.15-1. Voiceband Longitudinal Voltage Page 186 Telecommunications Industry Association Page 187 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.40 Non-LADC Metallic Voltage - 4 kHz to 30 MHz TIA-968-B, 5.1.8.1, 5.1.8.2 1.40.1 Background This requirement ensures that spurious or unintended signals transmitted from terminal equipment at frequencies above voiceband do not interfere with telephone company transmission systems or services that function at such frequencies. The most limiting situations are those that involve subscriber multichannel analog carrier systems. These are systems that are used in the local exchange plant to obtain a wire pair gain advantage. In these systems, the signals to and from several subscribers are multiplexed onto a wire pair using frequency division. Each direction of transmission for each subscriber uses either 4 kHz (single sideband) or 8 kHz (double sideband) of frequency spectrum. Generally, the carrier systems most susceptible to crosstalk are those that use double sideband modulation methods, 8 kHz of spectrum for each direction of transmission per channel. Accordingly, the requirements in TIA-968-B are specified in 8 kHz bands relative to the center frequency of each band. Thus the limits in each band are based on the susceptibility of the affected analog multichannel carrier system, crosstalk characteristics of the wire pair cable facilities, and the characteristic terminating impedance of the cable facilities. The limit is therefore established for each 8 kHz band centered in the frequency specified in the tables up to 270 kHz. The 100-millisecond averaging time for frequencies less than 270 kHz approximates the minimum time necessary for the interfering signal to affect the transmission performance of subscriber analog carrier systems on other cable pairs. For frequencies greater than 270 kHz, a 2microsecond averaging time is specified. This averaging time is approximately the reciprocal of the Nyquist rate of "T" carrier. It represents the time interval appropriate to interference with the "T" carrier transmission. Such a signal duration will result in pulse interference and consequently transmission errors. One broadband requirement above 270 kHz is adequate. 1.40.2 Purpose To verify that the EUT does not apply excessive out-of-band power to the PSTN. 1.40.3 Equipment (1) Applicable loop simulator SEL#4. (2) Bandpass filter SEL#9 Page 188 Telecommunications Industry Association TR41.9.1-10-05-002L (3) Digital sampling storage oscilloscope SEL#24. (4) Spectrum analyzer SEL#34 (5) Frequency Generator SEL#27 Note: Refer to subclause 4.3 for equipment details. 1.40.4 Equipment States Subject to Test (1) On-hook. (2) All active operating states. 1.40.5 Procedure Note: See comments (1), (2), (3) and (6) before performing tests. (1) Connect the EUT to the test circuit of Figure 9.16-1. (2) Place the EUT in the on-hook state. (3) Select R1 to be 300 ohms. (4) Measure the energy in each 8 kHz band whose center frequency is in the range of 8 kHz to 12 kHz, and record the results. (5) Select R1 to be 135 ohms. (6) Measure the energy in each 8 kHz band whose center frequency is in the range of 12 kHz to 90 kHz, and record the results. (7) Measure the energy in each 8 kHz band whose center frequency is in the range of 90 kHz to 266 kHz and record the worst case result. (8) Place the EUT in each of its off-hook states as specified in TIA-968-B subclause 4.5.7.2, and condition the EUT as specified in TIA-968-B subclause 4.5.7.3 or 4.5.7.4, as appropriate (see comment 7 and 8). Page 189 Telecommunications Industry Association TR41.9.1-10-05-002L (9) Repeat step (3) through step (7) at minimum and maximum loop currents attainable with the loop simulator, if applicable. (10) Connect the EUT to the test circuit of Figure 9.16 2, and set the passband of the filter to measure broadband energy in the frequency range 270 kHz to 30 MHz (see comment 4 and 5). (11) Condition the EUT to the on-hook state. (12) Set the digital oscilloscope to provide: (a) 2 µs per sample; (b) Trigger at (-25) dBV; (c) Accumulate mode; (d) Vertical scale 0 mV to 250 mV full height. Note: If the baseline contains 1000 points then a single trace will take 2 ms. (13) Program the oscilloscope to accumulate 10 traces. (14) Record the value of the largest peak measured and convert to Vrms by multiplying by 0.707. (15) With the EUT in each of its active operating states as specified in TIA-968-B subclause 4.5.7.2, condition the EUT as specified in TIA-968-B subclause 4.5.7.3 or 4.5.7.4, as appropriate (see comment 7 and 8). (16) Repeat step (13) and step (14) at minimum and maximum loop currents attainable with the loop simulator, if applicable. 1.40.6 Alternative Method - Broadband Procedure Note: See comments (2), (3), and (5). (1) Connect the EUT to the test circuit of Figure 9.16-1. Page 190 Telecommunications Industry Association TR41.9.1-10-05-002L (2) Place the EUT in the on-hook state. (3) Select R1 to be 300 ohms. (4) Set the spectrum analyzer to measure broadband energy in the frequency range 4 kHz to 16 kHz, using the required termination, and record the result. (5) Select R1 to be 135 ohms. (6) Set the spectrum analyzer to measure broadband energy in the frequency range 8 kHz to 94 kHz, and record the result. (7) Set the spectrum analyzer to measure broadband energy in the frequency range 86 kHz to 270 kHz, and record the worst case result. (8) Set the spectrum analyzer to measure broadband energy in the frequency range 270 kHz to 6 MHz, and record the worst case result. (9) Set the spectrum analyzer to measure broadband energy in the frequency range 6 MHz to 30 MHz, and record the worst case result. (10) Place the EUT in each of its off-hook states as specified in TIA-968-B subclause 4.5.7.2, and condition the EUT as specified in TIA-968-B subclause 4.5.7.3 or 4.5.7.4, as appropriate (see comment 7 and 8). (11) Repeat step (3) through step (9) at minimum and maximum loop currents attainable with the loop simulator, if applicable. (12) If the test results obtained in step (4) and step (6) through step (9) do not exceed the maximum limits specified in TIA-968-B subclause 4.5.5.1, then no further tests are required (see comment 2). 1.40.7 Suggested Test Data (1) Center frequencies. (2) Start and stop frequencies. (3) Measured or calculated signal power values. (4) Equipment state. Page 191 Telecommunications Industry Association TR41.9.1-10-05-002L 1.40.8 Comments When using a detector that measures individual frequency components, the following procedure should be employed. (1) Total the voltages which are within 6 dB of the specified limit in each consecutive band. If the sum of these voltages exceeds the limits, recheck the measurement at a frequency centered over the band with the apparent failure. The total rms voltage can be calculated using the expression: Vt = (V12 + V22 + . . . + Vn2 )0.5 Note: This expression assumes that the spectral components have random phase relationships. Page 192 Telecommunications Industry Association TR41.9.1-10-05-002L (2) The broadband measurement procedure may be used for the purpose of economy of measurement. If the value obtained is lower than the most restrictive limit specified for that frequency range, then the signal levels in 8 kHz bands in that range will be lower than that specified for the most restrictive 8 kHz band. However, the main procedure of subclause 9.16.5 should be used when the requirements are not met as the signal levels in each band may still be within specified limits. Refer to TIA-968-B subclause 4.5.5.1. (3) If a spectrum analyzer is used and it does not have an 8 kHz bandwidth, a 10 kHz bandwidth may be used. Application of a correction factor, additional measurements, or both, may be required to compensate for the wider bandwidth. (4) If a failure condition is noted when a 10 kHz bandwidth is used and the spectral content has uneven distribution, it may be necessary to check that reading, using a higher resolution. (5) The total rms voltage over an 8 kHz band can be calculated using the expression: Vt = (V12 + V22 + . . . + Vn2 )0.5 where Vt is the total rms voltage over any 8 kHz band and V1, V2, V3....Vn are the spectral components within that band that are within 20 dB of the limit for the band in question. Note: This expression assumes that the spectral components have random phase relationships. If the spectral content of a band is evenly distributed, then the equivalent rms power in an 8 kHz band can be found by subtracting 1 dB from the measured power using a 10 kHz bandwidth. Since this is a measurement of a metallic (balanced) circuit, the only ground connection should be that of the line cord of the oscilloscope or spectrum analyzer. (6) See TIA-968-B subclause 4.5.7.2 through 4.5.7.4 for the conditions that apply for different equipment types. (7) For approved terminal equipment or protective circuits with provision for throughtransmission from other equipment, apply a 1000 Hz signal from a 600 ohm source that results in a power output of (-13) dBm delivered into a 600 ohm load at the network interface. Page 193 Telecommunications Industry Association TR41.9.1-10-05-002L (8) The EUT input test levels and frequencies that should be used in testing protective circuits for compliance with all out-of-band frequencies are as follows: (a) For approved data protective circuits, apply a 1000 Hz signal that is 10 dB higher then the overload point as determined in subclause 9.34.5. (b) For approved terminal equipment or approved protective circuits with non-approved signal source input, such as music on hold, apply a swept sinusoidal signal with a frequency range of 200 Hz to 20 kHz and the level set at the overload point determined in subclause 9.34.5. Page 194 Telecommunications Industry Association Page 195 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1. Select the appropriate loop simulator for the interface of the EUT. 2. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. The resistor shown (R1) is connected in place of R1 as shown in the loop simulator drawing. The resistor has a value of 300 ohms for frequencies of 4 kHz to 12 kHz and 135 ohms for frequencies of 12 kHz to 30 MHz. Capacitor C1 of the loop simulator should be capable of coupling the frequencies covered by this test. 4. The spectrum analyzer should provide a balanced input, or an isolation transformer or balun transformer may be used. Figure 9.16-1. Non-LADC Metallic 4 kHz to 30 MHz 1. Select the appropriate loop simulator for the interface of the EUT. 2. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. The resistor shown (R1) is connected in place of R1 as shown in the loop simulator drawing. The resistor has a value of 135 ohms. Capacitor C1 of the loop simulator should be capable of coupling the frequencies covered by this test. 4. The oscilloscope should provide a balanced input, or an isolation transformer or balun transformer may be used. Figure 9.16-2. Non-LADC Metallic 270 kHz to 30 MHz Page 196 Telecommunications Industry Association TR41.9.1-10-05-002L 1.41 Non-LADC Longitudinal Voltage - 4 kHz to 6 MHz TIA-968-B, 5.1.8.3, 5.1.8.4 1.41.1 Background The basis for these requirements is identical to that described in subclause 8.16.1 except that the wire pair crosstalk characteristics are such that there is greater crosstalk coupling with longitudinal voltages. Thus, there are limits on both in-band and out-of-band longitudinal voltages. 1.41.2 Purpose To verify that the EUT does not apply any excessive out-of-band longitudinal signal power to the PSTN. 1.41.3 Equipment (1) Applicable loop simulator SEL#4 (2) Bandpass filter SEL#9 (3) Digital sampling storage oscilloscope SEL#24. (4) Spectrum Analyzer SEL#34 (5) Frequency Generator SEL#27 Note: Refer to subclause 4.3 for equipment details. 1.41.4 Equipment States Subject to Test (1) On-hook. (2) All active operating states. Note: Terminal equipment may require special attention to ensure it is properly configured for this test. For example, if the equipment would normally be connected to ac-power ground, cold-water-pipe ground, or Page 197 Telecommunications Industry Association TR41.9.1-10-05-002L if it has a metallic or partially metallic exposed surface, then these points should be connected to the test ground plane. Similarly, if the EUT provides connections to other equipment through which ground may be introduced to the equipment, then these points should be connected to the test ground plane. Equipment which does not contain any of these potential connections to ground should be placed on a conductive plate which is connected to the test ground plane (see comment 6); this applies to both non powered and ac powered equipment. Page 198 Telecommunications Industry Association Page 199 TR41.9.1-10-05-002L Telecommunications Industry Association Page 200 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.41.5 Procedure Note: See comments (1), (2), (3) and (5). (1) Connect the EUT to the test circuit of Figure 9.17-1. (2) Place the EUT in the on-hook state. (3) Select R1 = R2 = 150 ohms and R3 = 425 ohms. (4) Measure the energy in each 8 kHz band whose center frequency in the range of 8 kHz to 12 kHz and record the result. Note: The measured result should be corrected for the voltage divider relationship of the termination. Adjustment is (+1.4) dB. (5) Select R1 = R2 = 67.5 ohms and R3 = 56.3 ohms. (6) Measure the energy in each 8 kHz band whose center frequency is in the range 12 kHz to 42 kHz and record the result. (7) Measure the energy in each 8 kHz band whose center frequency is in the range 42 kHz to 266 kHz and record the worst case result. Note: Correct the results measured in step (6) and step (7) for the voltage divider relationship of the termination. Adjustment is (+4) dB. (8) Place the EUT in each of its off-hook states as specified in TIA-968-B subclause 4.5.7.2, and condition the EUT as specified in TIA-968-B subclause 4.5.7.1, 4.5.7.3 or 4.5.7.4, as appropriate (see comment 9 and 10). (9) Repeat step (6) and step (7) at minimum and maximum loop currents attainable with the loop simulator, if applicable. (10) Connect the EUT to the test circuit of Figure 9.17-2 and set the passband of the filter to measure broadband energy in the range 270 kHz to 6 MHz. (see comment 6 and 7). Page 201 Telecommunications Industry Association (11) Place the EUT in the on-hook state. Page 202 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L (12) Set the digital oscilloscope to provide: (a) 2 microseconds (µs) per sample; (b) Trigger at -40 dBV; (c) Accumulate mode; (d) Vertical scale 0 mV to 250 mV full height. Note: If the baseline contains 1000 points then a single trace will take 2 ms. (13) Program the oscilloscope to accumulate 10 traces. (14) Record the value of the largest peak measured and convert to V rms by multiplying by 0.707. Note: Correct the results measured in step (14) for the voltage divider relationship of the termination. Adjustment is (+4) dB. (15) With the EUT in each of its active operating states as specified in TIA-968-B subclause 4.5.7.2, condition the EUT as specified in TIA-968-B subclause 4.5.7.1, 4.5.7.3 or 4.5.7.4, as appropriate (see comment 9 and 10). (16) Repeat step (13) and step (14) at minimum and maximum loop currents attainable with the loop simulator, if applicable. 1.41.6 Alternative Methods - Broadband Procedure (1) Connect the EUT to the test circuit of Figure 9.17-1. (2) Place the EUT in the on-hook state. (3) Select the R1 = R2 = 150 ohms and R3 = 425 ohms. (4) Set the spectrum analyzer to measure broadband energy in the 4 kHz to 16 kHz band and record the result. Page 203 Telecommunications Industry Association TR41.9.1-10-05-002L Note: Correct the results in step (4) by (+1.4) dB to accommodate the voltage divider. (5) Select R1 = R2 = 67.5 ohms and R3 = 56.3 ohms. (6) Set the spectrum analyzer to measure broadband energy in the 12 kHz to 46 kHz band and record the result. (7) Set the spectrum analyzer to measure broadband energy in the 42 kHz to 270 kHz band and record the worst-case result. (8) Set the spectrum analyzer to measure broadband energy in the 270 kHz to 6 MHz band and record the worst-case result. Note: Correct the results in step (6) and step (8) by (+4) dB to accommodate the voltage divider. (9) Place the EUT in each of its off-hook states as specified in TIA-968-B subclause 4.5.7.2, and condition the EUT as specified in TIA-968-B subclause 4.5.7.1, 4.5.7.3 or 4.5.7.4, as appropriate (see comment 9 and 10). (10) Repeat step (3) through step (8) at minimum and maximum loop currents attainable with the loop simulator, if applicable. 1.41.7 Suggested Test Data (1) Center frequencies. (2) Start and stop frequencies. (3) Power levels, measured or calculated. (4) Equipment state. 1.41.8 Comments (1) When measuring with a detector that measures individual frequency components, the following procedure should be used. (2) For all measured voltages within 6 dB of the specified limit in each consecutive band, calculate the total rms voltage as shown below. If the sum of these voltages exceeds the Page 204 Telecommunications Industry Association TR41.9.1-10-05-002L limit of the most restrictive value for these bands, then recheck the measurement at sufficient frequencies centered over the bands involved in the failure. The total rms voltage can be calculated using the expression: Vt = (V12 + V22 + . . . + Vn2 )0.5 Note: This expression assumes that the spectral components have random phase relationships. (4) The broadband measurement procedure may be employed for the purpose of economy of measurement. If the value obtained is lower than the most restrictive limit specified for that frequency range, then the signal levels in any 8 kHz band in that range will be lower than the limit specified for the most restrictive 8 kHz band. However, the main procedure of subclause 9.17.5 should be used when the requirements are not met as the signal levels in each bandwidth may still be within specified limits. Refer to TIA-968-B subclause 4.5.5.2. (5) If a spectrum analyzer is used and it does not have an 8 kHz bandwidth, a 10 kHz bandwidth may be used. Application of a correction factor, additional measurements, or both, may be required to compensate for the wider bandwidth. (6) If a failure condition is noted when a 10 kHz bandwidth is used and the spectral content has uneven distribution, it may be necessary to check that reading, using a higher resolution. (7) The total rms voltage over an 8 kHz band can be calculated by the following impression: Vt = (V12 + V22 + . . . + Vn2 )0.5 where Vt is the total rms voltage over an 8 kHz band and V1, V2, V3...Vn are the spectral components within that band and are within 20 dB of the limit for the band in question. Note: This expression assumes that the spectral components have random phase relationships. If the spectral content of a band is evenly distributed, the equivalent rms power in an 8 kHz band can be found by subtracting 1 dB from the measured power using a 10 kHz bandwidth. Page 205 Telecommunications Industry Association TR41.9.1-10-05-002L (8) See TIA-968-B subclause 4.5.7.1 through 4.5.7.4 for conditions that apply for different equipment types. (9) For approved terminal equipment or protective circuits with provision for throughtransmission from other equipment, apply a 1000 Hz signal from a 600 ohm source that results in a power output of -13 dBm delivered into a 600 ohm load at the network interface. (10) The EUT input test levels and frequencies that should be used in testing protective circuits for compliance with all out-of-band frequencies are as follows: (a) For approved data protective circuits, apply a 1000 Hz signal that is 10 dB higher then the overload point as determined in subclause 9.34.5. (b) For approved terminal equipment or protective circuits with non-approved signal source input, such as music on hold, apply a swept sinusoidal signal with a frequency range of 200 Hz to 20 kHz and the level set at the overload point determined in subclause 9.34.5. (11) EUT that is not normally grounded should be set in its normal position directly on a conductive plate. It is recommended that the overall area of the conductive plate be at least 50% greater than that of the base of the EUT. This represents the closest proximity to ground that is likely to be encountered by the EUT. 1. Select the appropriate loop simulator for the interface of the EUT. 2. Connect the resistive network in place of R1 of the loop simulator. Capacitor C1 of the loop simulator should be capable of coupling the frequencies covered by this test. The resistors R1 and R2 should be adequately matched. 3. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. Figure 9.17-1. Non-LADC Longitudinal 4 kHz to 6 MHz 1. Select the appropriate loop simulator for the interface of the EUT. 2. Connect the resistive network in place of R1 of the loop simulator. Capacitor C1 of the loop simulator should be capable of coupling the frequencies covered by this test. The resistors R1 and R2 should be adequately matched. Page 206 Telecommunications Industry Association TR41.9.1-10-05-002L 3. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. Figure 9.17-2. Non-LADC Longitudinal 270 kHz to 6 MHz Page 207 Telecommunications Industry Association TR41.9.1-10-05-002L 1.42 Metallic Voltage 0.01 kHz to 30 MHz, LADC TIA-968-B, 5.2.1.4.1, 5.2.1.4.2 1.42.1 Background The basic principle for establishing LADC signal power limits is similar to that for non LADC except that there is increased administration of the loop plant by the telephone companies in selecting wire pairs for digital transmission and analog carrier systems. Such administration results in the wire pairs selected not being in the same binder group. Increased administration stems from the fact that there is need to accommodate more digital transmission in the loop plant, which requires higher frequencies and greater signal power. The technical rules adopted here are based on the sensitivity of digital equipment to other digital signals for frequencies below 270 kHz and on basic voiceband equipment sensitivities to digital signals. The limits on the 8 kHz bands from 4 kHz to 270 kHz are based on analog multichannel carrier sensitivity but at significantly less stringent levels than required in non LADC applications because of the special administrative procedures followed for the digital system and analog carrier applications. 2. Purpose To verify that the EUT does not apply excessive metallic power to the network for LADC equipment. 2. Equipment 1. Applicable loop simulator SEL#4. 2. Bandpass filter SEL#9. 3. Bandpass filter SEL#10. 4. Bandpass filter SEL#11. 5. Companion terminal equipment SEL#15. 6. Digital sampling storage oscilloscope SEL#24. 7. Spectrum Analyzer SEL#34. Page 208 Telecommunications Industry Association TR41.9.1-10-05-002L 8. True rms AC voltmeter SEL#40. Note: Refer to subclause 5.5 for equipment details. 2. Equipment States Subject to Test Active and transmitting data. 2. Procedure Note: Refer to 4.5.7.5 through 4.5.7.8 for applicable test conditions. 2. Frequencies Below 4 kHz TIA-968-B, 5.2.1.4.1 1. Connect the EUT to the test circuit of Figure 9.18-1. 2. Select the 10 Hz to 4000 Hz bandpass filter. 3. Cause the EUT to transmit an output signal in accordance with TIA-968-B, subclause 4.5.7.6 and 4.5.7.7. 4. Record the voltmeter reading. 5. Repeat step (3) and step (4) for all possible states. Note: The remaining steps are only applicable to four-wire EUTs. 1. Connect the EUT to the test circuit of Figure 9.18-2. 2. Select the 10 Hz to 4000 Hz bandpass filter. 3. Repeat step (3) through step (5). Page 209 Telecommunications Industry Association TR41.9.1-10-05-002L 2. 100 Hz Bands in the Frequency Range 0.7 kHz to 4kHz TIA-968B, 4.5.6.1.2; 100 Hz Bands in the Frequency Range 4 kHz to 270 kHz TIA-968-B, 4.5.6.2.1 Note: See comments (1) and (2). 1. Connect the EUT to the test circuit of Figure 9.18-3. 2. Cause the EUT to transmit an output signal in accordance with subclause 4.5.7.6 and 4.5.7.7 of TIA-968-B. 3. Measure the rms voltage averaged over 100 ms with a bandwidth of 100 Hz. 4. Record the highest measured value and its associated frequency and any test results that exceed (-6) dBV for center frequencies in each 100 Hz band between 750 Hz and 3950 Hz. 5. Record the highest measured value and its associated frequency and any test results that exceed (-5) dBV for center frequencies in each 100 Hz band between 4.05 kHz and 4.60 kHz. 6. Compare the results with the allowed limit for each 100 Hz band having a center frequency between 4.60 kHz and 5.45 kHz, and record the measured value having the smallest margin relative to the allowed limit and its frequency. 7. Compare the results with the allowed limit for each 100 Hz band having a center frequency between 5.45 kHz and 59.12 kHz, and record the measured value having the smallest margin relative to the allowed limit and its frequency. 8. Compare the results with the allowed limit for each 100 Hz band having a center frequency between 59.12 kHz and 266 kHz, and record the measured value having the smallest margin relative to the allowed limit and its frequency. 9. Repeat step (2) through step (8) for all operating conditions. Note: The remaining steps are only applicable to four-wire EUTs. 10. Connect the EUT to the test circuit of Figure 9.18-4. 11. Repeat step (2) through step (9). Page 210 Telecommunications Industry Association TR41.9.1-10-05-002L 2. 8kHz bands Over the Frequency Range of 4 kHz to 270 kHz TIA-968-B, 4.5.6.2.2 ?? 5.2.1.4.2 1. Connect the EUT to the test circuit of Figure 9.18-3. 2. Cause the EUT to transmit an output signal in accordance with subclause 4.5.7.6 and 4.5.7.7 of TIA-968-B. 3. Measure the rms voltage averaged over 100 ms with a bandwidth of 8 kHz. 4. Compare the results with the allowed limit for each 8 kHz band having a center frequency between 8 kHz and 120 kHz, and record the measured value having the smallest margin relative to the allowed limit and its frequency. 5. Compare the results with the allowed limit for each 8 kHz band having a center frequency between 120 kHz to 266 kHz, and record the measured value having the smallest margin relative to the allowed limit and its frequency. 6. Repeat step (2) through step (5) for all operating conditions. Note: The remaining steps are only applicable to four-wire EUTs. 7. Connect the EUT to the test circuit of Figure 9.18-4. 8. Repeat step (2) through step (6). 2. RMS Voltages at Frequencies Above 270 kHz TIA-968-B, 4.5.6.2.3 Note: See comments (1), (2) and (3). 1. Connect the EUT to the test circuit of Figure 9.18-5. 2. Select the 270-kHz to 30-MHz bandpass filter. 3. Set the digital oscilloscope to provide: (a) 2 µs per sample; (b) Trigger at (-25) dBV; (c) Accumulate mode; Page 211 Telecommunications Industry Association TR41.9.1-10-05-002L (d) Vertical scale 0 mV to 100 mV full height. Note: If the baseline contains 1000 points then a single trace will take 2 ms. (4) Program the oscilloscope to accumulate 10 traces. (5) Cause the EUT to transmit an output signal in accordance with subclause 4.5.7.6 and 4.5.7.7. (6) Record the value of the largest peak measured and convert to Vrms by multiplying by 0.707. Note: The remaining steps are only applicable to four-wire EUTs. (7) Connect the EUT to the test circuit of Figure 9.18-6. (8) Repeat step (2) through step (6). 2. Peak Voltages at Frequencies Above 4 kHz TIA-968-B, 4.5.6.2.4 Note: See comments (1) and (2). 1. Connect the EUT to the test circuit Figure 9.18-5. 2. Select the 4 kHz to 30-MHz bandpass filter. 3. Set the digital oscilloscope to provide: (a) 2 microseconds (µs) per sample; (b) Trigger at 0.4 V peak; (c) Accumulate mode; (d) Vertical scale 0 V to 5 V full height. 4. Accumulate peak readings for a 10-second period. 5. Cause the EUT to transmit an output signal in accordance with subclauses 4.5.7.6 and 4.5.7.7 of TIA-968-B. 6. Record the value of the largest peak measured. Page 212 Telecommunications Industry Association TR41.9.1-10-05-002L Note: The remaining steps are only applicable to four-wire EUTs. 7. Connect the EUT to the test circuit of Figure 9.18-6. 8. Repeat step (2) through step (6). 2. Alternative Methods None suggested. 2. Suggested Test Data 1. Center frequencies measured or frequency band measured. 2. Voltage levels, measured or calculated. 3. Equipment state. 2. Comments 1. A quasi-random signal source may be used for testing. 2. See TIA-968-B, subclauses 4.5.7.5 through 4.5.7.8 further information. Figure 9.18-1. LADC Metallic 10 Hz to 4 kHz, T&R Figure 9.18-2. LADC Metallic 10 Hz to 4 kHz, T1 & R1 Note: The spectrum analyzer should provide a balanced input, or an isolation transformer should be used. Figure 9.18-3. LADC Metallic 700 Hz to 270 kHz, T&R Note: The spectrum analyzer should provide a balanced input, or an isolation transformer should be used. Page 213 Telecommunications Industry Association Figure 9.18-4. LADC Metallic 700 Hz to 270 kHz, T1&R1 1. The oscilloscope should provide a balanced input. 2. Refer to the procedure for selection of the appropriate bandpass filter. 3. Refer to the figures of clause 1 of TIA-968-B. Figure 9.18-5. LADC Metallic 270 kHz to 30 Mhz, T&R 1. The oscilloscope should provide a balanced input. 2. Refer to the procedure for selection of the appropriate bandpass filter. 3. Refer to the figures of clause 1 of TIA-968-B. Figure 9.18-6. LADC Metallic 270 kHz to 30 MHz, T1&R1 Page 214 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.43 Longitudinal Voltage 0.01 kHz to 6 MHz, LADC TIA-968-B, 5.2.1.4.2 1.43.1 Background The basis for these requirements is identical to that described in 9.18.1 except that the wire pair crosstalk characteristics are such that there is great crosstalk coupling of longitudinal voltages. Thus, there is a lower limit on both the in-band and out-of-band longitudinal LADC voltages than the metallic LADC voltages. 1.43.2 Purpose To verify that the EUT does not apply excessive longitudinal power to the network. 1.43.3 Equipment 1. Applicable loop simulator SEL#4. 2. Bandpass filter SEL#9. 3. Bandpass filter SEL#11. 4. Companion terminal equipment SEL#15. 5. Digital sampling storage oscilloscope SEL#24. 6. Spectrum Analyzer SEL#34. Note: Refer to subclause 5.5 for equipment details. 1.43.4 Equipment States Subject to Test Active and transmitting data. Note: Terminal equipment may require special attention to ensure it is properly configured for this test. For example, if the equipment would normally be connected to ac-power ground, cold-water-pipe ground, or if it has a metallic or partially metallic exposed surface, then these points are to be connected to the test ground plane. Similarly, if the EUT provides connections to other equipment through which ground may be introduced to the equipment, then these points are to be connected to the test ground plane. Equipment that does not contain any of these potential connections to ground is to be placed on a conductive plate which is connected to the test ground plane (see comment (3)); this applies to both non powered and acpowered equipment. Page 215 Telecommunications Industry Association TR41.9.1-10-05-002L 1.43.5 Procedure Note: Refer to subclause 4.5.7.5 to 4.5.7.8 for applicable test conditions. 1.43.6 Frequencies Below 4 kHz TIA-968-B, 4.5.6.3.1 ??5.2.1.4.2 1. Connect the EUT to the test circuit of Figure 9.19-1. 2. Cause the EUT to transmit an output signal in accordance with subclauses 4.5.7.6 and 4.5.7.7 of TIA-968-B. 3. Record the maximum spectrum analyzer reading in the test band. 4. Repeat step (2) and step (3) for all possible states. Note: The remaining steps are only applicable to four-wire EUTs. 5. Connect the EUT to the test circuit of Figure 9.19-2. 6. Repeat step (2) through step (4). Note: The measured result is to be corrected (+3.1) dB for the voltage divider relationship of the termination. 1.43.7 8 kHz Bands over the Frequency Range of 4 kHz to 270 kHz TIA-968-B, 4.5.6.3.2 ?? 5.2.1.4.2.3 1. Connect the EUT to the test circuit Figure 9.19-3. 2. Select R1=R2=150 ohms and R3=425 ohms. 3. Cause the EUT to transmit an output signal in accordance with subclause 4.5.7.6 and 4.5.7.7 of TIA-968-B. 4. Measure the rms voltage averaged over 100 ms with a bandwidth of 8 kHz covering the frequency range of 4 kHz to 16 kHz. Note: The measured result is to be corrected for the voltage divider relationship of the termination. Adjustment is (+1.4) dB. Page 216 Telecommunications Industry Association TR41.9.1-10-05-002L 5. Compare the results with the allowed limit for each 8 kHz band having a center frequency between 8 kHz and 12 kHz, and record the measured value having the smallest margin relative to the allowed limit and its frequency. 6. Select R1=R2=67.5 ohms and R3=56.3 ohms. 7. Cause the EUT to transmit an output signal in accordance with subclause 4.5.7.6 and 4.5.7.7 of TIA-968-B. 8. Measure the rms voltage averaged over 100 ms with a bandwidth of 8 kHz covering the frequency range of 8 kHz to 46 kHz. Note: The measured result is to be corrected for the voltage divider relationship of the termination. Adjustment is (+4.0) dB. 9. Compare the results with the allowed limit for each 8 kHz band having a center frequency between 12 kHz and 42 kHz, and record the measured value having the smallest margin relative to the allowed limit and its frequency. 10. Measure the rms voltage averaged over 100 ms with a bandwidth of 8 kHz covering the frequency range 38 kHz to 270 kHz. Note: The measured result is to be corrected for the voltage divider relationship of the termination. Adjustment is (+4.0) dB. 11. Record the highest measured value and its associated frequency and any test results that exceed ( 62) dBV for center frequencies in each 8 kHz band between 42 kHz and 266 kHz. 12. Repeat step (2) through step (11) for all operating conditions. Note: The remaining steps are only applicable to four-wire EUTs. 13. Connect the EUT to the test circuit of Figure 9.19-4. 14. Repeat step (2) through step (12) for all operating conditions. 1.43.8 RMS Voltages at Frequencies Above 270 kHz 4.5.6.3.3 ?? 5.2.1.4.2 1. Connect the EUT to the test circuit of Figure 9.19-5. 2. Select the 270 kHz to 6 MHz bandpass filter. Page 217 Telecommunications Industry Association TR41.9.1-10-05-002L 3. Set the digital oscilloscope to provide: (a) 2 microseconds (µs) per sample; (b) Trigger at (-25) dBV; (c) Accumulate mode; (d) Vertical scale 0 mV to 100 mV full height. Note: If the baseline contains 1000 points then a single trace will take 2 ms. (4) Program the oscilloscope to accumulate 10 traces. (5) Cause the EUT to transmit an output signal in accordance with subclauses 4.5.7.6 and 4.5.7.7 of TIA-968-B. (6) Record the value of the largest peak measured and convert to Vrms by multiplying by 0.707. Note: The remaining steps are only applicable to four-wire EUTs. (7) Connect the EUT to the test circuit of Figure 9.19-6. (8) Repeat step (2) through step (6). Note: The measured result of step (7) is to be corrected (+4) dB for the voltage divider relationship of the termination. 1.43.9 Alternative Methods None suggested. 1.43.10 Suggested Test Data 1. Center frequencies measured or frequency band measured. 2. Voltage levels, measured or calculated. Page 218 Telecommunications Industry Association TR41.9.1-10-05-002L 3. Equipment state. 1.43.11 Comments (1) Reference TIA-968-B, subclauses 4.5.7.5 through 4.5.7.8 for further information. (2) A pseudorandom signal source may be used for testing. (3) EUT that is not normally grounded should be set in its normal position directly on a conductive plate. It is recommended that the overall area of the conductive plate be at least 50% greater than that of the base of the EUT. This represents the closest proximity to ground that is likely to be encountered by the EUT. 1. Ensure proper operation of the EUT while the pair under test is not connected to the companion terminal equipment. 2. The 300 ohm resistors should be adequately matched. 3. Refer to the figures of clause 1 of TIA-968-B. Figure 9.19-1. LADC Longitudinal 10 Hz - 4 kHz, T&R 1. Ensure proper operation of the EUT while the pair under test is not connected to the companion terminal equipment. 2. The 300 ohm resistors should be adequately matched. 3. Refer to the figures of clause 1 of TIA-968-B. Figure 9.19-2. LADC Longitudinal 10 Hz to 4 kHz, T1 & R1 Page 219 Telecommunications Industry Association Page 220 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L Notes: (1) Ensure proper operation of the EUT while the pair under test is not connected to the companion terminal equipment. (2) The resistors R1 and R2 should be adequately matched. (3) Refer to the figures of clause 1 of TIA-968-B. Figure 9.19-3. LADC Longitudinal 4 kHz to 270 kHz, T & R 1. Ensure proper operation of the EUT while the pair under test is not connected to the companion terminal equipment. 2. The resistors R1 and R2 should be adequately matched. 3. Refer to the figures of clause 1 of TIA-968-B. Figure 9.19-4. LADC Longitudinal 4 kHz to 270 kHz, T1 & R1 Page 221 Telecommunications Industry Association TR41.9.1-10-05-002L 1. Ensure proper operation of the EUT while the pair under test is not connected to the companion terminal equipment. 2. The 67.5 ohm resistors should be adequately matched. 3. Refer to the figures of clause 1 of TIA-968-B. Figure 9.19-5. LADC Longitudinal 270 kHz to 6 MHz, T & R 1. Ensure proper operation of the EUT while the pair under test is not connected to the companion terminal equipment. 2. The 67.5 ohm resistors should be adequately matched. 3. Refer to the figures of clause 1 of TIA-968-B. Figure 9.19-6. LADC Longitudinal 270 kHz to 6 Mhz, T1 & R1 Page 222 Telecommunications Industry Association Page 223 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.44 Pulse Repetition Rate, Subrate/PSDS, TIA-968-B, 5.2.2.1.1 1.44.1 Background The transmitted pulse repetition rate needs to be the same as the rate used to create the pulse template. This ensures proper pulse width for comparison with the pulse templates defined in TIA-968-B, 5.2.2.1.1 for Subrate signaling and 5.2.2.1.1 for PSDS Type II or III signaling. 1.44.2 Purpose To verify that the EUT will synchronize its output clock rate as required. Subrate equipment should synchronize with the network clock rate and PSDS equipment should synchronize with its internal setting. 1.44.3 Equipment 1. Data generator SEL#18. 2. Spectrum analyzer SEL#34. Note: Refer to subclause 5.5 for equipment details. 1.44.4 Equipment States Subject to Test The EUT should be active and transmitting a digital signal. This test should be performed at each of the data rates at which the equipment under test is capable of operating. 1.44.5 Procedure 1. Connect the EUT to the test circuit of Figure 9.20-1. Both the transmit pair and receive pair should be terminated with 135 ohms. (a) For Subrate equipment, transmit a digital signal into the receive tip and ring leads of the EUT at the appropriate data rate. (b) For PSDS equipment, configure the EUT to generate the appropriate data rate for test. Page 224 Telecommunications Industry Association TR41.9.1-10-05-002L 2. Measure the resultant pulse rate on the transmit tip and ring leads. 3. Verify that the output pulse rate of the EUT is the same as the data rate input on the receive tip and ring leads for Subrate equipment or as configured for PSDS equipment. 4. Repeat steps (2) through (4) as necessary for each data rate supported by the EUT. 1.44.6 Alternative Method 1. Performance of this test is equally possible with a dual-trace oscilloscope by connecting it to the equipment so that one channel displays the signal input to the equipment under test while the other channel displays the output signal. The output of the equipment under test is synchronous with the input if there is no horizontal movement (walking) of the transmitted pulse display in relation to the received pulse display when the scope is set to trigger on the received signal. 1.44.7 Suggested Test Data The measured pulse repetition rate for each available data rate. 1.44.8 Comment If a pulse counter is used in place of the spectrum analyzer to make this measurement, ensure that the measured output consists of an all-ones signal so that a proper reading is taken. 1. The spectrum analyzer should provide a balanced input. 2. For PSDS Type II and III equipment, T1 and R1 leads and the Data Generator are not used. Figure 9.20-1. Subrate, Pulse Repetition Rate Page 225 Telecommunications Industry Association Page 226 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.45 Encoded Analog Content TIA-968-B 4.5 1.45.1 Background Encoded analog content refers to the digital representation of analog signals encoded in a digital bit stream. Encoding consists of sampling the analog waveform at timed intervals and assigning a unique binary code to represent each quantized amplitude. These binary codes, when decoded, are then used to create an analog waveform that represents the original. Normally, decoding results in the same analog level for each sample that was originally encoded. This process is known as zero-level encoding and decoding of an analog waveform. Encoded analog limits ensure that analog signal power and billing protection requirements are met at the digital interface so that no further analog limitations are required downstream where digital to analog conversion and connection to the analog network takes place. If not limited, the analog signals could crosstalk into other pairs in the same cable or overload telephone company frequency division multiplex systems (carrier systems). Generally, analog levels decoded by a zero-level decoder are 3 dB lower than levels from analog terminal equipment. Actually, the limit is the same for both cases at the telephone company CO, but analog loops have a nominal 3 dB loss while digital facilities are lossless in analog terms. Digital terminal equipment can be designed to assure that encoded analog signal power requirements are met. If not, it is to be connected to equipment that either is approved for compliance with the encoded analog limits or is used under a condition that encoded analog content will not be used or will be properly adjusted. 1.45.2 Purpose To verify the maximum equivalent power of the encoded analog content of the transmitted digital signal. 1.45.3 Equipment 1. Companion terminal equipment SEL#15. 2. Multiplexer/demultiplexer SEL#32. 3. True rms AC voltmeter SEL#40. Page 227 Telecommunications Industry Association TR41.9.1-10-05-002L Note: Refer to subclause 5.5 for equipment details. 1.45.4 Equipment States Subject to Test The EUT is to be active and transmitting encoded analog signals. 1.45.5 Procedure 1. Connect the EUT to the test circuit of Figure 9.21-1. As shown, two types of signals may be transmitted: 1. Internally generated signals that are generated directly in digital form but which are intended for eventual conversion to analog form; 2. Internally generated analog signals that are converted to digital format for eventual reconversion to analog form. 2. For signals of type (a) or type (b) as described above, cause the equipment to generate each of the possible signals. 3. Record the power of each of the transmitted signals as measured at the output of the zerolevel decoder or companion terminal equipment. The recorded level should be the maximum obtainable level when averaged over any 3-second interval. 1.45.6 Alternative Methods (1) Connect the EUT to the test circuit of Figure 9.21-1 and replace the true rms AC voltmeter with a signal analyzer (SEL#56). (2) Set the signal analyzer to measure the following: (a) Signal level in dBm, 600 ohms. (b) Averaging over 3 second. (c) Band pass power in the frequency range of 200 Hz to 4 kHz band. Note: Signal Analyzer should provide a balanced input, or an isolation transformer may be used. Page 228 Telecommunications Industry Association TR41.9.1-10-05-002L (3) For signals of type (a) or type (b) as described in subclause 9.21.5, cause the equipment to generate each of the possible signals. (4) Measure and record the maximum signal power level in dBm. (5) Repeat step (2) and step (3) for other internally generated signals. 1.45.7 Suggested Test Data The signal measured and the power reading measured. 1.45.8 Comments 1. The measurement is to be in dBm with respect to 600 ohms. 2. Both the network control signals and all internally generated signals is to be measured. 3. For readings requiring averaging, a meter incorporating this function may be used to make the measurement, or the average may be calculated using the maximum duty cycle within the 3-second time period. 4. The test procedures in this subclause apply to interfaces that are covered in TIA-968-B subclauses 4.5.8.1.2, 4.5.8.2.5, 4.5.8.3 and 4.5.8.4. Page 229 Telecommunications Industry Association Note: For PSDS type II, III and BRA-U equipment, T1 and R1 leads are not used. Figure 9.21-1. Encoded Analog Content Page 230 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.46 Equivalent PSD For Maximum Output, Subrate – TIA-968-B, 5.2.2.1.4 1.46.1 Background This subclause provides a test procedure to measure power spectral density (PSD) against the alternate subrate requirements specified in TIA-968-B, subclause 5.2.2.1.4. The PSD requirements were established as an alternate method to the subrate pulse requirements to minimize crosstalk interference with other equipment that share the same cable binder. Crosstalk interference is widely recognized as a form of third party harm. 1.46.2 Purpose To verify that the PSDs generated by subrate devices are below the established masks (as applicable). 1.46.3 Equipment 1. Spectrum analyzer SEL# 57. 2. Data generator SEL# 18. 3. 135:50 ohm balun transformer SEL# 65. Note: Refer to subclause 5.5 for equipment details. 1.46.4 Equipment States Subject to Test The EUT is to be active and continuously transmitting pseudo-random test pattern at each applicable line baud rate. Page 231 Telecommunications Industry Association TR41.9.1-10-05-002L 1.46.5 Procedure 1. Connect the EUT to the test circuit of Figure 9.22-1. 2. Configure the EUT to transmit a pseudo-random test pattern at the desired baud rate. 3. Measure and record the PSD on the spectrum analyzer with the following settings: (a) Set the RES BW to the closest value less than 0.1 times the baud rate (or lower if desired). (b) Set the VIDEO BW and to 0.1 times the resolution bandwidth (or lower). (c) dB/div: 10 dB (d) Reference level: as required to capture the entire PSD (e) Attenuation or range: Set for minimum without overload (f) Start frequency: ½ the EUT baud rate (g) Stop frequency: 20 times the baud rate unless 20 times the baud rate is less than 80 kHz, in which case set the stop frequency to 80 kHz. (h) Marker Function: Noise dBm/Hz 4. Repeat Step (2) and Step (3) for all baud rates at which the equipment is capable of operating. 1.46.6 Alternative Methods None suggested. 1.46.7 Suggested Test Data 1. Plots of the PSD for each baud rate with the limit line shown on each graph 1.46.8 Comments 1. The PSD measurements should be noise measurements in dBm/Hz. Page 232 Telecommunications Industry Association TR41.9.1-10-05-002L 2. Take into account applicable correction factors for the balun over the bandwidth of the measurement. Note: The value of R is to be selected such that R plus the source impedance of the data generator will equal 135 ohms. Figure 9.22-1. Subrate Signal Power Page 233 Telecommunications Industry Association Page 234 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.47 Average Power, Subrate, Non-Secondary Channel Rates, Secondary Channel Rates TIA-968-B, 5.2.2.1.5 1.47.1 Background The signal power of subrate devices is limited to minimize crosstalk interference with other equipment that share the same cable binder. Crosstalk interference is widely recognized as a form of third party harm. 1.47.2 Purpose To verify that the signal power level transmitted to the network is properly limited. 1.47.3 Equipment 1. True rms AC voltmeter SEL# 41. (2) Data generator SEL# 18. 1. 135 ohm, 1 %, non-inductive resistor. Note: Refer to subclause 5.5 for equipment details. 1.47.4 Equipment States Subject to Test The EUT is to be active and continuously transmitting a pseudo-random test pattern at each applicable line rate. 1.47.5 Procedure 1. Connect the EUT to the test circuit of Figure 9.23-1. Page 235 Telecommunications Industry Association TR41.9.1-10-05-002L 2. Configure the EUT to transmit a pseudo-random test pattern at the desired line rate. 3. Measure and record the signal power level in dBm. Repeat Step (2) and Step (3) for all pulse rates at which the equipment is capable of operating. 1.47.6 Alternative Methods The total signal power may also be calculated by integrating the PSD over the operating band. This task consists of measuring the PSD over the operating band using a resolution bandwidth of 0.1 times the line rate at discrete frequencies with a stepped interval of 0.1 times the line rate. The individual PSD readings are then converted to power readings by multiplying the PSD (in terms of watts/Hz) by the resolution bandwidth used. This results in a power level for each resolution bandwidth window. These are then summed over the operating band to give the total power. The PSD measurement procedure is given in 9.22.4. 1.47.7 Suggested Test Data 1. Signal power level 2. (2) Line rate as applicable 1.47.8 Comments 1. If the AC voltmeter has its dBm scale referenced to 600 ohm, correct the measurement to account for the measurement impedance of 135 ohm. Note: The value of R is to be selected such that R plus the source impedance of the data generator will equal 135 ohm. Figure 9.23-1. Subrate Signal Power Page 236 Telecommunications Industry Association Page 237 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.48 Pulse Template, Subrate/PSDS TIA-968-B, 5.2.2.1.7 1.48.1 Background Pulse templates, one for each data rate, define the pulse shape needed to minimize the risk of crosstalk interference in telephone company transmission facilities. The single pole filter, which provides high frequency roll-off, and the specific limits in the vicinity of 28 kHz and 76 kHz protect other services using the same telephone company cable. Similarly, the pulse amplitude limit for the 9.6 kilobits per second (kb/s) and 12.8 kilobits per second (kb/s) data rates are less than for other subrates because of the sensitivity of certain loop transmission systems to crosstalk interference at the frequencies generated. 1.48.2 Purpose To verify the pulse shape of the digital signal at the output of the EUT. 1.48.3 Equipment 1. Data generator SEL#18. 2. Digital sampling storage oscilloscope SEL#24. Note: Refer to subclause 5.5 for equipment details. 1.48.4 Equipment States Subject to Test The EUT is to be active and transmitting a data pattern which allows the recording of an isolated pulse. An isolated pulse is a single pulse without leading or trailing pulses (i.e., a bit pattern of 010). The number of leading and trailing zeros which it is possible to transmit may vary from equipment to equipment; however, at least one leading and one trailing zero is necessary, and it is desirable to make the measurement with as many as seven leading and seven trailing zeros. 1.48.5 Procedure 1. Connect the EUT to the test circuit of Figure 9.24-1. Page 238 Telecommunications Industry Association TR41.9.1-10-05-002L 2. Cause the equipment under test to transmit a digital signal which will allow the capture of an isolated pulse. 3. Record a single positive pulse on the oscilloscope, and compare the pulse to the criteria. 4. Record a single negative pulse on the oscilloscope, and compare the pulse shape to the criteria. 5. Repeat Step (3) and Step (4) for all pulse rates at which the equipment is capable of operating. 1.48.6 Alternative Method None suggested. 1.48.7 Suggested Test Data 1. A photograph or drawing of the pulse. 2. Test state. 3. Data rate. 1.48.8 Comments 1. A non-storage oscilloscope may be used in place of the storage oscilloscope. A repetitive pattern of the isolated pulse signal should be transmitted in order to measure the pulse shape of a single pulse (i.e., a bit pattern of 010101... ). 2. See Appendix A.1 for more information concerning the subrate and PSD pulse templates. 3. Configure PSDS Type II and III equipment to transmit on a stand alone basis. 4. PSDS Type I is evaluated in the same manner as 56 kilobits per second (kb/s) subrate equipment. Page 239 Telecommunications Industry Association Page 240 TR41.9.1-10-05-002L Telecommunications Industry Association 1. The oscilloscope should provide a balanced input. 2. PSDS Types II and III equipment do not have T1 and R1 leads. Figure 9.24-1. Subrate and PSDS, Pulse Template. Page 241 TR41.9.1-10-05-002L Telecommunications Industry Association Page 242 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.49 Average Power, Subrate TIA-968-B, 5.2.2.1.8 1.49.1 Background The long term average power needs to be limited to prevent crosstalk. 1.49.2 Purpose To verify the total output power of the digital signal transmitted by the equipment under test. 1.49.3 Equipment 1. Data generator SEL#18. 2. True rms AC voltmeter SEL#41. Note: Refer to subclause 5.5 for equipment details. 1.49.4 Equipment States Subject to Test The EUT is to be active and transmitting a pseudorandom digital signal. 1.49.5 Procedure 1. Connect the EUT to the test circuit of Figure 9.25-1. 2. Arrange the EUT to transmit a pseudorandom signal sequence (see Comment (3)). 3. Measure the power of the transmitted signal. 4. Repeat the test at all of the transmission rates of the EUT. 1.49.6 Alternative Method None suggested. Page 243 Telecommunications Industry Association TR41.9.1-10-05-002L 1.49.7 Suggested Test Data The measured signal power in dBm for each transmission rate and operating state of the EUT. 1.49.8 Comments 1. Note that the criteria is in dBm with reference to 135 ohms. Some measuring instruments use different reference impedances. Readings made on instruments using reference impedances other than 135 ohms should be corrected. 2. In order to evaluate the long term average level of the signal, measurements using a 3second averaging time are appropriate. 3. In some cases, it may be necessary to use an external digital source. If the EUT does not allow the transmission of the random test signal, the test may be performed with an allones signal being transmitted. When transmitting a digital signal of all-ones, the average signal power can be calculated by subtracting the averaging factor (3 dB) from the measured signal power. 4. A spectrum analyzer may be used to measure the individual spectral components of the signal, and the sum of the powers of these signals may be taken. Note: The voltmeter should provide a balanced input. Figure 9.25-1. Subrate, Average Power Page 244 Telecommunications Industry Association Page 245 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.50 Pulse Repetition Rate, 1.544 Mb/s TIA-968-B, 5.2.4.1 1.50.1 Background Improper pulse rates cause interference with other users in higher level bit streams. 1.50.2 Purpose To verify the free-running pulse repetition rate of the EUT. 1.50.3 Equipment 1. Data generator SEL#18. 2. Spectrum analyzer SEL#34. Note: Refer to subclause 5.5 for equipment details. 1.50.4 Equipment States Subject to Test The EUT is to be active and transmitting a free running signal. 1.50.5 Procedure 1. Connect the EUT to the test circuit of Figure 9.26-1. Both the transmit pair and the receive pair should be terminated in the proper resistive loads. 2. Arrange the equipment in accordance with the instruction manual so that it generates a free-running signal. 3. Measure the resultant pulse repetition rate. 1.50.6 Alternative Methods Page 246 Telecommunications Industry Association TR41.9.1-10-05-002L None suggested. 1.50.7 Suggested Test Data 1. Type of signal. 2. Measured pulse repetition rate. 1.50.8 Comments 1. As many "ones" as possible should be transmitted while making the measurement to increase the energy of the signal at the pulse frequency. 2. As an alternative, use a PCM decoder which provides a 1.544 MHz clock which is derived from the output of the EUT by the decoder. Figure 9.26-1. 1.544 megabits per second (Mb/s), Pulse Repetition Rate Page 247 Telecommunications Industry Association Page 248 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.51 Pulse Template, 1.544 Mb/s TIA-968-B, 5.2.4.2 1.51.1 Background Line Build Out (LBO) controls the pulse shape in order to present a compatible signal input for some T1 line repeaters or to limit crosstalk on non-repeatered route junctions. Subclause 5.2.4.2 requires that the equipment provide an option to set the amplitude of the T1 signal presented to the network consistent with three values of LBO. The carrier advises the customer on the LBO setting at the time of installation. LBO synthesizes cable loss within the terminal equipment and is expressed as a minimum loss at 772 kHz. LBO’s of 0 dB, 7.5 dB, and 15 dB correspond to the Pulse Template Options of A, B, and C respectively. Testing and showing compliance with the Pulse Template Options described in subclause 5.2.4.2 also satisfies the requirements in subclause 5.2.4.2 for the Adjustment of Signal Voltage. 1.51.2 Purpose To verify that the equipment is capable of delivering the Option A, B, and C output pulses and that the rise and fall times and the amplitude of an isolated pulse meets the pulse template criteria. 1.51.3 Equipment 1. DS1 transmission set (SEL#25) if required. 2. Digital sampling storage oscilloscope (SEL#24). Note: Refer to subclause 5.5 for equipment details. 1.51.4 Equipment States Subject to Test The EUT is to be active and transmitting a data pattern which allows for the recording of an isolated pulse. An isolated pulse is a single pulse without leading or trailing pulses. The number of leading and trailing zeros that is possible to transmit may vary from equipment to equipment. However, at least four leading and one trailing zero is necessary to make an accurate measurement. The 1-in-8 test pattern satisfies the requirement for leading and trailing zeros. 1.51.5 Procedure Page 249 Telecommunications Industry Association TR41.9.1-10-05-002L 1. Connect the EUT to the test circuit of Figure 9.27-1. 2. Verify that the output pulse options are selectable at the time of installation, and select output pulse option "A" (0 dB loss at 772 kHz). 3. Cause the equipment under test to generate a pattern, which will allow for the capture of an isolated pulse. This may be achieved by putting the equipment in loopback and using the DS1 transmission set to send a suitable test pattern or by causing the equipment to send the test pattern using its internal generator. 4. Record a single positive pulse on the oscilloscope, and compare the pulse shape to the template criteria. 5. Record a single negative pulse on the oscilloscope, and compare the pulse shape to the template criteria. 6. Repeat Step (3) through Step (5) for output pulse options "B" (7.5 dB loss at 772 kHz) and "C" (15 dB loss at 772 kHz). 1.51.6 Alternative Methods If the equipment is capable of generating the test pattern internally and can operate using internal timing, then the test may be performed without the DS1 transmission set. In this case, terminate the receive pair with a 100 ohm resistive load. 1.51.7 Suggested Test Data 1. The pulse option. 2. Plots of the isolated pulses relative to the pulse mask templates. 1.51.8 Comments 1. A non-storage oscilloscope may be used in place of the storage oscilloscope. A repetitive pattern of the isolated pulse signal should be transmitted in order to make the measurement. In this situation, an unframed signal or loopback of a controlled input signal may be transmitted to capture the proper pulse. 2. See Appendix A.2 for more information concerning the 1.544 megabits per second (Mb/s) pulse templates. Page 250 Telecommunications Industry Association TR41.9.1-10-05-002L 3. The LBO of the DS1 transmission set, if used, should be set to a minimum of 15 dB to minimize coupling into the equipment’s transmit pair to minimize distorting the EUT’s signal. Note: The oscilloscope should provide a high-impedance balanced input. Figure 9.27-1. 1.544 Mb/s, Pulse Template connection diagram Page 251 Telecommunications Industry Association Page 252 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.52 Output Power, 1.544 Mb/s TIA-968-B, 5.2.4.4 1.52.1 Background The long-term average power for pulse option "A" (0 dB loss at 772 kHz)is limited to control crosstalk interference. The limitation is in the 3-kHz band around the 772-kHz envelope of the bipolar signal and the 1.544-MHz pulse repetition rate where the majority of the energy of an allones unframed signal is located. 1.52.2 Purpose To verify the output power of an all-ones unframed digital signal in the 3 kHz bands centered at 772 kHz and 1.544 MHz is within the stated limitations. 1.52.3 Equipment 1. Data generator SEL#18. 2. Spectrum analyzer SEL#34. Note: Refer to subclause 5.5 for equipment details. 1.52.4 Equipment States Subject to Test Active and transmitting an unframed all "ones" digital signal. If transmission of an unframed all "ones" signal is not possible, then the readings taken are to be corrected for the data pattern that is transmitted. This correction is covered in the alternative procedure of subclause 14.2.4.6. 1.52.5 Procedure 1. Connect the EUT to the test circuit of Figure 9.28-1 and select pulse option "A" (0 dB loss at 772 kHz). 2. Cause the equipment to transmit the unframed all “ones” digital signal. 3. With a measurement bandwidth of 3 kHz, measure the signal power at 772 kHz. Page 253 Telecommunications Industry Association TR41.9.1-10-05-002L 4. With a measurement bandwidth of 3 kHz, measure the signal power at 1.544 MHz. 1.52.6 Alternative Method The following method of measurement may be used when an unframed all-ones condition cannot be achieved. The equipment should be configured to be transmitting idle channels with a stable bit pattern; that is, no signal input to any channel. The transmitted pulse level should be set for option "A." Note the pulse density of the transmitted signal. This may be determined by examination of the transmitted bit stream. 1. Connect the EUT to the test circuit of Figure 9.28-1, and measure the amplitude of a positive and negative pulse. These pulses should have both leading and trailing pulses. 2. Calculate the power at 772 kHz in dBm using the formula: Where V is the arithmetic average of the absolute value of the pulse amplitudes found in Step (2). 4. Measure the signal power at 1.544 MHz using the method described in subclause 14.2.4.6 and calculate the all-ones power by adding the appropriate correction factor for the ones density of the transmitted signal from Table 9.28-1. Page 254 Telecommunications Industry Association TR41.9.1-10-05-002L 6. Table 9.28-1. Correction Factors for 1.544 megabits per second (Mb/s) Output Power Ones Correction Factor (dB) Density (%) 12.5 18.1 25.0 12.0 37.5 8.5 50.0 6.0 62.5 4.1 75.0 2.5 87.5 1.1 100.0 0.0 1.52.7 Suggested Test Data The measured power at 772 kHz and at 1.544 MHz in dBm with respect to 100 ohms. 1.52.8 Comments 1. The reading is to be in dBm referenced to 100 ohms. If the measuring instrument uses a reference impedance other than 100 ohms, the measurement is to be corrected. 2. A variable bandpass filter and true rms voltmeter may be used in place of the spectrum analyzer to make the measurement. 3. A frequency selective voltmeter may be used in place of the spectrum analyzer to make the measurement. Page 255 Telecommunications Industry Association TR41.9.1-10-05-002L 4. For accuracy, the 3 kHz bandpass measurement should be made with a filter having a sharp rolloff; however, the filter should not cause attenuation of the signal being measured. If a measurement bandwidth of 3 kHz is not obtainable, care should be taken that signal power in the desired band is not excluded for measurement bandwidths less than 3 kHz and that additional signals are not included in the measurement for bandwidths greater that 3 kHz. Page 256 Telecommunications Industry Association Page 257 TR41.9.1-10-05-002L Telecommunications Industry Association Note : The spectrum analyzer should provide a high-impedance, balanced input. Figure 9.28-1. 1.544 megabits per second (Mb/s), Output Power Page 258 TR41.9.1-10-05-002L Telecommunications Industry Association Page 259 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.53 Unequipped Sub-rate Channels TIA-968-B, 5.2.4.6 1.53.1 Background For connections to 1.544 megabits per second (Mbps) digital services, the permissible code words for unequipped µ255 encoded sub-rate channels of terminal equipment connected to 1.544 Mbps digital services, including ISDN PRA, are limited to those corresponding to signals of either polarity, of magnitude equal to or less than X48, where code word Xn is derived by: Xn = (255 - n) base 2 -Xn = (127 - n) base 2 1.53.2 Purpose To verify that the equipment complies with the requirements of this subclause under all operating conditions. 1.53.3 Equipment None suggested. 1.53.4 Equipment States Subject to Test Not applicable. 1.53.5 Procedure None suggested. 1.53.6 Alternative Methods None suggested. 1.53.7 Suggested Test Data Page 260 Telecommunications Industry Association TR41.9.1-10-05-002L Provide an attestation that states that the design of the EUT complies with the requirement of this subclause under all operating conditions. 1.53.8 Comments None suggested. Page 261 Telecommunications Industry Association Page 262 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.54 Conditioning ADSL EUT to Transmit Continuously 1.54.1 9.30.1 General This subclause provides a suggested test procedure to measure aggregate signal power, power spectral density (PSD), and longitudinal output voltage (LOV) for ADSL modems (ADSL ATUR or similar CPE) against the applicable requirements specified in ANSI Standard TIA-968-B2002 including requirements up to and including those set out in TIA-968-B-3. 1.54.2 9.30.2 Conditioning the EUT to Transmit Continuously To properly measure aggregate signal power, PSD, and LOV, condition the EUT to transmit at its highest signal power level and line rate as allowed by the respective PSD mask without a sustained connection to companion equipment. The method of testing with a companion device is impractical for ADSL equipment since the companion (ATU-C) equipment may present excessively high signal levels at frequencies at which the upstream PSD mask demands very low PSD levels. The amount of attenuation required to reduce the companion equipment’s signals below the upstream mask would be excessive to permit the link to come up at the maximum upstream line rate. This is because ADSL equipment automatically reduces the line rate over long loops to maintain an acceptable level of performance. Test ADSL modems that support extended upstream operation against all of the spectral masks for all the operational modes that they support. The extended upstream mask 1 (TIA-968-B-3, 4.5.9.1.3) should be used for ADSL2+. There are two possible methods to achieve the required state for the ADSL modem. One method involves a test mode whereby the EUT’s transmitter is forced to enter the showtime state, at a maximum PSD level and line rate allowed by the PSD mask, without going through a training sequence. Showtime refers to the state where the ADSL modem is transmitting a pseudo-random data pattern continuously. The other technique first involves bringing the link up over an artificial line whose characteristics effectively force the EUT into its maximum signal power and line rate allowed by the PSD mask. Next, the EUT is strapped or conditioned to disable retrains so that once the showtime state has been achieved, the EUT may be disconnected from the artificial line and connected to a 100 ohm measurement termination. The artificial line may be either a commercial telephone line simulator or a simple 100 ohm balanced attenuator pad. In either case, the amount of through transmission attenuation is set to maximize the EUT’s transmit power and bandwidth subject to the PSD mask constraints. This is necessary as most ATU-R’s utilize an adaptive transmit power scheme where power is cut back under short loop conditions. By the same token, if the line attenuation is excessive, then the link will not have sufficient margin to come up at the desired line rate. The amount of line attenuation will vary from one vendor’s CPE to another and even with the same CPE if the start up margin is changed. Page 263 Telecommunications Industry Association TR41.9.1-10-05-002L 9.31 Total Average Power, ADSL Terminal Equipment TIA-968-B-3, 5.3.2.1.1, 5.3.3.1.1, 5.3.5.2.1 1.54.3 9.31.1 Background The aggregate signal power, or total power, of the ADSL modem is limited to minimize near end crosstalk (NEXT) with other DSL systems that share the same cable binder. Crosstalk is widely recognized as a form of third party harm and represents the principal impairment to many DSL systems. 1.54.4 9.31.2 Purpose To verify that the signal power level transmitted to the network is properly limited. 1.54.5 9.31.3 Equipment 1. True rms AC voltmeter SEL#41. 2. 100 ohm, 1 %, non-inductive resistor. Note: Refer to subclause 5.5 for equipment details. 1.54.6 9.31.4 Equipment States Subject to Test Transmitting continuously at its highest signal power and upstream line data rate allowed by the PSD mask. For ADSL modems that support extended upstream operation, consider each supported Extended Upstream [EU] mask number. 1.54.7 9.31.5 Procedure 1. Condition the EUT to transmit at it highest upstream signal power level and line rate as described in 9.31.2. 2. Connect the EUT to the test circuit of Figure 9.31-1. Page 264 Telecommunications Industry Association TR41.9.1-10-05-002L 3. Measure and record the signal power level in dBm. The level should be averaged over a time span of at least 10 seconds if shorter term variations are observed. 1.54.8 9.31.6 Alternative Methods The total signal power may also be calculated by integrating the PSD over the operating band. This task consists of measuring the PSD over the operating band using a 10 kHz resolution bandwidth at discrete frequencies with a stepped interval of 10 kHz. The individual PSD readings are then converted to power readings by multiplying the PSD (in terms of watts/Hz) by the 10 kHz resolution bandwidth. This results in a power level for each 10 kHz window. These are then summed over the operating band to give the total power. The PSD measurement procedure is given in 9.32.5. 1.54.9 9.31.7 Suggested Test Data 1. Signal Power Level. 2. Line Data Rate and Baud Rate if applicable. 1.54.10 9.31.8 Comments If the AC voltmeter has its dBm scale referenced to 600 ohms, then a use a correction factor of 7.8 dB added to the displayed reading to account for the measurement impedance of 100 ohms. It is recommended that the voltmeter provide a high-impedance balanced input particularly if the EUT has intentional paths to ground. Figure 9.31-1. Average Signal Power 9.31Power Spectral Density, ADSL Terminal Equipment TIA-968-B, 5.3.2.1.2, 5.3.3.1.1??, 5.3.5.2.2 Page 265 Telecommunications Industry Association 1.54.11 TR41.9.1-10-05-002L 9.32.1 Background As is the case for the ADSL modem’s total power, its PSD is limited to minimize crosstalk. PSD is limited by the imposition of a PSD mask, which specifies a limit as a function of frequency. The mask permits a reasonable level in the operating band while restricting the ADSL modem’s PSD below the operating band to protect POTS and above the operating band both to minimize interference both with the downstream spectrum as well as other DSL systems potentially affected by crosstalk. The mask presents measurement challenges because it specifies such a broad range of signal levels, which can’t practically be made in a single sweep due to limitations in the spectrum analyzer’s dynamic range. For this reason and resolution bandwidth considerations, the mask is broken into segments. Either low-pass or high-pass filtering techniques are employed, as necessary, to allow the spectrum analyzer to effectively measure low PSD levels in the presence of high PSD level conditions associated with the operating band. 1.54.12 9.32.2 Purpose To verify that the PSD is below the mask. 1.54.13 9.32.3 Equipment 1. Spectrum analyzer SEL#57. 2. 100 ohm, 1 % non-inductive resistor. 3. Differential amplifier with 10X passive probe set and built in LPF SEL#58. 4. 100:50 ohm balun transformer SEL#59. 5. 10 dB, 50 ohm pad SEL#60 6. 500 kHz High-Pass Filter SEL#61 Note: Refer to subclause 5.5 for equipment details. 1.54.14 9.32.4 Equipment States Subject to Test Page 266 Telecommunications Industry Association TR41.9.1-10-05-002L Transmitting continuously at its highest signal power and upstream line data rate allowed by the PSD mask. For ADSL modems that support extended upstream operation, consider each supported EU mask number. 1.54.15 9.32.5 Procedure In this document the criteria frequency range has been divided into four segments. The number of segments chosen is dependent upon the capabilities of the test equipment. Two test procedures have been provided for the fourth segment. Therefore the test procedure is broken down into five subclauses. Each frequency point in the operating band (corresponding to a measurement in a single resolution bandwidth) of a PSD should be measured by averaging the power in the resolution bandwidth of that frequency point for a time period of at least 2.0 seconds. For a frequency swept measurement device this means setting the sweep time in seconds equal to at least 2 times the number of frequency points. An instrument that has a swept average feature may be used with a faster single sweep if multiple sweeps are averaged to yield a minimum 2 second measurement time. Note - This 2.0 second time period is based on; A statistical derivation demonstrating that measurement of the average power in a given resolution bandwidth within 0.1 dB accuracy with 99% confidence requires observation of about 9,000 transmitted symbols and, The slowest common signal is an ADSL tone which is at a 4 kHz rate. A faster measurement may be obtained using a time domain measurement device as used in the examples provided. Take a sufficient number of samples to ensure an acceptable level of precision. 1.54.15.1 9.32.5.1 Procedure for Segment 1 1. Condition the EUT to transmit continuously as described in subclause 9.30.2. 2. Connect the EUT to the test circuit of Figure 9.32-1. 3. Set the differential amplifier for unity gain and a low-pass cut-off frequency of 10 kHz. Page 267 Telecommunications Industry Association TR41.9.1-10-05-002L 4. Set the spectrum analyzer as follows: Resolution bandwidth (RBW): 100 Hz Video bandwidth: 3 Hz Attenuation or range: Set for minimum without overload Reference level: (-40) dBm dB/div: 10 dB Marker Function: Noise dBm/Hz Limit test: On with limit line programmed with the mask’s peak limit Start frequency: 200 Hz Stop frequency: 4000 Hz Measure and record the PSD over the first segment of the mask, which covers the voice frequency band. For extended rate ADSL modems, repeat steps 1-5 for each supported EU mask. Note: Adjust the PSD readings by a net correction factor of 17 dB derived from the 10X probe which introduces 20 dB of loss and the 100:50 ohm impedance correction factor of -3 dB. The resistor value in Figure 9.32-1 is in ohms. 1.54.15.2 9.32.5.2 Procedure for Segment 2 1. Condition the EUT to transmit continuously as described in 9.30.2. 2. Connect the EUT to the test circuit of Figure 9.32-1. 3. Set the differential amplifier for unity gain with no filtering 4. Set the spectrum analyzer as follows: Resolution bandwidth: 1 kHz Video bandwidth: 30 Hz Attenuation or range: Set for minimum without overload Reference level: (-20) dBm dB/div: 10 dB Marker Function: Noise dBm/Hz Limit test: On with limit line programmed with the mask’s peak limit Start frequency: 4 kHz Page 268 Telecommunications Industry Association TR41.9.1-10-05-002L Stop frequency: 26 kHz Measure and record the PSD over the second segment of the mask, which covers the frequencies between the voice band and the ADSL operating band. For extended rate ADSL modems, repeat steps 1-5 for each supported EU mask. 1.54.15.3 9.32.5.3 Procedure for Segment 3 1. Condition the EUT to transmit continuously as described in 9.30.2. 2. Connect the EUT to the test circuit of Figure 9.32-4. 3. Set the spectrum analyzer as follows: Resolution bandwidth: 10 kHz Video bandwidth: 300 Hz Attenuation or range: Set for minimum without overload Reference level: (-20) dBm dB/div: 10 dB Marker Function: Noise dBm/Hz Limit test: On with limit line programmed with the mask’s peak limit Start frequency: 25 kHz Stop frequency: 525 kHz Measure and record the PSD over the third segment of the mask, which covers the ADSL operating band on up to 525 kHz. For extended rate ADSL modems, repeat steps 1-4 for each supported EU mask. Note that the sample PSD plot shown in Figure 9.32-5 is for a standard ADSL modem subject to the mask limitations of TIA 968-A Clause 5.3.2.1.2. 1.54.15.4 9.32.5.4 Procedure for Segment 4, PSD with 10 kHz RBW 1. Condition the EUT to transmit continuously as described in 9.30.2. 2. Connect the EUT to the test circuit of Figure 9.32-6. 3. Set the spectrum analyzer as follows: Page 269 Telecommunications Industry Association TR41.9.1-10-05-002L Resolution bandwidth: 10 kHz Video bandwidth: 300 Hz Attenuation or range: Set for minimum without overload Reference level: (-70) dBm dB/div: 10 dB Marker Function: Noise dBm/Hz Limit test: On with limit line programmed with the mask’s peak Start frequency: 525 kHz Stop frequency: 30 MHz for TIA-968-B, 5.3.2.1.2 Stop frequency: 12 MHz for TIA-968-B, 5.3.3.1.1 Measure and record the PSD over the fourth segment of the mask, which covers the high frequencies above the ADSL operating band. For extended rate ADSL modems, repeat steps 1-4 for each supported EU mask. Note that the sample PSD plot shown in Figure 9.32-7 is for a standard ADSL modem subject to the mask limitations of TIA 968-B Clause 5.3.2.1.2. Note: The 10 dB pad may be omitted if the high-pass filter can withstand high input levels without introducing distortion products. Adjust the PSD readings to take into account losses introduced by the balun, pad and filter. 1.54.15.5 9.32.5.5 Procedure for Segment 4, PSD in a 1 MHz sliding window TIA-968B, 5.3.2.1.2, 5.3.3.1.1 1. Condition the EUT to transmit continuously as described in 9.30.2. 2. Connect the EUT to the test circuit of Figure 9.32-6. 3. Set the spectrum analyzer as follows: Resolution bandwidth: 10 kHz Video bandwidth: 300 Hz Attenuation or range: Set for minimum without overload Reference level: (-70) dBm dB/div: 10 dB Marker Function: Noise dBm/Hz Limit test: On (with limit line programmed with the mask limit for PSD in a 1 MHz sliding window). Start frequency: 1.221 MHz for TIA-968-B-3, 5.3.2.1.2 Page 270 Telecommunications Industry Association TR41.9.1-10-05-002L Stop frequency: 30 MHz for TIA-968-B-3, 5.3.2.1.2 Start frequency: 1.411 MHz for TIA-968-B-3, 5.3.3.1.1 Stop frequency: 12 MHz for TIA-968-B-3, 5.3.3.1.1 4. Measure and record the PSD over the prescribed frequencies above the ADSL operating band. 1. For measurements relative to TIA-968-B Clause 5.3.2.1.2, if the EUT’s PSD exceeds the corresponding PSD limit that defines the total power in a 1 MHz sliding window ,at any point above 1221 kHz, make measurements to calculate the total power in a 1 MHz sliding window. This concept was discussed in 9.31.6. Verify the peak limit of -90 dBm/Hz, above 1221 kHz, is never be exceeded by any individual spectral component. However, noise may exceed the dashed line limit provided that the power integrated over a 1 MHz bandwidth is less than -50 dBm. As an example, the dashed line in ANSI T1.413-1998 Figure 32 reaches a noise floor of -110 dBm/Hz, which over a 1 MHz band is equivalent to -50 dBm. 2. For measurements relative to TIA-968-B Clause 5.3.5.2.2, if the EUT’s PSD exceeds the mask limits at any frequency above 1411 kHz using a 10 kHz bandwidth, then average the PSD over a 1 MHz sliding window. Averaging 100 consecutive 10 kHz samples constrains the measurement to the proper frequency bands. For example, if a 1 MHz measurement bandwidth were used at a measurement frequency of 1411 kHz, the spectrum analyzer may not have sufficient dynamic range to measure below the specification limit. The measurement would include the contribution of frequencies considerably below the center frequency. (3) A faster measurement may be obtained using a time domain measurement device. 1.54.16 9.32.6 Alternative Methods A balun transformer may be used instead of the differential amplifier in subclause 9.32.5.1 as long as its frequency response and return loss are acceptable. Also, more than one type of balun may be used to cover the entire frequency range of interest. 1.54.17 9.32.7 Suggested Test Data 1. Plots of the PSD for each segment with the limit line shown on each graph 2. Line Data Rate and Baud Rate if applicable. 3. Total power or PSD in a 1 MHz sliding window as required. Page 271 Telecommunications Industry Association 1.54.18 TR41.9.1-10-05-002L 9.32.8 Comments Take care to ensure that measurement errors are kept to a minimum. Sources of error may include the following: Impedance deviations from the ideal 100 ohm termination Differential amplifier loss or gain Balun loss Attenuator pad loss over the ideal loss High-pass or low-pass filters’ frequency response Limited dynamic range of the differential amplifier Limited amplitude accuracy of the spectrum analyzer PSD measurement errors caused by excessively fast sweep times or not averaging enough samples when making a swept average measurement Figure 9.32-1. PSD Connection Diagram For Segments 1 & 2 Figure 9.32-2. Sample PSD Plot For Segment 1 Figure 9.32-3. Sample PSD Plot For Segment 2 Figure 9.32-4. PSD Connection Diagram For Segment 3 Figure 9.32-5. Sample PSD Plot For Segment 3 Figure 9.32-6. PSD Connection Diagram For Segment 4 Page 272 Telecommunications Industry Association TR41.9.1-10-05-002L Figure 9.32-7. Sample PSD Plot For Segment 4 9.33 Longitudinal Output Voltage, ADSL Terminal Equipment TIA-968-B, 5.3.2.3 1.54.19 9.33.1 Background Longitudinal output voltage (LOV) limits complement PSD limits by restricting the amplitude of common mode signals much like the PSD limits restrict the amplitude of the equipment’s differential mode signals. LOV limits are necessary as common mode signals tend to couple more readily than differential mode signals in multi-line, twisted pair cable plant. In other words, LOV limits are necessary to limit crosstalk. LOV limits have been crafted to allow higher levels around the equipment’s operating band. This is necessary as a common mode image of the desired differential mode signal results through imbalance in the line interface, cabling and the measurement circuitry. A tighter limit applies above the equipment’s operating band where the LOV source is usually not associated with any signal intended to be applied to the line. ADSL modems are required to meet certain LOV limits for voiceband terminal equipment. These measurements should be made using the procedure set out in subclasses 9.15 and 9.17. 1.54.20 9.33.2 Purpose To verify that the longitudinal output voltage is below the limit. 1.54.21 9.33.3 Equipment (1) Spectrum analyzer SEL#34. (2) LOV Test fixture shown in Figure 9.33-1. Note: Refer to subclause 5.5 for equipment details. 1.54.22 9.33.4 Equipment States Subject to Test Transmitting continuously as described in 9.30.2.. 1.54.23 9.33.5 Procedure Page 273 Telecommunications Industry Association TR41.9.1-10-05-002L 5. Condition the EUT to transmit continuously e as described in subclause 9.30.2. 6. Connect the EUT to the test circuit of Figure 9.33-1. 7. Set the spectrum analyzer as follows: Resolution bandwidth: 3 kHz Video bandwidth: 300 Hz Attenuation or range: Set for minimum without overload Reference level: (-30) dBV dB/div: 10 dB Start frequency: 10 kHz Stop frequency: 4fb Hz (as defined in TIA-968-B) Marker Function: Voltage dBV Limit test: On with limit line programmed with the LOV limit 5. Measure and record the LOV averaging the readings over several sweeps. Note: A resolution bandwidth (RBW) of 3 kHz is typically used as most spectrum analyzers support this RBW. 1.54.24 9.33.6 Alternative Methods None 1.54.25 9.33.7 Suggested Test Data (1) Plot of the LOV with the limit line shown (2) Line Data Rate and Baud Rate if applicable. 1.54.26 9.33.8 Comments Take care in the construction of the LOV test fixture. Test leads from the fixture to the EUT should be kept as short as possible to minimize RF ingress. The ground connection to the fixture Page 274 Telecommunications Industry Association TR41.9.1-10-05-002L should be of a low inductance, kept short, and connected directly to the chassis ground of the EUT. For EUT’s without an earth ground, a ground plane should be used as discussed in subclause 9.15.8. Figure 9.33-1. LOV Test Fixture & Connection Diagram Figure 9.33-2. Sample LOV Plot 9.34 Voiceband Signal Power - Non-approved external signal sources TIA-968-B, 5.1.4 1.54.27 Background Approved terminal equipment or approved protective circuitry may have ports through which external signal sources from non-approved equipment may be connected to the network. External signal sources include music-on-hold sources, recorded announcements, public address systems, studio radio/television patches, and so forth. Obviously, such sources have very high play-back levels and could be under the control of the users. To limit the signal level these sources could apply to the network, connect them through equipment that ensures appropriate limiting of the signals. Rationale for the specific limitations is discussed in subclause 9.1.1. Page 275 Telecommunications Industry Association 1.54.28 TR41.9.1-10-05-002L Purpose To verify compliance of the signal levels that are applied to the telephone network through approved terminal equipment or approved protective circuitry from non-approved external sources, other than data sources. 1.54.29 Equipment 1. Applicable loop simulator SEL#4 2. Frequency generator SEL#27. 3. True rms AC voltmeter SEL#40 (qty 2). Note: Refer to subclause 5.5 for equipment details. 1.54.30 Equipment States Subject to Test Test any off-hook state that transmits signals from non-approved equipment to the PSTN. 1.54.31 Procedure 1. Connect the EUT to the test circuit of Figure 9.36-1. 2. Place the EUT in the off-hook state with a mid-range loop current (any current in the range between 40 mA and 70 mA is acceptable). 3. Set the frequency generator to a frequency of 1000 Hz and an input level of 50 dBV. Measure the output level of the EUT. 4. Increase the level of the frequency generator in 1 dB steps and observe the signal level. (See comment (2)). 5. Determine the category of signal power limiting of the EUT and its input overload level value (see comment (3)). 6. Measure the output signal power level of the EUT when the level applied to the EUT is the overload value determined in step (5). Page 276 Telecommunications Industry Association TR41.9.1-10-05-002L 7. Monitor the signal power at the network interface on the voltmeter while varying the loop current. 8. Measure and record the maximum signal power level and the corresponding loop current. 9. Increase the level of the test signal source to 10 dB above the level in step (6) (see comment (4)). 10. Record the maximum voltage level at the network interface and verify that limiting of the signal power level occurs (see comment (5)). 11. Repeat step (6) through step (10) for other frequencies in the 200 Hz to 4000 Hz range. As a minimum, repeat the steps for 200, 500, 2000, and 4000 Hz. 1.54.32 Alternative Methods None suggested. 1.54.33 Suggested Test Data 1. Input and output signal power levels. 2. Test frequencies. 3. Loop conditions of maximum signal power. 1.54.34 Comments 1. All references to dBm are with respect to 600 ohms. 2. An EUT that uses a device (e.g. a thermistor) at the input to limit the signal power may result in a voltmeter not providing a true indication of the input level increase. This may be ascertained from a study of the schematic diagram. In such cases, or when in doubt, the input level should be determined with the EUT disconnected from the voltmeter. 3. There are essentially two categories of signal power limiting circuits: 1. Automatic Gain Control - An EUT with this type of signal power limiting has virtually no output signal for input levels below a certain value. At some input signal power level, the output level of the EUT will become significant (usually the expected output level for Page 277 Telecommunications Industry Association TR41.9.1-10-05-002L service application). The input level at which this occurs is defined as the "capture level." The "overload point" of the EUT is the value of the input signal that is 15 dB greater than the capture level. 2. Peak Limiting - An EUT with this type of limiting has virtually a constant throughtransmission gain over a range of input levels. As the input level is increased to values beyond this range, the gain of the EUT begins to decrease. The "overload point" of the EUT is defined as the input level at which the EUT's through gain decreases by 0.4 dB from its nominal constant gain. 4. It is not necessary to test the EUT for compliance with input levels greater than (+37) dBV. 5. The peak-to-average ratio of voiceband signals impacts the 3-second-average power. Other signals such as voice and music have peak-to-average signal power characteristics that vary over a large range; typically, they are greater than 13 dB. Such signals therefore have 3-second-average power that is at least 13 dB below their peak power. Hence, a peak limiting circuit that sets signal power limits to correspond to the 3-second-average power specified in TIA-968-B, subclause 5.1.2, is quite restrictive. It is quite restrictive for two reasons. First, the input/output characteristic was determined using a sinusoidal input, whose peak-to-average ratio is significantly smaller than typical signals. Furthermore, the average power of any signal applied to the network would have to be several dB below the limiting level to avoid distortion. Allowance for a reasonable peak-to-average ratio in setting the peak limiting protective circuit's maximum output level is reasonable and not likely to cause harm to the network. A reasonable value to use for the peak-to-average ratio is 13 dB. Consequently, a protection circuit which is categorized as a peak limiting device can have a maximum output level limited to a value 13 dB greater than that specified in TIA-968-B subclause 5.1.2. A protection circuit which is categorized as an AGC device has its output level limited to the level specified in TIA-968-B subclause 5.1.2. Page 278 Telecommunications Industry Association Page 279 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1. Refer to the figures of clause 1 of TIA-968-B. 2. Connect the voltmeter (VM2) across R1 of the loop simulator. 3. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to TIA-968-B figures 1.1 to 1.12. Figure 9.36-1. Voiceband Signal Power - Non-approved external signal sources Page 280 Telecommunications Industry Association Page 281 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L TRANSVERSE BALANCE LIMITATIONS TIA-968-B, 4.6 1.55 Transverse Balance, Analog TIA-968-B, 5.1.10 1.55.1 Background Crosstalk constitutes a "… degradation of service to persons other than the user of the subject terminal equipment, his calling or called party" (47 CFR, 68.3 - Definition of harm). Therefore crosstalk is minimized so that it cannot be detected by ordinary terminal equipment or equipment in the telephone network. Telecommunications terminals can be the cause of crosstalk into other circuits by converting differential mode (metallic) signals to common mode (longitudinal) signals and transmitting them toward the network. The interference can manifest itself as crosstalk in adjacent wire pairs in the same cable sheath. Such interference can be minimized by adequately controlling the symmetry of the terminal's impedances from each side of the line to ground. Transverse balance is a measure of the degree of that symmetry. It is a comparison of the voltage level of a metallic signal which is generated, to the voltage level of any resulting transverse signal; i.e., the ratio of metallic voltage, VM to transverse voltage, VL. The result is expressed in dB as follows: Thus, the greater the VM to VL ratio, the better the transverse balance of the terminal and the less likely it is to create interference. Transverse Balance tests are applicable to the on-hook and off-hook states of one-port 2-wire analog terminal equipment including central office implemented telephones. The Tip Ground state of a Central office implemented telephone should not be subjected to this test because the momentary (200 to 1200 ms) unbalanced condition during the Tip Ground state is not considered a network harm by network providers that use such payphones. 1.55.2 Purpose To determine the transverse balance of the EUT in its various operating modes. Page 282 Telecommunications Industry Association TR41.9.1-10-05-002L 1.55.3 Equipment 1. Applicable loop simulator SEL#4 (see comment 6). 2. Frequency generator SEL#27. 3. Frequency selective voltmeter SEL#28 or spectrum analyzer SEL#34. 4. Transverse balance bridge SEL#30. Note: Refer to subclause 5.5 for equipment details. 1.55.4 Equipment States Subject To Test 1. Power on: 1. On-hook (idle), when applicable. 2. Off-hook (quiet state). 2. Power off: 1. On-hook (idle), when applicable. 2. Off-hook (quiet state), if feasible with power off. 3. Power fail (if different than power off): 1. On-hook (idle), when applicable. 2. Off-hook (quiet state), if feasible with power fail. Note: Terminal equipment may require special attention to ensure it is properly configured for this test. For example, if the equipment would normally be connected to ac-power ground, cold-water-pipe ground, or if it has a metallic or partially metallic exposed surface, then these points should be connected to the test ground plane. Similarly, if the EUT provides connections to other equipment through which ground may be introduced to the equipment, then these points should be connected to the test ground plane. Equipment that does not contain any of these potential connections to ground should be placed on a conductive plate that is connected to the test ground plane (see comment 2); this applies to both non powered and ac-powered equipment. Page 283 Telecommunications Industry Association TR41.9.1-10-05-002L 1.55.5 Procedure 1. Connect a 600 ohm resistor to the test circuit of Figure 10.1-1. 2. Set the frequency generator to 200 Hz. 3. Adjust the frequency generator to an output level of 0.775 Vrms (0dBm) as measured by the frequency selective voltmeter or spectrum analyzer set at 10 Hz bandwidth and balanced input, across the 600 ohm calibration resistor (see comment 8). 4. Connect the frequency selective voltmeter or spectrum analyzer across the 500 ohm transverse termination resistor. 5. Adjust variable capacitors C3 and C4 until the minimum VL level across the 500 ohm resistor is obtained. This represents the highest degree to which the bridge can be balanced at the frequency being measured referenced to the level set in step (3). Verify that the result of this balance calibration is at least 20 dB greater than the balance requirement for the EUT at that frequency specified in TIA-968-B clause 5.1.10. 6. Substitute the EUT for the 600 ohm resistor. For multiport EUT, see comment 1. 7. Vary the loop current, for off-hook conditions, over the available range of loop currents, observing the worst-case balance (maximum voltage across the 500 ohm resistor). 8. Return the loop simulator to the condition resulting in the worst-case balance noted in step (7). 9. Measure the voltage across the tip and ring of the EUT; this is the metallic reference voltage (VM). 10. Measure the voltage across the 500 ohm resistor; this is the longitudinal voltage (VL). 11. Calculate the balance using the following formula: Note: If the readings are, for example, taken in dBV, then the equation may be simplified to: Page 284 Telecommunications Industry Association TR41.9.1-10-05-002L 12. Reverse the tip and ring connections of the EUT and repeat step (9) to step (11). The lesser of the two results is the transverse balance of the EUT at 200 Hz. 13. Repeat step (3) through step (12) for at least each of the following frequencies: 500, 1000, 2000, 3000, and 4000 Hz, with the resolution bandwidth set for 10 Hz for the 500 Hz measurement and 30 Hz for all other frequencies (See Comment 3 and Comment 8). 14. Repeat step (2) through step (13) for all applicable equipment states. 1.55.6 Alternative Methods See Appendix C. 1.55.7 Suggested Test Data 1. Frequencies tested. 2. Balance measured of the frequencies tested. 3. EUT and loop simulator condition for each measurement. 1.55.8 Comments 1. For multiport EUTs, input leads of ports not under test should be properly terminated by connecting the terminating network shown in TIA-968-B, Figure 4.9 to the ports of the EUT not under test. Prior to connection, this terminating network should be adjusted for its maximum balance by attaching it to the balance test set and adjusting its potentiometer. Include the DC portion of the loop simulator during the calibration process. 2. EUT that is not normally grounded should be set in its normal position directly on a conductive plate. It is recommended that the overall area of the conductive plate be at least 50% greater than that of the base of the EUT. This represents the closest proximity to ground that is likely to be encountered by the EUT. 3. Interference from power frequency harmonics can be minimized by using test frequencies midway between multiples of 60 Hz. Page 285 Telecommunications Industry Association TR41.9.1-10-05-002L 4. In some cases, the EUT may apply internally generated signals to the test set. Such signals should not be construed as part of the transverse balance test. 5. If a frequency selective voltmeter or spectrum analyzer are not available, transverse balance measurements may be made if: 1. The environment is relatively free from electromagnetic interference in the voiceband; and 2. The EUT generates very low in-band noise. 3. A bandpass filter with sufficient attenuation above and below the cutoff frequencies and a high impedance voltmeter, each with a balanced input, may be used. 6. To achieve an acceptable degree of calibration balance, the use of batteries in the loop simulator circuit is recommended. 7. A DC current meter may be included as part of the loop simulator circuit in order to monitor loop conditions. 8. For low frequencies, the narrower bandwidth (i.e. 10 Hz) is used in order to avoid interference from power frequency harmonics. For the higher frequencies, the wider bandwidth is used in order to enhance the measurement stability. Page 286 Telecommunications Industry Association Page 287 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L T1 600 ohm: 600 ohm split audio transformer C1, C2 8 µF, 400 V DC, matched to within 0.1% C3, C4 100 to 500 pF adjustable trimmer capacitors Osc Audio oscillator with source resistance R1 less than or equal to 600 ohms R1 Selected such that ZOSC + R1 = 600 ohms RL 500 ohms 1. VM should not be measured at the same time as VL. 2. The test circuit should be balanced to 20 dB greater than the equipment standard for all frequencies specified (using trimmer capacitors C3 and C4), with a 600 ohm resistor substituted for the equipment under test. Exposed conductive surfaces on the exterior of the equipment under test should be connected to the ground plane for this test. When the Terminal Equipment makes provision for an external connection to ground, the Terminal Equipment should be connected to ground. When the Terminal Equipment makes no provision for an external ground, the Terminal Equipment should be placed on a ground plane that is connected to ground and has overall dimensions at least 50% greater than the corresponding dimensions of the Terminal Equipment. The Terminal Equipment should be centrally located on the ground plane without any additional connection to ground. 3. Refer to the figures of clause 1 of TIA-968-B. Figure 10.1-1 Transverse Balance, Analog 2. Transverse Balance, Digital TIA-968-B, 5.2.2.2, 5.2.3.2, 5.2.4.7, 5.3.2.2 1. Background See subclause 10.1.1. 2. Purpose To determine transverse balance of digital EUT. 3. Equipment Page 288 Telecommunications Industry Association TR41.9.1-10-05-002L 1. Spectrum analyzer SEL#34 2. Tracking generator SEL#39. Note: Refer to subclause 5.5 for equipment details. 4. Equipment States Subject To Test Active state with appropriate grounding applied. Note: Terminal equipment may require special attention to ensure it is properly configured for this test. For example, if the equipment would normally be connected to ac-power ground, cold-water-pipe ground, or if it has a metallic or partially metallic exposed surface, then these points should be connected to the test ground plane. Similarly, if the EUT provides connections to other equipment through which ground may be introduced to the equipment, then these points should be connected to the test ground plane. Equipment that does not contain any of these potential connections to ground should be placed on a conductive plate that is connected to the test ground plane (see comment 1); this applies to both non powered and ac-powered equipment. 5. Procedure 1. Connect the EUT to the test circuit of Figure 10.2-1 with the appropriate calibration test resistor (135 ohms or 100 ohms) in place. 2. Set the spectrum analyzer and tracking generator to the appropriate frequency ranges: 1. For 2.4 kilobit per second (kb/s) subrate EUT - 200 Hz to 2.4 kHz 2. For 3.2 kilobit per second (kb/s) subrate EUT - 200 Hz to 3.2 kHz 3. For 4.8 kilobit per second (kb/s) subrate EUT - 200 Hz to 4.8 kHz 4. For 6.4 kilobit per second (kb/s) subrate EUT - 200 Hz to 6.4 kHz 5. For 9.6 kb/s kilobit per second (kb/s) subrate EUT - 200 Hz to 9.6 kHz 6. For 12.8 kb/s kilobit per second (kb/s) subrate EUT - 200 Hz to 12.8 kHz 7. For 19.2 kb/s kilobit per second (kb/s) subrate EUT - 200 Hz to 19.2 kHz 8. For 25.6 kb/s kilobit per second (kb/s) subrate EUT - 200 Hz to 25.6 kHz Page 289 Telecommunications Industry Association TR41.9.1-10-05-002L 9. For 38.4 kb/s kilobit per second (kb/s) subrate EUT - 200 Hz to 38.4 kHz 10. For 51.2 kb/s kilobit per second (kb/s) subrate EUT - 200 Hz to 51.2 kHz 11. For 56.0 kb/s kilobit per second (kb/s) subrate EUT - 200 Hz to 56.0 kHz 12. For 72.0 kb/s kilobit per second (kb/s) subrate EUT - 200 Hz to 72.0 kHz 13. For BRA EUT - 200 Hz to 192 kHz 14. For DS1 (1.544 Mb/s) EUT - 12 kHz to 1.544 MHz 15. For ADSL EUT – 13.6 kHz to 1.625 MHz (see comment 6) 16. For ADSL2+ EUT - 13.6 kHz to 2.425 MHz (see comment 6) 3. Adjust the tracking generator voltage to measure a VM of 0.367 Vrms across the calibration test resistor of 135 ohms or 0.316 Vrms across the calibration test resistor of 100 ohms as appropriate. 4. Connect the spectrum analyzer across the RL resistor (90 or 500 ohms as per TIA-968-B, Table 4.12). 5. Adjust capacitor C1 until a minimum voltage across the RL resistor is obtained. This represents the highest degree to which the bridge can be balanced. The result of this balance calibration should be at least 20 dB better than the requirement for the applicable frequency band. If this degree of balance cannot be attained, further attention should be given to component selection for the test circuit and its construction. 6. Reverse the polarity of the tip-and-ring pair under test. If the transverse voltage (VL) changes by less than 1 dB, the calibration is acceptable. If the transverse voltage changes by more than 1 dB, it indicates that the bridge needs further adjustment to accurately measure the balance of the EUT. Repeat the calibration process until the measurements differ by less than 1 dB while maintaining the balance noted in step (5) above. 7. Replace the calibration resistor with one tip-and-ring pair of the EUT (see comment 4). 8. Measure the voltage across the tip and ring of the EUT; this is the metallic reference voltage (VM). 9. Measure the voltage across the RL resistor; this is the longitudinal voltage (VL). 10. Calculate the balance using the following formula: Page 290 Telecommunications Industry Association TR41.9.1-10-05-002L Note: If the readings are, for example, taken in dBV, then the equation may be simplified to: 11. Reverse the tip and ring connections of the EUT and repeat step (8) through step (10). The lesser of the two results is the transverse balance of this pair of the EUT. (12) If applicable, connect the other tip and ring pair of the EUT to the balance test set (see comment 4). (13) Repeat step (8) through step (11) for this pair. 6. Alternative Methods See Appendix C. 7. Suggested Test Data 1. EUT tip and ring pair tested. 2. Frequencies tested. 3. Balance measured for the pair. 4. Calibration balance measured. 8. Comments 1. EUT that is not normally grounded should be set in its normal position directly on a conductive plate. It is recommended that the overall area of the conductive plate be at least 50% greater than that of the base of the EUT. This represents the closest proximity to ground that is likely to be encountered by the EUT. 2. Interference from power frequency harmonics can be minimized by using test frequencies midway between multiples of 60 Hz. Page 291 Telecommunications Industry Association TR41.9.1-10-05-002L 3. In some cases, EUT may apply internally generated signals to the test set. Such signals should not be construed as part of the transverse balance test. 4. Some digital equipment referenced in this subclause has a transmit pair and a receive pair. Balance measurements should be performed on both pairs. 5. Test leads between the test fixture and the EUT will affect the calibration and EUT balance measurements. Ensure that such cables are in place when making the calibration balance adjustments. 6. Alternatively, a narrower frequency range may be used for the family of ADSL EUT that is defined by the points at which the measured power spectral density is 20 dB down from the maximum level associated with both the maximum rate upstream and downstream signals. Page 292 Telecommunications Industry Association Page 293 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 100/135 ohms:100/135 ohm wide-band transformer T1 (100 for 1.544 Mbps or ADSL devices and 135 for sub-rate or BRA devices.) 20pF Optimally a dual-stator air-variable RF capacitor that maintains a constant capacitance Differential between stators while providing a variable capacitance from either stator to ground. 3 pF Composition RF capacitor RCAL 100/135 ohms (See Note 2) RL 90/500 ohms: A non-inductive precision resistor (chosen according to Table 4.12). 1. The 3 pF capacitor may be placed on either line of the test set, as required, to obtain proper balancing of the bridge. 2. Use an RCAL value of 100 ohms for 1.544 Mbps or ADSL devices and 135 ohms for sub-rate or BRA devices. 3. The effective output impedance of the tracking generator should match the appropriate test impedance. See Note 2. The spectrum analyzer's input should be differentially balanced to measure VM. 4. The impedance of the Tracking Generator should be chosen to match the Metallic Termination (RM) according to TIA-968-B, Table 4.12. 5. The transformer should be a wide band transformer with a 1:1 impedance ratio. Figure 10.2-1 Transverse Balance, Digital Page 294 Telecommunications Industry Association TR41.9.1-10-05-002L ON HOOK IMPEDANCE LIMITATIONS TIA-968-B, 4.7 1.56 DC Resistance TIA-968-B, 5.1.11.2.1, 5.1.11.2.2 1.56.1 Background This requirement is necessary to avoid interference with telephone company maintenance procedures. Telephone companies determine whether there is a line insulation fault in their wire facilities by applying DC voltages to the individual wire pairs. A fault condition is determined by the amount of current flow when DC voltages up to 200 V of either polarity are applied to a wire pair. For DC voltages up to 100 V, the telephone company expects the total DC resistance of all terminal equipment bridged across a wire pair to be greater than 5 megohms. (Any less resistance would interfere with the line insulation tests and the ability to isolate a line problem from a terminal equipment problem.) For DC voltages between 100 V and 200 V, the total DC resistance of all connected terminal equipment is specified to be greater than 30 kilohms. 1.56.2 Purpose To measure the DC resistance of the EUT during its idle, or on-hook state. 1.56.3 Equipment 1. DC current meter SEL#19 or 20. 2. DC power supply SEL#21. 3. DC voltmeter SEL#22. Note: Refer to subclause 5.5 for equipment details. 1.56.4 Equipment States Subject To Test The EUT should be in its idle or on-hook state. It may be necessary to test in both powered and non-powered states if the EUT requires external power. 1.56.5 Procedure 1. Connect the EUT to the test circuit of Figure 11.1-1. Page 295 Telecommunications Industry Association TR41.9.1-10-05-002L 2. Set the voltage to 1 V DC and allow the circuit to stabilise. 3. Slowly increase the voltage to 100 volts and observe the current as the voltage is increased. 4. If the current is < 0.2 microamps over this range, measure and record the current at 1 volt. Use this value to calculate the minimum DC resistance for the 1 to 100 volts range. 5. If the current increases suddenly at any point, record the voltage and current at these points. Calculate the DC resistance at these points. 6. In addition to any points recorded in step (5), measure and record the current at voltages of 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100 volts. Use these values to calculate the DC resistance at these voltages. 7. Slowly increase the voltage from 100 to 200 volts and observe the current as the voltage is increased. 8. If the current is < 3.3 mA ( for measurements of current < 20 A, use meter #19 from the SEL) over this range, measure and record the current at 100 volts. Use this value to calculate the minimum DC resistance for the 100 to 200 volts range. 9. If the current increases suddenly at any point, record the voltage and current at these points. 10. In addition to any points recorded in step (7), measure and record the current at voltages of 100, 150, and 200 volts. 11. Reverse the polarity of the test circuit and repeat steps (2) through (10). 12. Connect the EUT to the test circuit of figure 11.1-2. 13. Repeat steps (2) through step (10) with connections made to the tip and ground leads of the EUT. 14. Repeat Steps (2) through (10) with connections made to the ring and ground leads of the EUT. 1.56.6 Alternative Methods Programmable DC resistance meters are available. Page 296 Telecommunications Industry Association TR41.9.1-10-05-002L 1.56.7 Suggested Test Data 1. Statement that voltage was swept from 1 to 200 volts. 2. DC test voltages. 3. DC current readings. 4. DC resistances (calculated). 1.56.8 Comments 1. The internal resistances of all measuring equipment is to be taken into account. 2. Care should be exercised to prevent electromagnetic interference from affecting the DC current measurements. Figure 11.1-1. DC Resistance, T-R Note: The 1 kilohm resistor is provided as a current limiter. Figure 11.1-2. DC Resistance, T-GND & R-GND Page 297 Telecommunications Industry Association TR41.9.1-10-05-002L 1.57 DC Current During Ringing, Loop Start and Ground Start TIA-968-B, 5.1.11.2.3, 5.1.12.2.3 1. 5.1.11.2.3 for loop start 2. 5.1.12.2.3 for ground start 1.57.1 Background The limits placed on the DC current and AC impedance of terminal equipment during ringing are to ensure that it does not cause the ring trip equipment at the CO to disconnect the ringing generator prematurely (pre-trip). Ring trip equipment in COs respond to either DC current or the combination of AC and DC current. When pre-trip occurs, the calling customer does not receive audible ringback and perceives that the call did not complete. Thus, the calling customer will make repeated attempts, needlessly tie up the telephone network facilities, and possibly initiate unnecessary maintenance efforts by the telephone company. 1.57.2 Purpose To measure the DC current that results from the nonlinear characteristics of the EUT during ringing. 1.57.3 Equipment 1. AC Volt Meter SEL#3. 2. DC current meter SEL#19. 3. DC power supply SEL#21. 4. Frequency generator SEL#27. 5. Ringing amplifier SEL#33. Note: Refer to subclause 5.5 for equipment details. 1.57.4 Equipment States Subject To Test Page 298 Telecommunications Industry Association TR41.9.1-10-05-002L The EUT should be in its idle or on-hook state. If the EUT is an auto answer device, some means to disable this feature is necessary. It may be necessary to test in both powered and non-powered states if the EUT requires external power. 1.57.5 Procedure 1. Connect the EUT to the test circuit of Figure 11.2-1. 2. Set the test equipment to supply the lowest frequency and voltage listed in Table 4.13 of subclause 4.7 for the ringing type being tested. 3. Record the DC current. 4. Increase the ringing voltage to the maximum for the chosen ringer type from Table 4.13 of subclause 4.7. 5. Record the DC current. 6. Repeat step (3) through step (5) for the other recommended frequencies (See comment (1)). 7. Reverse the connections of the EUT to the test circuit and repeat step (2) through step (6). 1.57.6 Alternative Methods None suggested. 1.57.7 Suggested Test Data The DC current at each of the AC voltage levels and frequencies. 1.57.8 Comments 1. For “A” type ringers, measure at 20 and 30 Hz. For "B" ringers, measure at 15.3, 20, 35, 50, and 68 Hz. 2. Take into account the internal characteristics (impedances) of all monitoring equipment. Page 299 Telecommunications Industry Association TR41.9.1-10-05-002L 3. If the EUT derives operating power or power assist from the incoming ringing signal, the EUT may be damaged by the continuously applied ringing as described in this subclause. In such cases, special cadenced ringing tests maybe necessary to obtain data. The ringing cadence is typically a repetitive cycle of two seconds on and four seconds off. Figure 11.2-1. DC Current During Ringing Page 300 Telecommunications Industry Association TR41.9.1-10-05-002L 1.58 AC Impedance During Ringing, Loop Start and Ground Start (Metallic and Longitudinal) TIA-968-B, 5.1.11.2.4, 5.1.11.2.5, 5.1.12.2.2 1. 5.1.11.2.4 and 5.1.11.2.5 for loop start 2. 5.1.12.2.2 for ground start 1.58.1 Background The limits placed on the DC current and AC impedance of terminal equipment during ringing are to ensure that it does not cause the ring trip equipment at the CO to disconnect the ringing generator prematurely (pre-trip). Ring trip equipment in COs respond to either DC current or the combination of AC and DC current. When pre-trip occurs, the calling customer does not receive audible ringback and perceives that the call did not complete. Thus, the calling customer will make repeated attempts, needlessly tie up the telephone network facilities, and possibly initiate needless maintenance efforts by the telephone company. 1.58.2 Purpose To measure the AC impedance of the EUT during ringing. 1.58.3 Equipment 1. AC current meter SEL#1. 2. AC Volt Meter SEL#3. 3. DC power supply SEL#21. 4. Frequency generator SEL#27. 5. Ringing amplifier SEL#33. Note: Refer to subclause 5.5 for equipment details. Page 301 Telecommunications Industry Association TR41.9.1-10-05-002L 1.58.4 Equipment States Subject To Test The EUT should be in its idle or on-hook state. If the EUT is an auto answer device, some means to disable this feature is necessary. It may be necessary to test in both powered and non-powered states if the EUT requires external power. 1.58.5 Procedure 1. Connect the EUT to the test circuit of Figure 11.3-1. 2. Set the frequency generator to the lowest frequency and voltage listed in Table 4.13 of subclause 4.7 for the ringing type being tested. 3. Record the current. 4. Calculate the AC impedance of the EUT. 5. Increase the ringing voltage to the maximum for the chosen ringer type from Table 4.13 of subclause 4.7. 6. Record the current. 7. Calculate the AC impedance of the EUT. 8. Repeat step (2) through step (7) at the other frequencies (see comment (1)). 9. Reverse the connections of the EUT to the test circuit and repeat step (2) through step (8). 10. Connect the EUT to the test circuit of Figure 11.3-2. 11. Repeat step (2) through step (9). 1.58.6 Alternative Methods None suggested. 1.58.7 Suggested Test Data Page 302 Telecommunications Industry Association TR41.9.1-10-05-002L 1. The current at the various AC voltage levels and frequencies. 2. Calculated AC impedances. 1.58.8 Comments 1. For “A” type ringers, measure at 20 and 30 Hz. For "B" ringers, measure at 15.3, 20, 35, 50, and 68 Hz. 2. Take into account the internal characteristics (impedances) of all monitoring equipment. 3. If the EUT derives operating power or power assist from the incoming ring, the EUT may be damaged by the continuously applied ringing as described in this subclause. In such cases, special cadenced ringing tests maybe necessary to obtain data. The ringing cadence is typically a repetitive cycle of two seconds on and four seconds off. 4. When testing series connected devices, remove all terminations from the non-network side of the EUT as they could adversely affect the measurement. Page 303 Telecommunications Industry Association Page 304 TR41.9.1-10-05-002L Telecommunications Industry Association Figure 11.3-1. AC Impedance, T-R Page 305 TR41.9.1-10-05-002L Telecommunications Industry Association Page 306 TR41.9.1-10-05-002L Telecommunications Industry Association Figure 11.3-2. AC Impedance, T-GND & R-GND Page 307 TR41.9.1-10-05-002L Telecommunications Industry Association Page 308 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.59 REN Calculation TIA-968-B, 5.1.11.2.7, 5.1.11.2.8 1.59.1 Background The on-hook requirements for AC impedance are specified in terms of the combined effect of all terminal equipment connected to a particular network connection when a ringing signal is applied by the CO. The ringer equivalence number (REN) provides a method for allocating these requirements among terminal equipment devices attached to a network connection. The REN also provides the customer with a simple procedure for determining if the combined effect of all devices attached to the line is likely to cause network operational faults. The customer determines this effect by adding the REN of each device connected to the telephone line in question. The total REN should be less than 5.0. 1.59.2 Purpose To calculate the REN for the EUT. 1.59.3 Equipment None. 1.59.4 Equipment States Subject To Test Not applicable. 1.59.5 Procedure Refer to subclause 4.7.4 for computation of REN. Use data obtained in subclause 11.3. 1.59.6 Alternative Methods None suggested. 1.59.7 Suggested Test Data A tabulation of the calculations performed. Page 309 Telecommunications Industry Association TR41.9.1-10-05-002L 1.59.8 Comments The following is an example of how an REN (ac) of 0.7B is derived for "individual equipment intended for connection to loop start facilities": 1. AC data derived from subclause 11.3.5 is converted to REN numbers as described in subclause 4.7.4 for tests at 16 Hz and 68 Hz, and subclause 4.7, Table 4.13, ringing type B: 2. Assume at 150 V rms, 12.3 mA AC is measured at 68 Hz. Ringer Impedance = = 12.2 kohms Assume 12.2 kohms to be the lowest ringer impedance for all ringing conditions. 3. Ringing type B allows a ringer impedance of 1600 ohms minimum on a single line (refer to subclause 4.7), which is equivalent to 5 ringers each having a ringer load of 8000 ohms (5 X 1600 ohms). To calculate the ringer load (REN) for the EUT: REN = 4. Thus, REN (ac) = 0.7B (rounded to nearest tenth) telephone ringer load. In this case, seven such EUTs could be attached to a single loop start line. The "B" stipulates the ringer type. The total REN is recorded on the label of the device in accordance with the labelling requirement of the ACTA. Page 310 Telecommunications Industry Association Page 311 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.60 OPS Ring Trip, PBX with DID TIA-968-B, 5.1.15.7 1.60.1 Background The purpose of this test is to ensure that a PBX will apply ringing towards an OPS in order to complete a DID call. If the PBX's ringing generator trips prematurely, the calling party will believe the call failed to complete and will repeat the attempt. This failure to operate correctly results in unnecessary network maintenance procedures. In this test, the ringing generator is terminated by an impedance that simulates the wire pair impedance terminated by station set ringers with the stations in their on-hook condition. 1.60.2 Purpose To verify that the EUT will not trip ringing when the maximum number of telephone instruments as specified by the PBX manufacturer are connected to an OPS. 1.60.3 Equipment None. 1.60.4 Equipment States Subject To Test The PBX equipment is to be tested while it is ringing an off premise station. 1.60.5 Procedure 1. Calculate the values for R and C according to subclause 4.7.6. 2. Connect the EUT to the test circuit of Figure 11.5-1. 3. Cause the EUT to generate ringing toward the termination. 4. Verify that ringing has not tripped. 1.60.6 Alternative Methods None suggested. Page 312 Telecommunications Industry Association TR41.9.1-10-05-002L 1.60.7 Suggested Test Data Test data should include the number of equivalent ringers (N) specified for the interface under test, and confirmation that this termination did not trip ringing. 1.60.8 Comments None. Page 313 Telecommunications Industry Association Page 314 TR41.9.1-10-05-002L Telecommunications Industry Association Note: The value of R and C are calculated in accordance with subclause 4.7.6. Figure 11.5-1. OPS Ring Trip Page 315 TR41.9.1-10-05-002L Telecommunications Industry Association Page 316 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.61 Transitioning to the Off-Hook State and Make-busy TIA-968-B, 5.1.11.3, 5.1.12.3 1.61.1 Background This requirement prevents the intentional design of terminal equipment that will apply a termination across the network connection for the purpose of making that equipment and its network connection busy for incoming calls. The FCC does permit a station to go off-hook, applying a temporary busy on that circuit, for the purpose of programming an automatic dialer with the selected telephone numbers for future network dialing purposes. The FCC also allows the terminal equipment to go off-hook, applying a temporary busy on that circuit, for the purpose of detecting the presence of stutter dial tone. The definition of the make-busy leads is presented in subclause 1.3. 1.61.2 Purpose To verify that the EUT does not go off-hook except for the purpose of initiating or receiving a call, subject to the exceptions allowed in TIA-968-B, subclause 4.7.8.1 and 4.7.8.2. 1.61.3 Equipment None. 1.61.4 Equipment States Subject To Test Not applicable. 1.61.5 Procedure Evaluate the EUT to ensure that it does not go off-hook for purposes other than initiating a call, receiving a call, manual programming of memory dialing numbers or automatic stutter dial tone detection. 1.61.6 Alternate Methods None. Page 317 Telecommunications Industry Association TR41.9.1-10-05-002L 1.61.7 Suggested Test Data Engineering analysis of EUT. 1.61.8 Comments This subclause describes the usage of the make-busy feature. It does not have any specific tests that apply to the make-busy function. The MB and MB1 leads are considered telephone connections and should comply with the requirements of TIA-968-B, subclauses 4.3 and 4.4 when isolated from tip and ring. When the corresponding telephone line is of the loop start type, the tip and ring leads should comply with all of TIA-968-B when the MB and MB1 leads are bridged to the tip and ring connections. Page 318 Telecommunications Industry Association Page 319 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.62 Manual Programming of Repertory Numbers, TIA-968-B, 5.1.11.3.1, 5.1.12.3.1 1.62.1 Background This requirement is applicable to product capable of providing repertory (memory) or automatic dialing for network addressing. The user is allowed to place the product in the off-hook state for programming of repertory numbers or automatic dialing. 1.62.2 Purpose To verify that the equipment can program memory dialing in the off-hook state without providing actual network address signaling (e.g. DTMF or pulse dialing). 1.62.3 Equipment Oscilloscope SEL #23 Note: refer to subclause 5.5 for equipment details. 1.62.4 Equipment States Subject to Test Test any off-hook state. 1.62.5 Procedure 1. Examine the customer instructions for the EUT and determine if it provides the capability to program internal memory for repertory or automatic dialing. 2. Set the EUT to the appropriate dial method, and connect to the test circuit 11.7-1. 3. Place the EUT off-hook and perform the recommended programming sequence. 1.62.6 Alternative Methods None suggested Page 320 Telecommunications Industry Association TR41.9.1-10-05-002L 1.62.7 Suggested Test Data State if network address signals or pulses are generated on tip and ring during the off-hook programming sequence. 1.62.8 Comments This requirement is applicable to all EUT that provides memory or automatic dialing. 1. Select the appropriate loop simulator for the interface of the EUT. Refer to the figures of clause 1 of TIA968-B. 2. The oscilloscope should provide a balanced input. Figure 11.7-1. Manual Programming of Repertory Dialing Numbers Page 321 Telecommunications Industry Association Page 322 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.63 Automatic Stuttered Dial Tone Detection TIA-968-B, 5.1.11.3.2, 5.1.12.3.2 1.63.1 Background It is possible for some equipment to use automatic off-hook checks of the line to detect a stutter dial tone, which is used to provide an audible signal to the equipment user in support of certain network features. Unlimited or excessively long duration automatic off-hook checks for the purpose of stutter dial tone detection is a misuse of network facilities and is considered network harm. 1.63.2 Purpose To verify that the characteristics of the EUT automatic off-hook checks for stutter dial tone detection meet the requirements of TIA-968-B. 1.63.3 Equipment 1. Applicable loop simulator SEL#4. 2. Storage oscilloscope SEL#23. 3. Frequency generator SEL#27. 4. Ringing amplifier SEL#33. 1.63.4 Equipment States Subject To Test Test when the EUT makes a stutter dial tone check. 1.63.5 Procedure 1. Consult the EUT manual to determine if the equipment performs automatic stutter dial tone detection. Equipment that does not support this function is not subject to this test. Verify that equipment supporting this function passes the conditions of steps (2) through (6). 2. Connect the EUT to the test circuit of Figure 11.8-1. Page 323 Telecommunications Industry Association TR41.9.1-10-05-002L 3. Simulate the completion of a calling event by means of the host or ancillary telephone set. Monitor and record the number of stuttered dial tone checks that occur and when they occur. 4. Simulate an unanswered incoming calling event. Monitor and record the number of stuttered dial tone checks that occur and when they occur. If the device has a visual message indicator, set the EUT so that the indicator is lit. Simulate an unanswered incoming calling event. Monitor and record the number of stuttered dial tone checks that occur and when they occur. 5. Cause the EUT to perform a stuttered dial tone check as in step (3) above. When the device goes off-hook, apply dial tone within 3 seconds. Measure the amount of time from the initial application of the dial tone to when the device goes back on-hook. 6. Cause the EUT to perform a stuttered dial tone check as in step (3) above. When the device goes off hook, do not apply dial tone within the first 3 seconds. Monitor and record when the EUT goes back on hook. 1.63.6 Alternate Methods None. 1.63.7 Suggested Test Data 1. Number of stuttered dial tone checks after the completion of a calling event. 2. Time interval from the completion of a calling event to the completion of the stuttered dial tone check. 3. Number of stuttered dial tone checks after the completion of an unanswered incoming calling event. 4. Number of stuttered dial tone checks after the completion of an unanswered incoming calling event attempted while the visual message indicator is lit. 5. Duration of the stuttered dial tone check after dial tone application when dial tone is applied within three seconds. 6. Duration of the stuttered dial tone check with no dial tone applied within three seconds. 7. Provide an attestation that states that the design of the EUT complies with the requirement of subclause 4.7.8.2 a), f) and g) of TIA-968-B. Page 324 Telecommunications Industry Association TR41.9.1-10-05-002L 1.63.8 Comments 1. The suggested level for application of dial tone is -13 dBm. This corresponds with specified network levels. 2. Dial tone is specified in T1.401. 1. Select the appropriate loop simulator for the interface of the EUT. Refer to the figures of clause 1 of TIA968-B. 2. The oscilloscope should provide a balanced input. Figure 11.8-1. Manual Programming of Repertory Dialing Numbers Page 325 Telecommunications Industry Association Page 326 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L BILLING PROTECTION TIA-968-B, 4.4 1.64 Call Duration for Data Equipment, Protective Circuitry TIA-968-B, 4.4.1.1 1.64.1 Background This requirement applies to protective circuitry for data equipment that has access to the public switched network. The two-second delay before transmission of the data signal, after the offhook condition is presented to the telephone network in response to an incoming call, is to allow billing equipment to be connected and prepared for proper billing. The specified 55 dBm limit for transmission is considered to be equivalent to no transmission and applies in both the transmit and receive conditions. 1.64.2 Purpose To verify that no data is delivered to or received from the network for the first two seconds after answering an incoming call through a protective circuit. 1.64.3 Equipment 1. Applicable loop simulator SEL#4. 2. Bandpass filter SEL#12. 3. Digital sampling storage oscilloscope SEL#24. 4. Frequency generator SEL#27. 5. Ringing amplifier SEL#33. Note: Refer to subclause 5.5 for equipment details. Page 327 Telecommunications Industry Association TR41.9.1-10-05-002L 1.64.4 Equipment States Subject to Test Answering an incoming call (on-hook to off-hook transition). 1.64.5 Procedure 1. Connect the EUT to the test circuit of Figure 12.1 1. 2. Set the frequency generator for 1000 Hz and 0 dBm. 3. Set the oscilloscope to trigger on transition from the on hook to the off-hook state of the EUT. 4. Apply the ringing signal to the EUT. 5. Record the signal level that is transmitted to the network after the EUT goes off-hook. Check for compliance during the first 2 seconds after going off-hook. 6. Connect the EUT to the test circuit of Figure 12.1 2. 7. Set the frequency generator to 1000 Hz and -55 dBm. 8. Place the EUT in the off-hook state. Measure the signal power that would be delivered to the data equipment from the network through the EUT in response to a received signal power of -55 dBm. Return the EUT to its on hook state. 9. Increase the input signal 0 dBm. 10. Set the oscilloscope to trigger on transition from the on hook to the off-hook state of the EUT. 11. Apply the ringing signal to the EUT. 12. Measure the signal power that would be received by the data equipment from the Network through the EUT (see comment (3)). 1.64.6 Alternate Methods None suggested. Page 328 Telecommunications Industry Association TR41.9.1-10-05-002L 1.64.7 Suggested Test Data 1. Signal power in dBm for at least the first two seconds after transition to the off hook state in both directions of transmission. 2. Verification of data delay. 1.64.8 Comments 1. Actual data signals may be used in place of the signal generator. 2. Test frequencies other than 1000 Hz may be used. 3. The signal level measured in Step (12) should be no greater than the signal level in Step (8). 1. Select the appropriate loop simulator for the interface of the EUT. 2. Connect the bandpass filter across R1 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. Figure 12.1-1. Call Duration, PC, Transmit Page 329 Telecommunications Industry Association Page 330 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1. Select the appropriate loop simulator for the interface of the EUT. 2. Connect the bandpass filter across R1 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. Figure 12.1-2. Call Duration, PC, Receive Page 331 Telecommunications Industry Association TR41.9.1-10-05-002L 1.65 Call Duration for Data Applications, Terminal Equipment TIA-968-B, 4.4.1.2 1.65.1 Background This requirement applies to data equipment that accesses the public switched network. The twosecond delay before transmission of the data signal after the off-hook condition is presented to the telephone network in response to an incoming call is to allow billing equipment to be connected and prepared for proper billing. 1.65.2 Purpose To verify that the data equipment does not transmit or receive data for the first two seconds after answering an incoming call. 1.65.3 Equipment 1. Applicable loop simulator SEL#4. 2. Digital sampling storage oscilloscope SEL#24. 3. Data generator SEL#18. 4. Ringing amplifier SEL#33. Note: Refer to subclause 5.5 for equipment details. 1.65.4 Equipment States Subject to Test Answering an incoming call, transmitting and receiving data (on hook to off -hook transition). 1.65.5 Procedure 1. Connect the EUT to the test circuit of Figure 12.2 1. 2. Set the oscilloscope to trigger on the transition from the on-hook to the off-hook state. Page 332 Telecommunications Industry Association TR41.9.1-10-05-002L 3. Apply the ringing signal to the EUT. 4. Monitor the signal transmitted by the EUT for at least two seconds after the on-hook to off-hook transition under normal operating conditions. Verify that data transmission is delayed for the required time. If a signal is observed in less than the required time, verify that it is one of the allowed signals. 5. Connect the EUT to the test circuit of Figure 12.2 2. 6. Set the EUT to receive data. 7. Set the oscilloscope to trigger on the transition from the on-hook to the off-hook state of the EUT. 8. Apply the ringing signal to the EUT. 9. Monitor the EUT to verify that it does not respond to the incoming data for the time specified in the test requirement after going off-hook (see comment). 1.65.6 Alternative Methods None suggested. 1.65.7 Suggested Test Data Verification of the data delay. 1.65.8 Comments It may not be possible to determine whether or not data has been received. Engineering analysis and attestation by the applicant may be necessary in these cases. Page 333 Telecommunications Industry Association TR41.9.1-10-05-002L 1. The companion terminal equipment should provide the termination for this test; therefore, R1 of the loop simulator may be removed. The loop simulator provides loop current for both the EUT and the companion equipment. 2. Refer to the figures of clause 1 of TIA-968-B. Figure 12.2-1. Call Duration, EUT, Transmit 1. The companion terminal equipment should provide the termination for this test; therefore, R1 of the loop simulator may be removed. The loop simulator provides loop current for both the EUT and the companion equipment. 2. Refer to the figures of clause 1 of TIA-968-B. Figure 12.2-2. Call Duration, EUT, Receive Page 334 Telecommunications Industry Association TR41.9.1-10-05-002L 1.66 On-hook Signal Power, Analog TIA-968-B, 4.4.2.1, 4.4.2.2 1.66.1 Background The -55 dBm or less transmission level specified for an on-hook condition is considered to be equivalent to no transmission. This requirement is intended to avoid the transmission of information without activating the billing equipment. 1.66.2 Purpose To verify that no signal is applied to the network when the EUT is in the on-hook state. 1.66.3 Equipment 1. Applicable loop simulator SEL#4. 2. Bandpass filter SEL#5. 3. True rms AC Voltmeter SEL#40. Note: Refer to subclause 5.5 for equipment details. 1.66.4 Equipment States Subject to Test On-hook state. 1.66.5 Procedure 1.66.5.1 For Terminal Equipment: 1. Connect the EUT to the test circuit of Figure 12.3-1 using the 200 Hz to 4000 Hz bandpass filter and voltmeter. 2. Place the EUT in the on-hook state. 3. Measure and record the maximum signal power level in dBm. 4. Verify that the signal level is less than the limit. Page 335 Telecommunications Industry Association TR41.9.1-10-05-002L 1.66.5.2 For Protective Circuits: 1. Connect the EUT to the test circuit of Figure 12.3-2. 2. Place the EUT in its on-hook state. 3. Adjust the input signal to the EUT to 1000 Hz at a level at least 10 dB above the overload point. 4. Measure and record the output signal power level in dBm. 1.66.6 Alternate Methods 1.66.6.1 For Terminal Equipment: (1) Connect the EUT to the test circuit of Figure 12.3-1 and replace the bandpass filter and true rms AC voltmeter with a signal analyzer (SEL#56). (2) Set the signal analyzer to measure the following: (a) Signal level in dBm, 600 ohms. (b) Averaging over 3 second. (c) Band pass power in the frequency range of 200 Hz to 4000 Hz band. Note: Signal Analyzer should provide a balanced input, or an isolation transformer may be used. (3) Place the EUT in the on-hook state and measure and record the maximum signal power level. 1.66.7 Suggested Test Data 1. For terminal equipment, on-hook signal power level in dBm. 2. For protective circuitry, record the input level in dBV and the output level in dBm. 1.66.8 Comments Page 336 Telecommunications Industry Association TR41.9.1-10-05-002L On-hook includes states where signal sources in the EUT are active but which are intended to be isolated from the network. 1. Select the appropriate loop simulator for the interface of the EUT. 2. Connect the bandpass filter across R1 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. Figure 12.3-1. On-hook Signal Power, TE 1. Select the appropriate loop simulator for the interface of the EUT. 2. Connect the bandpass filter across R1 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 4. The frequency generator is only required for testing protective circuitry. Figure 12.3-2. On-hook Signal Power, PC Page 337 Telecommunications Industry Association TR41.9.1-10-05-002L 1.67 Off-Hook Loop Current TIA-968-B, 5.1.11.4, 5.1.12.4 1.67.1 Background The loop current restriction for the first five seconds, and subsequent requirements, are necessary to ensure connection and operation of the billing equipment of the telephone company. 1.67.2 Purpose To measure the off-hook DC current drawn by the EUT from the loop simulator in the first five seconds after the on-hook to off-hook transition. 1.67.3 Equipment 1. Applicable loop simulator SEL#4. 2. DC current meter SEL#19. 3. Digital sampling storage oscilloscope SEL#24. 4. Frequency generator SEL#27 (if required). 5. Ringing amplifier SEL#33 (if required). Note: Refer to subclause 5.5 for equipment details. 1.67.4 Equipment States Subject to Test The first five seconds after the EUT transfers from the on-hook to the off-hook state in response to an incoming call. Page 338 Telecommunications Industry Association Page 339 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.67.5 Procedure Note: Either of the two following methods can be used: 1.67.5.1 Method A: Comparison With Current through a 200 ohm Resistor 1. Connect the EUT to the test circuit of Figure 12.4-1. 2. Set the DC voltage of the loop simulator to 42.5 V DC. 3. Set switch S1 to position "A”. 4. Adjust resistor R2 of the loop simulator to 1740 ohms and record the loop current through the 200 ohm resistor. 5. Set switch S1 to position "B”. 6. Cause the EUT to go off-hook. 7. Monitor the DC current for the first five seconds after transferring from the on-hook to the off-hook state. Record the minimum current level during the first five seconds. 8. If the DC current drawn by the EUT is equal to or greater than the DC current measured in step (4), then the requirement is met. 1.67.5.2 Method B: Percent Change in DC Current 1. Connect the EUT to the test circuit of Figure 12.4-2. 2. Place the EUT in its off-hook condition and adjust resistance R2 to its maximum value and adjust the source voltage to its minimum value (1740 ohms, 42.5 V DC). 3. Place the EUT in its on hook state. 4. Set the oscilloscope to trigger on the transition from on hook to off-hook of the EUT. 5. Cause the EUT to go off-hook. Page 340 Telecommunications Industry Association TR41.9.1-10-05-002L 6. Monitor voltage across the 10 ohm resistor for the first five seconds after transferring the EUT from the on-hook state to the off-hook state. Record the maximum and minimum voltage levels. 7. The percent change in current will be equal to the percent change in voltage of the minimum voltage level relative to the maximum voltage during the first five seconds. 8. Set R2 set to its minimum value and adjust the source voltage to its maximum value (400 ohms, 56.5 V DC). 9. Repeat Step (3) through Step (7). 10. Set R2 to a value that produces a mid-range current and adjust the source voltage to its maximum value (1200 ohms, 52.5 V). 11. Repeat Step (3) through Step (7). 1.67.6 Alternative Methods None suggested. 1.67.7 Suggested Test Data 1.67.7.1 Method A: Comparison with 200 ohm Resistor 1. Loop current measured with 200-ohm resistor (mA DC). 2. Loop current measured with EUT (mA DC). 3. Comparison of loop currents. 4. Resistor R2 range. 1.67.7.2 Method B: Percent Change in Loop Current 1. Maximum and minimum off-hook DC voltage during the first five seconds. 2. Percent change during first five seconds. 3. Resistor R2 range. Page 341 Telecommunications Industry Association TR41.9.1-10-05-002L 1.67.8 Comments 1. Chart recorder can be used in place of oscilloscope. 2. A DC current probe may be used with the oscilloscope to monitor current instead of voltage. 1. Only the DC portion of the loop simulator circuit should be connected for this test. 2. Loop current is measured with a current meter in series with R2 of the loop simulator Refer to the figures of clause 1 of TIA-968-B. Figure 12.4-1. Loop Current, 200 ohm Method 1. Only the DC portion of the loop simulator circuit should be connected for this test. 2. Refer to the figures of clause 1 of TIA-968-B. Figure 12.4-2. Loop Current, 25% Method Page 342 Telecommunications Industry Association Page 343 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.68 Signaling Interference, Analog TIA-968-B, 4.4.3.1 1.68.1 Background This requirement is necessary so that the equipment does not interfere with the 2600 Hz billing signal. The signaling interference requirements only apply to the first two seconds after the called station goes off-hook in response to an incoming alerting signal. The 2600 Hz limitation is required to ensure adequate time for the connection and operation of billing equipment. Failure to comply with this requirement after the first two seconds will result in operational problems and is self correcting (see also FCC Public Notice 9160, Ref A10 in subclause 3). 1.68.2 Purpose To verify that the signal power generated in the 2450 Hz to 2750 Hz frequency band is no greater than that generated in the 800 Hz to 2450 Hz frequency band for the first two seconds. 1.68.3 Equipment 1. Applicable loop simulator SEL#4. 2. Bandpass filter SEL#6. 3. Bandpass filter SEL#7. 4. Frequency generator SEL#27 (if required). 5. Ringing amplifier SEL#33 (if required). 6. True rms AC voltmeter SEL#40. Note: Refer to subclause 5.5 for equipment details. 1.68.4 Equipment States Subject to Test Test the first two seconds after the EUT goes off-hook in response to receiving an alerting signal. Page 344 Telecommunications Industry Association TR41.9.1-10-05-002L 1.68.5 Procedure 1. Connect the EUT to the test circuit of Figure 12.5-1. 2. Select the bandpass filter for the 800 Hz to 2450 Hz band. 3. Initiate a call into the EUT. 4. Measure the maximum signal power in dBm after the EUT goes off-hook for the first two seconds. 5. Return the EUT to its on-hook state. 6. Select the bandpass filter for the 2450 Hz to 2750 Hz band. 7. Initiate a call into the EUT. 8. Measure the maximum signal power in dBm after the EUT goes off-hook for the first two seconds. 9. Compare the energy in the 2450 Hz to 2750 Hz band to the energy in the 800 Hz to 2450 Hz band. 10. Repeat Step (2) through Step (9) for all other call answering modes, if applicable. 1.68.6 Alternative Methods (1) Connect the EUT to the test circuit of Figure 12.5-1 and replace the bandpass filter and true rms AC voltmeter with a signal analyzer (SEL#56). (2) Set the signal analyzer to measure the following: 4. Signal level in dBm, 600 ohms. 5. Averaging over 2 seconds. 6. Band pass power in the frequency range of 800 Hz to 2450 Hz band. Note: Signal Analyzer should provide a balanced input, or an isolation transformer may be used. 3. Initiate a call into the EUT. Page 345 Telecommunications Industry Association TR41.9.1-10-05-002L 4. Measure the maximum signal power in dBm after the EUT goes off-hook for the first two seconds. 5. Return the EUT to its on-hook state. 6. Set the band pass power of the Signal Analyzer to the frequency range of 2450 Hz to 2750 Hz band. 7. Initiate a call into the EUT. 8. Measure the maximum signal power in dBm after the EUT goes off-hook for the first two seconds. 9. Compare the energy in the 2450 Hz to 2750 Hz band to the energy in the 800 Hz to 2450 Hz band. 10. Repeat Step (3) through Step (9) for all other call answering modes, if applicable. 1.68.7 Suggested Test Data 1. 800 Hz to 2450 Hz band energy. 2. 2450 Hz to 2750 Hz band energy. 3. Signal power levels in dBm. 1.68.8 Comments 1. Two bandpass filters and two voltmeters may be used so that measurements in the two bands can be taken simultaneously. 2. A voltmeter or signal analyzer that can be triggered by the on-hook to off-hook transition is helpful. 3. Refer to subclause 4.8.1 of TIA-968-B for conditions where data equipment is exempt from this requirement. Page 346 Telecommunications Industry Association TR41.9.1-10-05-002L 1. Select the appropriate loop simulator for the interface of the EUT. 2. Connect the bandpass filter across R1 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. 3. Loop current is measured with a current meter in series with R2 of the loop simulator. Refer to the figures of clause 1 of TIA-968-B. Figure 12.5-1. Signaling Interference Page 347 Telecommunications Industry Association TR41.9.1-10-05-002L 1.69 Signaling Interference, Digital TIA-968-B, 4.4.3.2 1.69.1 Background Transmission of analog signals in the band about 2600 Hz may interfere with the proper operation of network billing equipment unless an equal or greater amount of energy is present in the guard band. Therefore, the 2600 Hz energy in encoded analog signals that are decoded and transmitted on the analog network needs to be controlled. The requirements of this subclause apply to the called station during the first two seconds of connection. 1.69.2 Purpose To verify that the signal power contained in the encoded analog signal in the signaling band (2450 Hz to 2750 Hz) is less than or equal to the power contained in the guard band (800 Hz to 2450 Hz). 1.69.3 Equipment 1. Bandpass filter SEL#6. 2. Bandpass filter SEL#7. 3. Companion terminal equipment SEL#15. 4. Multiplexer/demultiplexer SEL#32. 5. True rms AC voltmeter SEL#40 (qty 2). 6. Zero-level encoder/decoder SEL#46. Note: Refer to subclause 5.5 for equipment details. 1.69.4 Equipment States Subject to Test The EUT is to be active and transmitting the encoded analog signal. The test is to be performed on internally generated signals other than DTMF signals that the EUT can transmit in the first two seconds after the EUT goes off-hook in response to receiving an alerting signal. Page 348 Telecommunications Industry Association TR41.9.1-10-05-002L 1.69.5 Procedure 1. Connect the EUT to the test circuit of Figure 12.6-1. As shown, two types of signals may be transmitted: 1. Internally generated signals that are generated directly in digital form but which are intended for eventual conversion to analog form; 2. Internally generated analog signals that are converted to digital format for eventual reconversion to analog form. 2. For signals of type (a) or type (b) as described above, cause the equipment to generate each of the possible signals in the first two seconds after the EUT goes off-hook. 3. Read the signal energy in the 800 Hz to 2450 Hz band. 4. Read the signal energy in the 2450 Hz to 2750 Hz band. 5. Repeat Step (3) and Step (4) for all other call answering modes, if applicable.. 1.69.6 Alternative Methods 1. Connect the EUT to the test circuit of Figure 12.6-1 and replace the bandpass filters and true rms AC voltmeters with a signal analyzer (SEL#56). 2. Set the signal analyzer to measure the following: 1. Signal level in dBm, 600 ohms. 2. Averaging over 2 seconds. 3. Band pass power in the frequency range of 800 Hz to 2450 Hz band. Note: Signal Analyzer should provide a balanced input, or an isolation transformer may be used. 3. For signals of type (a) or type (b) as described above, cause the equipment to generate each of the possible signals in the first two seconds after the EUT goes off-hook. 4. Measure the maximum signal power in dBm after the EUT goes off-hook for the first two seconds. Page 349 Telecommunications Industry Association TR41.9.1-10-05-002L 5. Read the signal energy in the 800 Hz to 2450 Hz band. 6. Set the band pass power of the Signal Analyzer to the frequency range of 2450 Hz to 2750 Hz band. 7. Read the signal energy in the 2450 Hz to 2750 Hz band. 8. Repeat Step (3) through Step (7) for all other call answering modes, if applicable. 1.69.7 Suggested Test Data 1. The signal which was measured. 2. The signal power contained in the band from 800 Hz to 2450 Hz . 3. The signal power contained in the band from 2450 Hz to 2750 Hz . 1.69.8 Comments 1. A 600 ohm termination should be applied at the input of the filter, and the voltmeter should be unterminated. 2. Simultaneous measurement of the signal power contained in each band is preferred. 10. Figure 12.6-1. 1.544 Mb/s, Signaling Interference Page 350 Telecommunications Industry Association Page 351 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.70 On-Hook Signal Power, Subrate and 1.544 Mb/s TIA-968-B, 4.4.2.3 1.70.1 Background These requirements define the on-hook conditions in terms of encoded analog signal power. The -55 dBm limit ensures that no useful information is exchanged when the associated analog equipment displays an on-hook condition to the network. Reverse battery is used on one-way incoming trunks from a telephone company to a PBX (known as direct inward dialing trunks). In this case, the digital facility would have to be part of such a trunk connection. 1.70.2 Purpose To verify the equivalent analog level content in the on hook state for Subrate, 1.544 Mb/s terminal equipment, 1.544 Mb/s protective circuitry and 1.544 Mb/s reverse battery. 1.70.3 Equipment 1. Companion terminal equipment SEL#15. 2. Multiplexer/demultiplexer SEL#32. 3. True rms AC voltmeter SEL#40. 4. Zero-level encoder/decoder SEL#46. Note: Refer to subclause 5.5 for equipment details. 1.70.4 Equipment States Subject to Test The EUT is to be in the on-hook state and transmitting the on-hook digital signal. Page 352 Telecommunications Industry Association TR41.9.1-10-05-002L 1.70.5 Procedure 1. Connect the EUT to the test circuit of Figure 12.7-1. 2. Cause the digital equipment to transmit the on-hook signal. 3. Measure the signal power as derived at the output of the zero-level decoder or companion terminal equipment. 1.70.6 Alternative Methods (1) Connect the EUT to the test circuit of Figure 12.7-1 and replace the bandpass filter and true rms AC voltmeter with a signal analyzer (SEL#56). (2) Set the signal analyzer to measure the following: 7. Signal level in dBm, 600 ohms. 8. Averaging over 3 seconds. 9. Band pass power in the frequency range of 200 Hz to 4000 Hz band. Note: Signal Analyzer should provide a balanced input, or an isolation transformer may be used. (3) Place the EUT in the on-hook state and measure and record the maximum signal power level. 1.70.7 1.544 Mb/s Protective Circuits 5. Connect the EUT to the test circuit of Figure 12.7-1 6. Place the EUT in its on-hook state. 7. Provided an 1000 Hz input signal to the EUT at a level at least 10 dB above the overload point. (4) Measure and record the output signal power level in dBm. 1.70.8 Suggested Test Data The measured on-hook signal level in dBm with respect to 600 ohms. Page 353 Telecommunications Industry Association TR41.9.1-10-05-002L 1.70.9 Comments On-hook includes states where signal sources in the EUT are active but which are intended to be isolated from the network. Figure 12.7-1. Subrate and 1.544 Mb/s, On-hook Level Page 354 Telecommunications Industry Association Page 355 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.71 Signaling Duration, 1.544 Mb/s TIA-968-B, 4.4.1 1.71.1 Background This requirement ensures that the off-hook signal to the network persists for at least five seconds, unless the terminal equipment actually returns to the on-hook state. This is the maximum time required to set up a call in a CO (including high speed automatic dialing by terminal equipment) and properly record the initial billing information (calling and called numbers). 1.71.2 Purpose To verify the minimum active signaling duration. 1.71.3 Equipment 1. Companion terminal equipment SEL#15. 2. Multiplexer/demultiplexer SEL#32. 3. Zero-level encoder/decoder SEL#46. Note: Refer to subclause 5.5 for equipment details. 1.71.4 Equipment States Subject to Test Place the device in the off-hook state in response to the alerting signal. 1.71.5 Procedure 1. Connect the EUT to the test circuit of Figure 12.8-1. 2. Apply incoming alerting signaling to the input of the EUT. 3. Cause the EUT to respond to the incoming signaling by whatever means are normal for the equipment; for example, by answering the call at the system console or by seizure of the associated analog channel. Page 356 Telecommunications Industry Association TR41.9.1-10-05-002L 4. Immediately remove the alerting signal. 5. Monitor the outgoing signaling bits from the digital equipment or the state of the associated companion terminal equipment for a minimum of 5 seconds to assure that the EUT continues to transmit the signaling bit sequence representing the off-hook state for 5 seconds, unless the EUT is returned to the on-hook state during the 5-second interval. 1.71.6 Alternative Methods None suggested. 1.71.7 Suggested Test Data State whether the digital equipment complies with this requirement. 1.71.8 Comments This test applies only to channelized 1.544 megabits per second (Mb/s) digital equipment. Figure 12.8-1. 1.544 megabits per second (Mb/s), Signaling Duration Page 357 Telecommunications Industry Association Page 358 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.72 Operating Requirements for DID TIA-968-B 5.1.1.3.4, 5.2.4.9 1.72.1 Background This requirement ensures that the off-hook signal to the network interface commences within 0.5 seconds of the called station answering the call. The requirement is necessary to initiate billing. 1.72.2 Purpose To verify that terminal equipment signals the network upon entering the off-hook state. 1.72.3 Equipment 1. Companion Terminal Equipment SEL#15. 2. Digital sampling storage oscilloscope SEL#23. 3. Digital DC voltmeter SEL#22 4. Zero-level encoder/decoder SEL#46. 1.72.4 Equipment States Subject to Test Place the TE in an off-hook state in response to an incoming call. 1.72.5 Test Procedure 1.72.5.1 Test Procedure for Analog DID 1. Connect the companion terminal equipment and the digital DC voltmeter to the tip and ring leads of the EUT as shown in Figure 12.9.5.1-1. 2. Connect the digital DC voltmeter across the tip and ring leads of the EUT. 3. Connect the companion terminal equipment (e.g. a telephone) to the called station under test. Page 359 Telecommunications Industry Association TR41.9.1-10-05-002L 4. Connect channel 1 of the storage oscilloscope (between ring lead and ground) to the EUT. 5. Connect channel 2 of the storage oscilloscope (between ring lead and ground) to the called station under test. 6. Originate a direct inward dialing call from the companion terminal equipment. 7. Monitor the EUT line loop polarity with the digital DC voltmeter. 8. Observe and record with the storage oscilloscope the elapsed period between the time the called PBX station goes off-hook to answer the call and the time that the EUT transmitted the line reversed answer supervision signal to the network. 9. Ensure that the line reversed answer supervision state maintains for the duration of the call. 10. Repeat steps (6) through Step (9) for each call answering mode (i.e. answered by the attendant, answered by a recorded message, forwarded call to another trunk, etc). 1.72.5.2 Test Procedure for Digital DID 1. Connect the TE to the test circuit of Figure 12.9.5.2-1. 2. Activate the A&B bits on the Zero Level encoder to simulate an incoming call on the Reverse Battery DSO Channel under test. 3. Monitor the A&B bits transmitted by the TE and the Tip and Ring leads of the called station. 4. Observe and measure the elapsed period between the time that the called station goes offhook to answer the call and the time that the TE transmitted A&B bits’ changes to answer supervision status. 5. Ensure that the A&B bit status remains in the answer supervision mode for the duration of the call. 6. Repeat steps (2) through (5) for each call answering mode as specified by the requirements, i.e. answered by the attendant, answered by a recorded message, forwarded call to another trunk, etc. Page 360 Telecommunications Industry Association TR41.9.1-10-05-002L 1.72.6 Alternative Methods None suggested. 1.72.7 Suggested Test Data State whether the TE complies with this requirement. 1.72.8 Comments This requirement applies only to equipment with Direct Inward Dialing interfaces. Figure 12.9.5.1-1. Analog Direct Inward Dialing Page 361 Telecommunications Industry Association Page 362 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L Note: This procedure shows using the oscilloscope to monitor the “A” and “B” bits. This may be done by many means (e.g. a function within the zero level encoder/decoder). Figure 12.9.5.2-1 1.544 megabits per second (Mb/s) Direct Inward Dialing 1.72.9 Page 363 Telecommunications Industry Association Page 364 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L Connectors Environmental and operational considerations require the use of contact interface materials that result in a quality electrical connection. A quality electrical connection is corrosion resistant and provides low noise and low contact resistance under normal network operating conditions. Because of its unique characteristics, gold has typically been used for this type of application. To allow for advances in technology, the FCC permitted the use of non-gold interface materials so long as they were compatible with each other and with gold, and of equivalent performance to gold. 1.73 Gold Contact Interface A contact interface that uses gold as the principal contact interface material needs to meet the requirements and test methods in TIA-1096. The gold contact interface definition in TIA-1096 is not intended to limit the gold contact interface to one that is produced by a plating process. Gold contact interfaces produced by other processes such as "cladding" that meet all the requirements of TIA-1096 for material quality, thickness, density, porosity and surface roughness are to be considered the same as an acceptable plated gold interface. 1.74 Non-gold Contact Interface In Docket No. 88-57, the FCC requested the Electronics Industries Association (EIA) to develop a procedure for demonstrating the equivalency of alternative contact materials to hard gold for 6 and 8 position connectors. In 1989, TIA Subcommittee TR-41.9 included such a procedure in its Telecommunications Systems Bulletin EIA/TIA TSB-31 on suggested Part 68 test methods. Requirements and test methods for demonstrating the equivalency of alternative contact materials to hard gold are now provided in TIA-1096. Page 365 Telecommunications Industry Association TR41.9.1-10-05-002L OTHER TYPES OF DSL TERMINAL EQUIPMENT 1.75 Metallic Signals TIA-968-B 5.3.1.1, 5.3.4.1, 5.3.5.1, 5.3.5.2, 5.3.6.1, 5.3.7.1, 5.3.8.1, 5.3.9.1 1.75.1 Background This section currently only provides test procedures for SHDSL, ESHDSL, HDSL2, and HDSL4 terminal equipment. Similar procedures may be applicable to other types of DSL terminal equipment. SHDSL, ESHDSL, HDSL2, and HDSL4 terminal equipment transmit significant power in and above the voiceband and do not support the use of analog splitting technology for coexistence on the same pair with voiceband services. Therefore, the analog voiceband signal power limits in TIA-968-A are not applicable to SHDSL, ESHDSL, HDSL2, or HDSL4 terminal equipment. Likewise, SHDSL, ESHDSL, HDSL2, and HDSL4 terminal equipment would not ordinarily conform to the signal power specifications for any of the other services or interfaces defined in section 4.5 of TIA-968-A. 1.75.2 Purpose To verify that the PSD is below the mask and to verify total signal power transmitted to the network is properly limited. 1.75.3 Equipment (1) Vector analyzer SEL#62 (2) Hi-pass filter SEL#63 (3) Balun transformers SEL#64, #65, #66 (4) Artificial line SEL#67 NOTE: Refer to Section 5.3 for equipment details. Page 366 Telecommunications Industry Association TR41.9.1-10-05-002L 1.75.4 Equipment States Subject to Test Transmitting continuously at all line data rates at maximum transmit power. Page 367 Telecommunications Industry Association Page 368 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.75.5 Procedure Measure the First PSD Segment & Total Power: (1) Connect the EUT (TU-R) to the companion unit (TU-C) as shown in Figure 14.1-1. (2) Using the artificial line, allow the EUT and TU-C to synchronize at maximum power. When the DSL link has trained up, cause the EUT to continue to transmit constantly without connection to the TU-C. (3) Connect the EUT (TU-R) to the measurement equipment as shown in Figure 14.1-2. (4) Set the vector analyzer frequency range and band power markers at 1 kHz (start) and 2 MHz (stop). Resolution bandwidth = 10 kHz, Averaging time 10 seconds, Reference level: 20 dBm/Hz, dB/div: 10 dB and Autorange. If applicable, load the PSD for the appropriate data rate (R), onto the vector analyzer. Alternatively, comparison with the PSD mask can be done later, if your vector analyzer lacks this capability. Note: See comments for PSD masks. (5) Measure and record the PSD and total power between 1 kHz and 2 MHz. No filter is required. Notes: (1) For HDSL2 the band power markers would be set to 1 kHz and 350 kHz for the total power measurement. (2) For HDSL4 set the vector analyzer start frequency at 200 Hz (start) and the band power markers to 200 Hz and 307 kHz for the total power measurement, using the SEL#65 balun. Measure the Second PSD Segment: (6) Insert a high-pass filter (in accordance with the table below) into the setup BNC) is needed for the balun with most active filters, since they have high input impedance. Page 369 Telecommunications Industry Association TR41.9.1-10-05-002L (7) Set the vector analyzer frequency range in accordance with the following table. There is some overlap with the range covered in steps (3) though (5), but it is often necessary to “close in” on this part of the signal with a filter to eliminate the pass band signal, and with a lower range setting. Resolution bandwidth = 10 kHz, Averaging time 10 seconds, Reference level: -50 dBm/Hz, dB/div: 10 dB and Autorange. If applicable, load the PSD mask for the appropriate data rate (R), onto the vector analyzer. Alternatively, comparison with the PSD mask can be done later, if your vector analyzer lacks this capability. Measure and record the PSD as follows: Technology Frequency Range High Pass Filter Setting R < 2Mbps = 350 kHz SHDSL (16-TCPAM) 500 kHz to 10 MHz ESHDSL 500 kHz to 10 MHz fint – 100kHz (Note 2) HDSL2 500 kHz to 10 MHz 350 kHz HDSL4 2MHz to 10 MHz 350 kHz R > 2Mbps = 600 kHz Notes: (1) The start frequency on the analyzer and the cut-off frequency on the filter can be adjusted as necessary, keeping in mind that the effects of the filter are not within the window of measurement. (2) fint is the frequency where the two functions governing PSDMASK SHDSL(f) intersect. fint may be approximated by the following formulas: 16-TCPAM = (R+8)/3 32-TCPAM = (R+8)/4 Page 370 Telecommunications Industry Association TR41.9.1-10-05-002L Measure sliding 1 MHz window (WS) power criteria: (8) Without changing the setup from step (7), measure the total power in accordance with the following table . If the reading is less than -50 dBm, stop and record. If the reading is greater than -50 dBm, break into smaller windows of 1MHz, and record the highest reading from all windows. Technology 1 MHz Sliding Window Frequency Range SHDSL (16-TCPAM) 1.1 MHz to 10 MHz ESHDSL (16-TCPAM) fint to 10 MHz ESHDSL (32-TCPAM) fint to 10 MHz HDSL2 3.1 MHz to 10 MHz HDSL4 Not Applicable Measure the Third PSD Segment from 10 MHz to 30 MHz (12 MHz for ESHDSL): (9) Use balun SEL#66 and filter settings as appropriate (see note (4) of Figure 14-1). (10) Set the vector analyzer frequency range and band power markers at 10 MHz (start) and 30 MHz (stop). Resolution bandwidth = 100 kHz (10 kHz for ESHDSL), Averaging time 10 seconds, Reference level: -50 dBm/Hz, dB/div: 10 dB and Autorange. If applicable, load the PSD mask for the appropriate data rate (R), onto the vector analyzer. Alternatively, comparison with the PSD mask can be done later, if your vector analyzer lacks this capability. Note: It may be necessary to break this band up further, depending on the instruments selected. (11) Measure and record the PSD between 10 MHz and 30 MHz (with the exception of ESHDSL that ends at 12 MHz). Page 371 Telecommunications Industry Association TR41.9.1-10-05-002L Measure sliding 1 MHz window (WS) power criteria in the 10 MHz-30 MHz band (12 MHz for ESHDSL): (12) Without changing the setup from step (11), use the band power markers to measure the total power in the window from 10 MHz to 30 MHz (12 MHz for ESHDSL). If the reading is less than -50 dBm, stop and record. If the reading is greater than -50 dBm, break into smaller windows of 1 MHz, and record the highest reading from all windows. 1.75.6 Alternative Method A spectrum analyzer (SEL #57) may be used instead of the Vector Analyzer. A high pass filter is preferred for measurements above the operating band. The signal power may be calculated by integrating the PSD over the operating band. The PSD may be compared against the limit by using a spreadsheet or other software applications. The spreadsheet may also be used to calculate the total power over a 1 MHz sliding window. 1.75.7 Suggested Test Data (1) Plots of the PSD for each line rate with the limit line shown on each graph. (2) Total Signal Power Level. (3) Line Data Rate and Baud Rate if applicable. 1.75.8 Comments (1) Watch the dynamic range on each measurement. Make sure proper dynamic range is selected for each measurement. (2) Filter type should ideally yield a 0dB gain, flat, in all areas of measurement. The filter is present only to prevent the strong passband signal from overloading the front end of the analyzer, and reducing its ability to range down. Page 372 Telecommunications Industry Association TR41.9.1-10-05-002L (3) Equipment that is classified as G.SHDSL according to clauses 5.4.2 and 6.3.2 of T1.4172003, the PSD mask (SHDSLM(f)) can be calculated from the following: MaskedOffsetdB(f) is defined as: fint is the frequency where the two functions governing SHDSLM(f) intersect in the range 0 to fsym. KSHDSL, fsym, f3dB, and the line bit rate LBR are defined in Table 15 of T1.417-2003. The G.SHDSL PSD and total average power is measured with a termination of 135 Ohms. (4) Equipment that is classified as HDSL2 (SMC 4) according to clause 5.3.4 and 6.2.4 of T1.417-2003, the PSD mask can be determined from Table 6 and Figure 5 of T1.4172003. The HDSL2 PSD and total average power is measured with a termination of 135 Ohms. (5) Equipment that is classified as HDSL4 according to clause 5.4.3 and 6.3.3 of T1.417-2003, the PSD mask can be determined from Table 18 and Figure 15 of T1.417-2003. The HDSL2 PSD and total average power is measured with a termination of 135 Ohms. (6) ESHDSL PSD mask can be determined from clause 4.5.9.2.4 of TIA-968-A-4. The ESHDSL PSD and total average power is measured with a termination of 135 Ohms. Figure 14.1-1 Test Configuration to Establish Data Mode Notes: (1) In practice, two transformers are typically used. One for 1kHz < f < 10 MHz, and another for 5 MHz < f < 30MHz. (There is some overlap in measurements). Page 373 Telecommunications Industry Association TR41.9.1-10-05-002L (2) In practice, two settings are used. The filter is set to high-pass, 350 kHz for measurements in the 500 kHz < f < 10 MHz band, for data rates below 2Mbps. The filter is set to high-pass, 600 kHz for measurements in the 700 kHz < f < 10 MHz band, for data rates above 2Mbps. (3) No high-pass filter is used for 1 kHz < f < 500 kHz because this is in the passband. (4) A high-pass filter may or may not be needed for 10 MHz < f < 30 MHz, depending on the dynamic range of your instrument for these frequencies. If a filter is needed, use the same settings as for the 500 kHz/700 kHz < f < 10MHz band. Figure 14.1-2 Test Configuration to Measure PSD and Total Power 1.76 Longitudinal Output Voltage Limits TIA-968-B 5.3.1.3, 5.3.4.3, 5.3.5.4 , 5.3.6.3, 5.3.7.3, 5.3.8.3, 5.3.9.3 1.76.1 Background Longitudinal output voltage (LOV) limits complement PSD limits by restricting the amplitude of common mode signals much like the PSD limits restrict the amplitude of the equipment’s differential mode signals. LOV limits are necessary, as common mode signals tend to couple more readily than differential mode signals in multi-line, twisted pair cable plant. In other words, LOV limits are necessary to limit crosstalk. 1.76.2 Purpose To verify that the longitudinal output voltage is below the limit. 1.76.3 Equipment (1) Vector analyzer SEL#62 Note: Refer to Section 5.3 for equipment details. Page 374 Telecommunications Industry Association TR41.9.1-10-05-002L 1.76.4 Equipment States Subject to Test Transmitting continuously at its highest signal power and upstream line data rate. 1.76.5 Procedure (1) Condition the EUT to transmit at it highest upstream signal power level and line rate as described in 14.1.5 steps (1) and (2). (2) Connect the EUT to the test circuit of Figure 14.2-1. (3) Set the vector analyzer frequency range at 1 kHz (start) and 2.5 MHz (stop) and set the band power markers to 1 kHz and the upper -30 dB frequency, relative to peak PSD (“Operating Band”). For SHDSL at its highest data rate, this would be 565.5 kHz. Resolution bandwidth = 3 kHz, Averaging time 1 second, Reference level: -30 dBV, dB/div: 10 dB and Autorange. For HDSL2 refer to Table 6 of T1.417-2003 to determine the frequency range of the “Operating Band.” For HDSL4 refer to Table 18 of T1.417-2003 to determine the frequency range of the “Operating Band.” For ESHDSL refer to Clause 4.5.9.2.3 of TIA-968-A-4 to determine the frequency range of the “Operating Band.” (4) If reading is less than -50 dBV between band power markers, stop and record. If the reading is greater than -50 dBV, break into smaller windows of 3 kHz, and record the highest reading from all windows. Apply a correction factor of -1.3 dB to discrete readings obtained with a 3 kHz bandwidth for comparison against the LOV limit as specified over a 4 kHz bandwidth. (5) Set the vector analyzer band power markers from the upper -30 dB (relative to peak PSD) frequency to 4 the upper -30 dB frequency. For SHDSL at its highest data rate, this would be 565.5 kHz to 2262 kHz. Page 375 Telecommunications Industry Association TR41.9.1-10-05-002L (6) If reading is less than -80 dBV between band power markers, stop and record. If the reading is greater than -80 dBV, break into smaller windows of 3 kHz, and record the highest reading from all windows. Apply a correction factor of –1.3 dB to discrete readings obtained with a 3 kHz bandwidth for comparison against the LOV limit as specified over a 4 kHz bandwidth. (7) Repeat steps (3) though (6) for each of the data rates that the EUT can support. 1.76.6 Alternative Method A spectrum analyzer (e.g. SEL #57) may be used instead of the Vector Analyzer. If the spectrum analyzer does not have a 1 Mohm input impedance, then a correction factor may be necessary. 1.76.7 Suggested Test Data (1) Plot of the LOV with the limit line shown. (2) Line Data Rate and Baud Rate if applicable. 1.76.8 Comments (1) For this requirement, the operating band is the range of frequencies between the lower and upper -30 dB points (relative to peak PSD) of the signal passband as determined from the PSD masks. (2) Take care in the construction of the LOV test fixture. Test leads from the fixture to the EUT should be kept as short as possible to minimize RF ingress. Page 376 Telecommunications Industry Association TR41.9.1-10-05-002L NOTES: (1) The resistor values in Figure 14.2-1 are in ohms. (2) If the EUT does not have a ground connection or exposed grounded surface, it should be placed upon a ground plane that is also connected to earth ground (the same ground shared by the vector analyzer). Figure 14.2-1 LOV TEST FIXTURE & CONNECTION DIAGRAM Page 377 Telecommunications Industry Association Page 378 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.77 Transverse Balance TIA-968-B 5.3.2.2, 5.3.4.2, 5.3.5.3, 5.3.6.2, 5.3.7.2, 5.3.8.2, 5.3.9.2 1.77.1 Background See Subclause 10.1.1 1.77.2 Purpose To determine transverse balance of SHDSL, HDSL2 and HDSL4 EUTs. 1.77.3 Equipment 1. Spectrum analyzer SEL#34 2. Tracking generator SEL#39. NOTE: Refer to Subclause 5.5 for equipment details. 1.77.4 Equipment States Subject to Test Active state with appropriate grounding applied and the EUT transmitter turned off. 1.77.5 Procedure 3. Connect the EUT to the test circuit of Figure 10.2-1 with the 135 ohm calibration test resistor in place. (2) Set the spectrum analyzer and tracking generator to the appropriate frequency ranges: (see comment 1 and 2) (a) SHDSL EUT - 200 Hz to 490 kHz (b) HDSL2 EUT - 200 Hz to 422.1 kHz (c) HDSL4 EUT - 200 Hz to 493.6 kHz Page 379 Telecommunications Industry Association TR41.9.1-10-05-002L 4. Follow steps (3) through (13) in subclause 10.2.5. 1.77.6 Comments (1) For the purposes of this requirement, the applicable operating range is defined as the entire range of frequencies between the highest and lowest frequencies having PSD values within 20 dB of the peak PSD. Thus, the applicable frequency range for transverse balance testing varies depending upon the supported PSD masks. (2) Alternatively, a narrower frequency range may be used for SHDSL EUT that is defined by the points at which the measured power spectral density (PSD) is 20 dB down from the maximum level associated with both the maximum data rate of the upstream and downstream signals. (3) The longitudinal termination is defined in TIA-968-A-3, clause 4.6.5. Metallic source impedance and metallic voltage to be used for transverse balance measurements of SHDSL, HDSL2 and HDSL4 terminal equipment is 135 ohms (ZM) and 0.367 V (VM) for each of the supported PSD masks. Page 380 Telecommunications Industry Association TR41.9.1-10-05-002L 1.78 14.4 Conditioning VDSL/VDSL2 EUT to Transmit Continuously 1.78.1 14.4.1 General This subclause provides a suggested test procedure to measure aggregate signal power, power spectral density (PSD), and longitudinal output voltage (LOV) for VDSL/VDSL2 modems (VTU-R) against the applicable requirements specified in ANSI/TIA-968-B. 1.78.2 14.4.2 Conditioning the EUT to Transmit Continuously To properly measure aggregate signal power, PSD, and LOV, the EUT must be conditioned to transmit at its highest signal power level as allowed by the respective PSD masks without a sustained connection to companion equipment. The method of testing with a companion device is impractical for VDSL/VDSL2 equipment since the companion (VTU-C) equipment may present excessively high signal levels at frequencies at which the upstream PSD mask demands very low PSD levels. The amount of attenuation required to reduce the companion equipment’s signals below the upstream mask would be excessive to permit the link to come up at the maximum upstream signal power levels. This is because VDSL/VDSL2 equipment automatically reduces the line rate and power levels over long loops to maintain an acceptable level of performance. VDSL2 modems that support extended upstream operation must be tested against all of the spectral masks for all the operational modes that they support. There are two possible methods to achieve the required state for the VDSL/VDSL2 modem. One method involves a test mode via software whereby the EUT’s transmitter is forced to enter the showtime state without going through a training sequence. Showtime refers to the state where the VDSL/VDSL2 modem is transmitting a pseudorandom data pattern continuously. The other technique first involves bringing the VDSL/VDSL2 modem’s link up over an artificial line (see Figure 14.4-1) whose characteristics effectively force the EUT into its maximum signal power allowed by the PSD masks. Next, the EUT is strapped or conditioned to disable retrains so that once the showtime state has been achieved, the EUT may be disconnected from the artificial line and connected to a 100 ohm measurement termination. Using the artificial line technique, the EUT may need to be trained up with the VTU-C over various line loops to produce all of the EUT’s PSD upstream signals (US0, US1 & US2). For example for profile 12a: when the EUT is trained up over a 1000 ft loop it may only produce US1 and US2 PSD signals at their maximum level. When the EUT is trained up over a 3000 ft loop it may only produce US0 and US1 signals (US0 may not be at its maximum level). When the EUT is trained up over a 9000 ft loop it may only produce US0 PSD signal at its maximum level. The amount of line loops will vary from one vendor’s CPE to another and even with the same CPE if the start up margin is changed. Page 381 Telecommunications Industry Association TR41.9.1-10-05-002L Note: When setting the parameters of the artificial line, noise may be considered to be added to the line as it may play a key role in obtaining the maximum signal power. Figure 14.4-1. VDSL/VDSL2 conditioning setup Page 382 Telecommunications Industry Association Page 383 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.79 14.5 Signal Power Limitations, VDSL/VDSL2 Terminal Equipment ANSI/TIA968-B, 5.3.1.1 1.79.1 14.5.1 Background The aggregate signal or total power of the VDSL/VDSL2 modem must be limited to minimize near end crosstalk (NEXT) with other DSL systems that share the same cable binder. Crosstalk is widely recognized as a form of third party harm and represents the principal impairment to many DSL systems. 1.79.2 14.5.2 Purpose The purpose of this test is to verify that the signal power level transmitted to the network does not exceed the requirement. 1.79.3 14.5.3 Equipment RF power meter SEL#71. 100 ohm, 1 %, non-inductive resistor. Note: Refer to subclause 5.5 for equipment details. 1.79.4 14.5.4 Equipment States Subject to Test The equipment under test should be transmitting continuously at its highest obtainable signal power. For VDSL2 modems that support extended upstream operation, total signal power associated with each profile and EU designator should be measured. 1.79.5 14.5.5 Procedure 3. Condition the EUT to transmit its upstream signals at the highest power level as described in 14.4.2. Page 384 Telecommunications Industry Association TR41.9.1-10-05-002L 4. Connect the EUT to the test circuit of Figure 14.5-1. 5. Measure and record the signal power level in dBm. The level should be averaged over a time span of at least 10 seconds or longer if short term variations are observed. 6. Repeat steps 1 to 3 for each supported upstream profile and EU designator. 1.79.6 14.5.6 Alternative Method The total signal power may also be calculated by integrating the PSD over the operating band. This task consists of measuring the PSD over the operating band using a 10 kHz resolution bandwidth at discrete frequencies with a stepped interval of 10 kHz. The individual PSD readings are then converted to power readings by multiplying the PSD (in terms of watts/Hz) by the 10 kHz resolution bandwidth. This results in a power level for each 10 kHz window. These are then summed over the operating band to give the total power. Repeat this process for each supported upstream profile and EU designator. 1.79.7 14.5.7 Suggested Test Data Signal power level. Each profile and EU designator measured. Loop characteristics or test mode via software used to obtain the total power measurement. 1.79.8 14.5.8 Comments 1.79.9 If the RF power meter has a 50 ohm input impedance then a 50 to 100 ohm BALUN may be necessary. Care must be taken to ensure that measurement errors are kept to a minimum. Sources of error may include the following: Impedance deviations from the ideal 100 ohm termination BALUN loss (if used) Page 385 Telecommunications Industry Association TR41.9.1-10-05-002L Figure 14.5-1. Average Signal Power Note: If the RF power meter has 50 ohms input impedance, a 50 to 100 ohm BALUN (SEL#59) is needed and the 100 ohm resistor would be removed. Page 386 Telecommunications Industry Association Page 387 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.80 14.6 Power Spectral Density, VDSL/VDSL2 Terminal Equipment ANSI/TIA968-B, 5.3.8.1.3, 5.3.8.1.4 1.80.1 14.6.1 Background As is the case for the VDSL/VDSL2 modem’s total power, its PSD must be limited to minimize crosstalk. PSD is limited by the imposition of a PSD mask, which specifies a limit as a function of frequency. The mask permits a reasonable level in the operating bands while restricting the VDSL/VDSL2 modem’s PSD below the operating bands to protect POTS and above the operating bands both to minimize interference both with the downstream spectrum as well as other DSL systems potentially affected by crosstalk. The masks presents measurement challenges because it specifies such a broad range of signal levels, which can’t practically be made in a single sweep due to limitations in the spectrum analyzer’s dynamic range. For this reason and resolution bandwidth considerations, the mask is broken into two segments. 1.80.2 14.6.2 Purpose The purpose of this test is to verify that the transmitted PSD is below the PSD mask limits. 1.80.3 14.6.3 Equipment Spectrum analyzer SEL#57. 100:50 ohm BALUN transformer SEL#70 100:50 ohm BALUN transformer SEL#59. Note: Refer to subclause 5.5 for equipment details. 1.80.4 14.6.4 Equipment States Subject to Test The equipment under test should be transmitting continuously at its highest obtainable signal power. For VDSL2 modems that support extended upstream operation, total signal power associated with each profile and EU designator should be measured. Page 388 Telecommunications Industry Association TR41.9.1-10-05-002L 1.80.5 14.6.5 Procedure In this procedure the frequency range is divided into two segments. The number of segments chosen depends on the capabilities of the test equipment. Each frequency point in the operating bands (corresponding to a measurement in a single resolution bandwidth) of a PSD should be measured by averaging the power in the resolution bandwidth of that frequency point for a time period of at least 10 seconds. 1.80.5.1 14.6.5.1 Procedure for Segment 1 4. Condition the EUT to transmit US0 continuously as described in subclause 14.4.2. 5. Connect the EUT to the test circuit of Figure 14.6-1 using BALUN transformer SEL#70. 6. Set the spectrum analyzer as follows: Resolution bandwidth (RBW): 100 Hz Video bandwidth: 3 Hz Attenuation: Set for minimum without overload Reference level: (-20) dBm dB/div: 10 dB Marker function: Noise dBm/Hz Start frequency: 200 Hz Stop frequency: 25.875 kHz 7. Measure and record the PSD over the frequency range 200 Hz to 25.875 kHz. 8. Repeat steps 1 to 4 for each supported profile and extended upstream EU designator. Page 389 Telecommunications Industry Association Page 390 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.80.5.2 14.6.5.2 Procedure for Segment 2 3. Condition the EUT to transmit its upstream signals continuously as described in 14.4.2. 4. Connect the EUT to the test circuit of Figure 14.6-1 using BALUN transformer SEL#59. 5. Set the spectrum analyzer as follows: Resolution bandwidth: 10 kHz Video bandwidth: 3 kHz Attenuation: Set for minimum without overload Reference level: (0) dBm dB/div: 10 dB Marker Function: Noise dBm/Hz Start frequency: 25.875 kHz Stop frequency: 30 MHz 6. Measure and record the PSD over the frequency range 25.875 kHz to 30 MHz. 7. Repeat steps 1 to 4 for each supported profile and extended upstream EU designator. 1.80.6 14.6.6 Alternative Method None 1.80.7 14.6.7 Suggested Test Data 7. Measured PSD for each frequency range with the associated PSD limit line. 8. Each profile and EU designator measured. 9. Loop characteristics or test mode via software used to obtain the PSD measurement. 1.80.8 14.6.8 Comments (1) Care must be taken to ensure that measurement errors are kept to a minimum. Sources of error may include: Page 391 Telecommunications Industry Association TR41.9.1-10-05-002L Impedance deviations from the ideal 100 ohm termination BALUN loss Spectrum analyzer input clipping PSD measurement errors caused by excessively fast sweep times or not averaging enough samples when making a swept average measurement (2) Some spectrum analyzers may need a low-pass filter set to cut off frequency of 30 kHz for the Segment 1 measurement. (3) Some spectrum analyzers may need a high-pass filter to cut off the US0 frequency for the Segment 2 measurement. Figure 14.6-1. PSD Connection Diagram For Segments 1 & 2 Page 392 Telecommunications Industry Association Page 393 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.81 14.7 Transverse Balance, VDSL/VDSL2 ANSI/TIA-968-B, 5.3.8.2 1.81.1 14.7.1 Background See subclause 10.1.1. 1.81.2 14.7.2 Purpose To determine transverse balance of VDSL/VDSL2 EUT. 1.81.3 14.7.3 Equipment 3. Spectrum analyzer SEL#34 4. Tracking generator SEL#39 5. Transverse balance test fixture shown in Figure 14.7-1 Note: Refer to subclause 5.5 for equipment details. 1.81.4 14.7.4 Equipment States Subject To Test Active state with appropriate grounding applied and the EUT transmitter turned off. Note: Terminal equipment may require special attention to ensure it is properly configured for this test. For example, if the equipment would normally be connected to AC-power ground, cold-water-pipe ground, or if it has a metallic or partially metallic exposed surface, then these points are connected to the test ground plane. Similarly, if the EUT provides connections to other equipment through which ground may be introduced to the equipment, then these points are connected to the test ground plane. Equipment that does not contain any of these potential connections to ground are placed on a conductive plate that is connected to the test ground plane (see comment 1); this applies to both non powered and AC-powered equipment. Page 394 Telecommunications Industry Association TR41.9.1-10-05-002L 1.81.5 14.7.5 Procedure 2. Connect the 100 ohm calibration test resistor (RCAL) to the test circuit of figure 14.7-1. 3. Set the spectrum analyzer and tracking generator to the appropriate frequency ranges: 1. (a) For VDSL over POTS - 13.6 kHz to 12,000 kHz 2. (b) For VDSL2 over POTS profiles 8a, 8b, 8c, and 8d - 13.6 kHz to 8,500 kHz 3. (c) For VDSL2 over POTS profiles 12a and 12b - 13.6 kHz to 12,000 kHz 4. (d) For VDSL2 over POTS profiles 17a - 13.6 kHz to 20,000 kHz 5. (e) For VDSL2 over POTS profiles 30a - 13.6 kHz to 30,000 kHz 6. (f) For VDSL2 all digital mode profiles 8a, 8b, 8c, and 8d - 200 Hz to 8,500 kHz 7. (g) For VDSL2 all digital mode profiles 12a and 12b - 200 Hz to 12,000 kHz 8. (h) For VDSL2 all digital mode profiles 17a - 200 Hz to 20,500 kHz 9. (i) For VDSL2 all digital mode profiles 30a - 200 Hz to 30,000 kHz 2. Adjust the tracking generator voltage to measure a VM of 0.316 Vrms across the calibration test resistor of 100 ohm. 3. Connect the spectrum analyzer across the RL resistor (90 or 500 ohm as per ANSI/TIA968-B, Table 62). 4. Adjust the 20 pF differential capacitor until a minimum voltage across the RL resistor is obtained. This represents the highest degree to which the bridge can be balanced. The result of this balance calibration should be at least 20 dB better than the requirement for the applicable frequency band. If this degree of balance cannot be attained, further attention should be given to component selection for the test circuit and its construction. 5. Reverse the polarity of the tip-and-ring pair under test. If the transverse voltage (VL) changes by less than 1 dB, the calibration is acceptable. If the transverse voltage changes by more than 1 dB, it indicates that the bridge needs further adjustment to accurately measure the balance of the EUT. Repeat the calibration process until the measurements differ by less than 1 dB while maintaining the balance noted in step (5) above. Page 395 Telecommunications Industry Association TR41.9.1-10-05-002L 6. Replace the calibration resistor with the tip-and-ring pair of the EUT. 7. Measure the voltage across the tip and ring of the EUT; this is the metallic reference voltage (VM). 8. Measure the voltage across the RL resistor; this is the longitudinal voltage (VL). 9. Calculate the balance using the following formula: Note: If the readings are, for example, taken in dBV, then the equation may be simplified to: (11) Reverse the tip and ring connections of the EUT and repeat step (8) through step (10). The lesser of the two results is the transverse balance of the EUT. 1.81.6 14.7.6 Alternative Methods See Appendix C. Note: The test method that is described in Appendix C may be more appropriate to use for frequencies above 3 MHz. 1.81.7 14.7.7 Suggested Test Data 4. Frequencies tested. 5. Balance measured for the EUT. 6. Calibration balance measured. 1.81.8 14.7.8 Comments 2. EUT that is not normally grounded should be set in its normal position directly on a conductive plate. It is recommended that the overall area of the conductive plate be at least 50% greater than that of the base of the EUT. This represents the closest proximity to ground that is likely to be encountered by the EUT. 3. Interference from power frequency harmonics can be minimized by using test frequencies midway between multiples of 60 Hz. Page 396 Telecommunications Industry Association TR41.9.1-10-05-002L 4. In some cases, EUT may apply internally generated signals to the test set. Such signals should not be construed as part of the transverse balance test. 5. Test leads between the test fixture and the EUT will affect the calibration and EUT balance measurements. Such cables must be in place when making the calibration balance adjustments. T1 1:1 impedance ratio, 100 ohm wide-band transformer. 20pF Optimally a dual-stator air-variable RF capacitor that maintains a constant capacitance Differential between stators while providing a variable capacitance from either stator to ground. 3 pF Composition RF capacitor RCAL 100 ohms RL 90/500 ohms: A non-inductive precision resistor (chosen according to Table 62 of ANSI/TIA-968-B). 1. The 3 pF capacitor may be placed on either line of the test set, as required, to obtain proper balancing of the bridge. 2. The effective output impedance of the tracking generator should match the 100 ohms test impedance. The spectrum analyzer's input should be differentially balanced to measure V M. Figure 14.7-1 Transverse Balance, VDSL/VDSL2 Page 397 Telecommunications Industry Association 1.82 14.8 Longitudinal Output Voltage, ANSI/TIA-968-B, 5.3.8.3 TR41.9.1-10-05-002L VDSL/VDSL2 Terminal Equipment 1.82.1 14.8.1 Background Longitudinal output voltage (LOV) limits complement PSD limits by restricting the amplitude of common mode signals much like the PSD limits restrict the amplitude of the equipment’s differential mode signals. LOV limits are necessary as common mode signals tend to couple more readily than differential mode signals in multi-line, twisted pair cable plant. In other words, LOV limits are necessary to limit crosstalk. LOV limits have been crafted to allow higher levels around the equipment’s operating band. This is necessary as a common mode image of the desired differential mode signal results through imbalance in the line interface, cabling and the measurement circuitry. A tighter limit applies above the equipment’s operating band where the LOV source is usually not associated with any signal intended to be applied to the line. VDSL/VDSL2 over POTS modems must also meet certain LOV limits for voiceband terminal equipment. These measurements can be done by using the procedure set out in subclasses 9.15 and 9.17. 1.82.2 14.8.2 Purpose To verify that the longitudinal output voltage is below the limit. 1.82.3 14.8.3 Equipment (1) Spectrum analyzer SEL#34. (2) LOV test fixture shown in Figure 14.8-1. Note: Refer to subclause 5.5 for equipment details. 1.82.4 14.8.4 Equipment States Subject to Test Transmitting continuously as described in subclause 14.4.2. For VDSL2 modems that support extended upstream operation, each Extended Upstream (EU) mask number must be considered. Page 398 Telecommunications Industry Association TR41.9.1-10-05-002L 1.82.5 14.8.5 Procedure In this section the criteria frequency range has been divided into two segments. The number of segments chosen is dependent upon the capabilities of the test equipment. 1.82.5.1 14.8.5.1 Procedure for Segment 1 11. Condition the EUT to transmit continuously as described in subclause 14.4.2. 12. Connect the EUT to the test circuit of figure 14.8-1. 13. Set the spectrum analyzer as follows: Resolution bandwidth: 3 kHz or 4 kHz, if supported by spectrum analyzer Video bandwidth: 300 Hz Attenuation or range: Set for minimum without overload Reference level: (-30) dBV dB/div: 10 dB Start frequency: fa Hz (from Table 63 in TIA-968-B) Stop frequency: 2.5 MHz Marker Function: Voltage dBV Limit test: On with limit line programmed with the LOV limit 14. Measure and record the LOV averaging the readings over several sweeps. 15. Repeat steps 1 to 4 for other Profiles. 16. For extended upstream operation, repeat steps 1 to 5 for each supported EU mask (US0). 1.82.5.2 14.8.5.2 Procedure for Segment 2 (1) Condition the EUT to transmit continuously as described in subclause 14.4.2. (2) Connect the EUT to the test circuit of Figure 14.8-1. (3) Set the spectrum analyzer as follows: Page 399 Telecommunications Industry Association TR41.9.1-10-05-002L Resolution bandwidth: 3 kHz or 4 kHz, if supported by spectrum analyzer Video bandwidth: 1 kHz Attenuation or range: Set for minimum without overload Reference level: (-30) dBV dB/div: 10 dB Start frequency: 2.5 MHz Stop frequency: See Table 63 of TIA-968-B Marker Function: Voltage dBV Limit test: On with limit line programmed with the LOV limit 3. Measure and record the LOV averaging the readings over several sweeps. 4. Repeat steps 1 to 4 for other Profiles. 5. For extended upstream operation, repeat steps 1 to 5 for each supported EU mask (US0). Note: A resolution bandwidth (RBW) of 3 kHz is typically used as most spectrum analyzers support this RBW. 1.82.6 14.8.6 Alternative Method None 1.82.7 14.8.7 Suggested Test Data 3. Plot of the LOV with the limit line shown 4. Upstream signals (US0, US1 & US2) that were measured. 5. Line loop lengths that were used to obtain the LOV measurement for the upstream signals. 1.82.8 14.8.8 Comments Care must be taken in the construction of the LOV test fixture. Resistor values must be matched as previously mentioned. Test leads from the fixture to the EUT should be kept as short as Page 400 Telecommunications Industry Association TR41.9.1-10-05-002L possible to minimize RF ingress. The ground connection to the fixture should be of a low inductance, kept short, and connected directly to the chassis ground of the EUT. For EUT’s without an earth ground, a ground plane should be used as discussed in subclause 9.15.8. NOTE - All resistor values are in ohms, and resistors are to be matched to better than 0.1%. Use a spectrum analyzer with a high input (>10 kohm) impedance. Figure 14.8-1 LOV test fixture & connection diagram, VDSL/VDSL2 Page 401 Telecommunications Industry Association Page 402 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L HEARING AID COMPATIBILITY 1.83 Hearing Aid Compatibility – Magnetic Field Intensity 47 CFR, 68.316 1.83.1 Background The United States Congress has legislated that persons using hearing aids with magnetic pickups shall have reasonable access to the National Telephone Network. All telephones imported and manufactured after August 16, 1989 must be hearing aid compatible. Cordless telephones were exempted until August 16, 1991 must be HAC. Mobile phones are exempted, except in business applications. 1.83.2 Purpose To determine the magnetic field characteristics of hearing aid compatible handsets to ensure adequate magnetic coupling. 1.83.3 Equipment 1. Bandpass filter SEL#5. 2. Sinewave frequency generator SEL#27. 3. Hearing aid probe assembly SEL#29. 4. True rms AC voltmeter SEL#40. 5. Zero level encoder/decoder for all interface types under test (e.g. T1, ISDN) SEL #32 Note: Refer to subclause 5.5 for equipment details. 1.83.4 Equipment States Subject To Test Normal off-hook talking condition. 1.83.5 Test procedure Page 403 Telecommunications Industry Association TR41.9.1-10-05-002L 1.83.5.1 Axial Field Intensity and Frequency Response (Reference Figure 1, EIA-504 as contained in 47 CFR, 68.316). 1. Connect the telephone under test as shown in Figure 12-1-1 for analog telephones, Figure 12-1-2 for digital telephones, Figure 12-1-3 for proprietary and special use telephone or Figure 12-1-4 for IP-based telephones. 2. Set the input at 1000 Hz across the 10 ohm resistor of the matching pad to -10 dBV for analog telephones or (-3) dBV for ISDN telephones. For proprietary, special use and IPbased telephones, an appropriate test circuit and test level is to be used that produces the same acoustic level (nominal (+0) dBPa) with the receive volume control set to its nominal gain level. 3. Position the telephone handset receiver and probe coil for a maximum axial reading and record the field intensity with the true rms AC voltmeter or the dynamic signal analyzer. When testing the IP-based telephones (e.g. VoIP telephones), ensure the duration of the test signals are longer than the packet delay (generally ranging from 100 ms to 300 ms) so the true rms AC voltmeter or the dynamic signal analyzer can capture the maximum axial field intensity readings at each of the measurement frequencies. 4. Determine the appropriate graph from the measured axial field intensity (Figure 4A or 4B, EIA-504 as contained in 47 CFR, 68.316). 5. Measure the frequency response and compare the computed value to the appropriate graph. 6. The axial component of the magnetic field directed along the measurement axis and located at the measurement plan, is to be greater than (-22 dB) relative to 1 A/m at 1000 Hz. 7. For receivers with axial field that exceeds (-19) dB relative to 1 amp per meter (A/m), the frequency response of the axial magnetic field intensity over the range of 300 Hz to 3300 Hz is to fall within the acceptable region of 47 CFR, 68.316, Figure 4A. 1.83.5.2 Radial Field Intensity and Frequency Response (Reference Figure 1, EIA-504 as contained in 47 CFR, 68.316). 1. Connect the telephone under test as shown in Figure 12-1-1 for analog telephones, Figure 12-1-2 for digital telephones, Figure 12-1-3 for proprietary & special use telephone or Figure 12-1-4 for IP-based telephones. Page 404 Telecommunications Industry Association TR41.9.1-10-05-002L 2. Set the input at 1000 Hz across the 10 ohm resistor of the matching pad to -10 dBV for analog telephones or (-3) dBV for for ISDN telephones. For proprietary and special use telephones (e.g. IP-based telephones), an appropriate test circuit and test level is to be used that produces the same acoustic level (nominal (+0) dBPa) with the receive volume control set to its nominal gain level . 3. Position the telephone handset receiver and probe coil for a maximum radial reading and record the field intensity with the true rms AC voltmeter or the dynamic signal analyzer. When testing the IP-based telephones (e.g. VoIP telephones), ensure the duration of the test signals are longer than the packet delay (generally ranging from 100 ms to 300 ms) so the true rms AC voltmeter or the dynamic signal analyzer can capture the maximum radial field intensity readings at the four measurement points in 90-degree intervals. 4. Determine the appropriate graph from the measured radial field intensity as directed in paragraph 4.3 of EIA-504 as contained in 47 CFR, 68.316. 5. The radial component of the magnetic field as measured at 4 points 90 degrees apart, and at a distance greater than or equal to 16 mm from the measurement axis is to be greater than -27 dB relative to 1 amp per meter (A/m), for an input of (-10) dBV at 1000 Hz. Reference 47 CFR, 68.316, subclause 5.5. 6. For receivers with axial field that exceeds (-22) dB relative to 1 amp per meter (A/m), the frequency response of the axial magnetic field intensity over the range of 300 Hz to 3300 Hz is to fall within the acceptable region shown below. Reference 47 CFR, 68.316, Figure 4B. 1.83.6 Alternative Methods None suggested. 1.83.7 Suggested Test Data All measurements are relative to 1 Ampere/meter. 1.83.7.1 Axial field intensity and frequency response 1. Input in dBV. Page 405 Telecommunications Industry Association TR41.9.1-10-05-002L 2. Output in dBV. 3. Normalizing factor relative to 1000 Hz. 4. Calculated field intensity in dB relative to 1 Ampere/meter. 5. Frequency. 6. Output in dBV for each frequency. 7. Net change in dBV relative to 1000 Hz for each frequency. 1.83.7.2 Radial field intensity and frequency response 1. Input in dBV. 2. Output in dBV. 3. Measurement angle. 4. Normalizing factor relative to 1000 Hz. 5. Calculated field intensity in dB relative to 1 ampere/meter. 1.83.8 Comments 1. A chart recorder may be used to plot the data. 2. The probe coil output may be amplified, if needed. 3. For telephone sets which provide the ability to adjust the receive amplitude, the EUT can be deemed to be hearing aid compatible if the requirements of this subclause are met at any one of the available volume settings. For proprietary, special use and IP-based telephones, the volume control may be readjusted after the input level necessary to produce 0 dBPa acoustic output has first been established with the volume control gain set to its nominal level. Page 406 Telecommunications Industry Association TR41.9.1-10-05-002L 4. For Helmholz coil, built in accordance with IEEE standard 1027 is required to calibrate the hearing aid probe. The calibration procedure, in clause 5 of IEEE Standard 1027 is recommended. The integrators in subclause 4.2 and subclause 6.5.3 of IEEE Standard 1027 are not used when making the frequency response measurements. The requirements in Figure 4A and Figure 4B of IEEE Standard 1027 include the 6 dB per octave characteristic of the hearing aid probe coil. Any deviation from the 6 dB per octave slope noted during the calibration procedure using the Helmholz coil is to be included in the measurements. The hearing aid voltage at 1000Hz is to be used as the 0 dB level in Figure 4A and 4B. In other words, the frequency response curve passes through the 0 dB, 1000 Hz point of the figures. Page 407 Telecommunications Industry Association Page 408 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1. The measurement axis is to be paralleled to the reference axis but may be displaced from that axis by a maximum of 10 mm. 2. The battery feed circuit replaces the 2.7 km loop of 26 AWG cable. Figure 15.1-1 Setup for testing 47 CFR, 68.316 HAC for Analog Telephone Page 409 Telecommunications Industry Association Page 410 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1. The measurement axis is to be paralleled to the reference axis but may be displaced from that axis by a maximum of 10 mm. 2. The ISDN telephone reference codec replaces the 2.7 km loop of 26 AWG cable. Page 411 Telecommunications Industry Association TR41.9.1-10-05-002L Figure 15.1-2 Setup for testing 47 CFR, 68.316 HAC for ISDN Telephone Page 412 Telecommunications Industry Association Page 413 TR41.9.1-10-05-002L Telecommunications Industry Association Page 414 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1. The measurement axis is to be paralleled to the reference axis but may be displaced from that axis by a maximum of 10 mm. 2. The test signal generator level is to be set to produce (+0) dBPa at the telephone handset receiver with the receive volume control set to its nominal gain level. Figure 15.1-3 Setup for testing 47 CFR, 68.316 HAC for Proprietary & Special use Telephone Page 415 Telecommunications Industry Association Page 416 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1. The measurement axis is to be paralleled to the reference axis but may be displaced from that axis by a maximum of 10 mm. 2. The test signal generator level is to be set to produce (+0) dBPa at the telephone handset receiver with the receive volume control set to its nominal gain level. Figure 15.1-4 Setup for testing 47 CFR, 68.316 HAC for IP-based Telephone Page 417 Telecommunications Industry Association Page 418 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.84 Hearing Aid Compatibility - Volume Control 47 CFR, 68.317 1.84.1 Background The HAC Act required the FCC to establish regulations that would ensure reasonable access to telephone service by persons with hearing disabilities. The FCC requires hearing aid compatible telephones to provide volume control. 1.84.2 Purpose To determine the Receive Objective Loudness Rating (ROLR) of telephone handset or headset to ensure it complies with the upper and lower ROLR limits required by ANSI/TIA-470-A for analog telephones or ANSI/TIA-579 for digital telephones when the receive volume control is at its normal unamplified level and provides 12 dB of gain minimum and up to 18 dB of gain maximum through the receiver of the handset or headset of the telephone when the receive volume control is set to its maximum volume setting. 1.84.3 Equipment 1. Optional 100 Hz Bandpass filter SEL#5. 2. Zero level encoder/decoder for all interface types under test (e.g. T1, ISDN) SEL #32 Note: Refer to subclause 5.5 for equipment details. 3. Test loops or commercially available artifical loop equivalent to 2.7 km and 4.6 km #26 AWG non-loaded cable SEL#50. 4. Artificial ear SEL#51 for testing telephones with handsets that seal on this type of artificial ear. 5. Artificial ear SEL#69 for testing telephones with handsets that do not seal on artificial ear SEL#51. 6. Standard microphone SEL#52. 7. Microphone measuring amplifier SEL#53. Page 419 Telecommunications Industry Association TR41.9.1-10-05-002L 8. 100 Hz to 5000 Hz sinewave frequency generator SEL#54. 9. AC voltmeter with an input impedance greater than 100 kohm for bridging measurements or equal to 900 ohm for terminated measurements SEL#55. Note: Refer to subclause 5.5 for equipment details. 1.84.4 Equipment States Subject To Test Normal off-hook talking condition. 1.84.5 Test procedure 1. Connect the telephone under test as shown in Figure 13.2.1 for analog telephones, Figure 15.2-2 for ISDN telephones, Figure 15.2-3 for proprietary & special use telephone or Figure 15.2-4 for IP-based telephones. 2. Place the handset receiver on artificial ear SEL#51 if a seal can be achieved between the handset surface and the rim of the artificial ear without the use of sealing putty or similar materials. If a seal cannot be achieved on artificial ear SEL#51, place the handset receiver on artificial ear SEL#69 using the low leak condition specified in ANSI/TIA-470.110-C. 3. The ROLR of the telephone under test is to first be determined with the receive volume control at its normal unamplified level. If the manufacturer does not define a "nominal volume level", either by some marking on the phone (e.g., label at a slide switch detent position) or by some explanation in the user manual, the minimum volume control setting is to be used as the normal unamplified level if the phone meets the requirements of ANSI/TIA-470-A for analog telephones and ANSI/TIA-579 for ISDN, proprietary & special use and IP-based telephones. If the telephone at its minimum volume control setting does not meet the required standards, the volume control is to be increased until it does. The least volume control setting that meets the ANSI/TIA-470-A / ANSI/TIA-579 requirements would then be defined as the normal unamplified level. If the manufacturer does identify the "nominal volume level", then that position has to be used as the starting point. 4. The ROLR of the telephone under test is to be determined by first measuring the receive frequency response according to IEEE 269-2002 using the test circuit of Figure 7 for analog telephone or Figure 13 for ISDN, proprietary & special use and IP-based telephone. The ROLR is then calculated from the measured frequency response as specified in IEEE 661-1979 (R1998). The performance of handset receiver is generally independent of the position (vertical, horizontal face up or down) of the handset. If the telephone being measured uses a carbon transmitter and the receiver characteristics Page 420 Telecommunications Industry Association TR41.9.1-10-05-002L depend on the transmitter resistance, the conditioning procedure specified in IEEE 2692002 should be followed. 5. The battery feeding bridge circuit for analog telephone is to be as shown in Figure 1 of IEEE 269 standard. 6. The reference codec, the zero level encoder/decoder and the analog telephone / IP terminal adapter is to be capable of encoding or decoding analog signals with zero loss for the ISDN, proprietary & special use and IP-based telephone under test. 7. The artificial ear is to be the IEC coupler for supra-aural earphones as described in ANSI S3.7, Method for coupler calibration of earphones. The pressure response of the microphone is to be used in determining the sound pressure generated in the coupler by the receiver. 8. A laboratory standard pressure microphone according to ANSI S1.15 is to be used for measuring the sound pressure generated in the artificial ear. The sensitivity of the microphone should be constant over the frequency range of 100 Hz to 5000 Hz. 9. The frequency response characteristics of the microphone amplifier should be constant over the frequency range from 100 Hz to 5000 Hz. The input-output characteristics of this amplifier should be linear for the range of sound pressure levels to be measured. 10. Measurements of ROLR for analog telephone is to be made for loop conditions represented by 0, 2.7 and 4.6 km of 26 AWG non-loaded cables or equivalent. No variation in loop conditions is required for ISDN, proprietary & special use and IP-based telephones since the receive level of ISDN, proprietary & special use and IP-based telephones are independent of loop length. 11. The sinewave frequency generator is to sweep the frequency range logarithmically from 100 to 5000 Hz. The sweep rate is to be such that one complete transverse of the 100 to 5000 Hz band requires approximately 10 seconds. The generator output is to be adjusted to an open circuit voltage of 0.316 volt (i.e. (-10) dB relative to 1 volt) from a 900 ohm source. The electric source and the measurement circuit should have the capability of operating linearly up to a level of approximately 1 volt. When testing the IP-based telephones (e.g. VoIP telephones), because of the packet delay (generally ranging from 100 ms to 300 ms) in the 10/100 base-T Ethernet hub or the IP network, the test signal from the sinewave frequency generator should be synchronized correctly with the tracking optional bandpass filter and its duration should be long enough for the measuring amplifier and the level recorder to capture the maximum readings at each of the measuring frequencies. 12. The AC voltmeter is to have ranges from 0.01 volt to 10 volt (full scale reading), with an input impedance greater than 100 kohm for bridging measurements or equal to 900 ohm for terminated measurements. Page 421 Telecommunications Industry Association TR41.9.1-10-05-002L 13. Determine the ROLR for each of the applicable loop conditions representing 0, 2.7 and 4.6 km of 26 AWG non-loaded cables or equivalent over the frequency range 300 to 3300 Hz according to IEEE 661 standard. The ROLR is to fall between the upper and lower limits as defined in subclause 4.1.2 of ANSI/TIA-470-A for analog telephones or defined in subclause 4.3.2.2 of ANSI/TIA-579 for ISDN, proprietary & special use and IP-based telephones. 14. Adjust the volume control of the telephone under test to its maximum volume setting. Repeat steps (2) through (11), the ROLR is to be increased by at least 12 dB minimum and 18 dB maximum. Verify that the 12 dB of minimum gain is achieved without significant clipping of the test signal. The 18 dB of receive gain may be exceeded provided the amplified receive capability automatically resets to nominal gain when the telephone is caused to pass through a proper on-hook transition in order to minimize the likelihood of damage to individuals with normal hearing. 15. The ROLR value determined for the maximum volume control setting should be subtracted from that determined for the nominal volume control setting to determine compliance with the gain. 16. If the distortion measured in step (13) is significant, and the gain is greater than 12 dB, the volume control of the telephone under test should be adjusted to its lowest setting that gives at least 12 dB of gain relative to the normal unamplified level as determined in step (2), without significant clipping of the test signal. 1.84.6 Alternative Methods Although 47 CFR, 68.317 specifies the receive volume control requirement in terms of ROLR as defined in IEEE 661-1979 (R1998), current industry standards TIA-470.110-C (replaces TIA-470-A) and TIA-810-B (replaces TIA-579) have shifted to measuring receive loudness in terms of Receive Loudness Rating (RLR) as defined by ITU-T Recommendation P.79. Annex G of TIA-470.110-C provides the following relationship between these two loudness rating measures: ROLR (IEEE 661) = RLR (ITU-T P.79) + 51 dB This relationship may be used to determine if RLR values obtained according to the methods in TIA-470.110-C and TIA-810-B comply with Part 68 criteria specified in terms of ROLR. 1.84.7 Suggested Test Data 1. State the type of artificial ear used for the tests. Page 422 Telecommunications Industry Association TR41.9.1-10-05-002L 2. If the test results were determined as ITU-T P.79 RLR values, show those values and the conversion to ROLR values. 3. State whether the telephone with receive volume control complies with each of the conditions specified in 47 CFR, 68.317. 4. State whether the ROLR of the telephone measured at 0, 2.7 and 4.6 km complies with the upper and lower ROLR limits required by of ANSI/TIA-470 for analog telephones or ANIS/TIA-579 for ISDN, proprietary & special use and IP-based telephones when the receive volume control is set to its normal unamplified level. 5. State whether the ROLR of the telephone measured at its maximum receive volume control setting provides 12 dB of minimum gain and up 18 dB of maximum gain. 6. If the telephone measured at its maximum receive volume control setting exceeded the 18 dB of receive gain, state if the amplified receive capability automatically resets to nominal gain when the telephone is caused to pass through a proper on-hook transition. 1.84.8 Comments 1. This requirement applies to telephones with receive volume control. 2. ROLR is a loudness rating value expressed in dB of loss, more positive values of ROLR represent lower receive levels. Page 423 Telecommunications Industry Association TR41.9.1-10-05-002L Figure 15.2-1 Setup for testing 47 CFR, 68.317 HAC volume control for Analog Telephone Page 424 Telecommunications Industry Association Page 425 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L Figure 15.2-2 Setup for testing 47 CFR, 68.317 HAC volume control for ISDN Telephone Page 426 Telecommunications Industry Association Page 427 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L Figure 15.2-3 Setup for testing 47 CFR, 68.317 HAC volume control for Proprietary & Special use Telephone Page 428 Telecommunications Industry Association Page 429 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L Figure 15.2-4 Setup for testing 47 CFR, 68.317 HAC volume control for IP-based Telephone Page 430 Telecommunications Industry Association Page 431 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L MISCELLANEOUS 1.85 Limitations on Automatic Redialing 47 CFR, 68.318(b) 1.85.1 Background It is possible for equipment to dial the same number continuously until there is an answer. Since CO equipment is being utilized during this time, the FCC ruled that the number of automatic redial attempts to the same number be limited to prevent network harm. Repertory dialers that require manual activation for each attempt are not included under this requirement. Emergency alarm dialers and dialers under external computer control are exempt from this requirement. 1.85.2 Purpose To verify the automatic redialing characteristics of the EUT. 1.85.3 Equipment State Subject to Test Automatic redial function. 1.85.4 Equipment 1. Applicable loop simulator SEL#4. 2. Storage oscilloscope SEL#23. 3. Network Tone Generator SEL#68. 1.85.5 Procedure 1. Consult the EUT manual to determine if the equipment has an automatic redial feature. If it does, perform the following sequence of tests. 2. Configure the equipment for automatic redial testing. 1. Connect the EUT to the circuit shown in . 2. Condition the EUT so that it can automatically redial a predetermined number. Page 432 Telecommunications Industry Association TR41.9.1-10-05-002L 3. Set the storage oscilloscope so that it triggers when the EUT goes off-hook and records up to 70 seconds of activity. 3. Conduct testing for the no answer condition. 1. Activate the automatic redial feature of the EUT. 2. Use the network tone generator to apply audible ringing to the EUT when dialing is complete. 3. Using the storage oscilloscope, measure and record the time interval from the end of dialing until the EUT goes back on hook. 4. Remove the audible ringing signal after the EUT goes back on hook and wait for it to make another redial attempt. 5. Each time the EUT makes a subsequent redial attempt, repeat steps (3)(b) and (3)(d). It is not necessary to repeat step (3)(c) for each successive redial attempt. 6. Count and record the number of successive redial attempts. 7. Wait at least 60 minutes after the last apparent redial attempt to see if the EUT makes another redial attempt in this time window. 4. Conduct testing for the busy tone condition by repeating steps (3)(a) through (3)(g) while applying busy tone to the EUT instead of audible ringing. 5. Conduct testing for the reorder tone condition by repeating steps (3)(a) through (3)(g) while applying reorder tone to the EUT instead of audible ringing. 6. For equipment that detects compatible terminal equipment at the called party end (e.g., modems and fax machines), conduct testing for the condition where non-compatible terminal equipment answers. 1. Activate the automatic redial feature of the EUT. 2. Use the network tone generator to apply audible ringing to the EUT when dialing is complete. 3. After two complete audible ringing cycles, replace the network tone generator with a silent 600 ohm termination to simulate non-compatible equipment answering the call. 4. Determine that the EUT goes back on hook. Page 433 Telecommunications Industry Association TR41.9.1-10-05-002L 5. Remove the 600 ohm termination and wait for the EUT to make another redial attempt. 6. Each time the EUT makes a subsequent redial attempt, repeat steps (6)(b) through (6)(e). 7. Count and record the number of successive redial attempts. 7. Configure the equipment for dial delay testing by resetting the storage oscilloscope so that it records up to 700 ms of activity when the EUT goes off hook. 8. Conduct testing for dialing delay. 1. Activate the automatic redial feature of the EUT. 2. For loop start equipment, apply dial tone to the EUT approximately 200 ms after it goes off hook. 3. For ground start equipment, apply CO ground to the tip conductor approximately 200 ms after the EUT goes of hook. 4. Using the storage oscilloscope, measure and record the time from the application of dial tone or CO ground, as appropriate, until the start of dialing. Also measure and record the time from when the EUT goes off hook to the start of dialing. 1.85.6 Alternative Methods None suggested. 1.85.7 Suggested Test Data 1. Number of successive dialing attempts to the same number when audible ringing is received with no answer. 2. Number of successive dialing attempts to the same number when busy tone is received. 3. Number of successive dialing attempts to the same number when reorder tone is received. 4. Number of successive dialing attempts to the same number when the call is answered by non-compatible equipment. 5. Time interval in seconds from the end of dialing until EUT goes back on hook when audible ringing is received with no answer. Page 434 Telecommunications Industry Association TR41.9.1-10-05-002L 6. Time Interval in seconds from application of busy tone until EUT goes back on hook. 7. Time interval in seconds from application of reorder tone until EUT goes back on hook. 8. For loop start EUTs with automatic dial tone detection, time interval in milliseconds from application of dial tone to start of dialing. 9. For ground start EUTs, time interval in milliseconds from the application of CO ground on the tip conductor to the start of dialing. 10. For EUTs without automatic dial tone detection, time interval in milliseconds from when the EUT goes off hook to start of dialing. 1.85.8 Comments 1. The process of conditioning the EUT so that it can automatically redial a predetermined number may involve making a call attempt to that number and receiving no answer. 2. The suggested level for application of dial tone is -16 dBm per frequency. The suggested level for the application of busy tone and reorder tone is -27 dBm per frequency. The suggested level for the application of audible ringing is -22 dBm per frequency. These levels are typical of the levels the EUT will experience in the network. They are 3 dB below the nominal level applied by the CO to account for typical loop losses. 3. Use of pulse dialing mode (if EUT is so equipped) may facilitate measurement of the start and end of dialing. 4. “Emergency alarm dialers” are dialers that are designed to dial out to a predetermined number in the event of a fire, intrusion, medical, equipment failure, or similar emergency. 5. “Dialers under external computer control” means that the dialer and the computer are not the same product (i.e. may be purchased individually). They may be from one or more manufacturers, and are connected via an interface cable or connector. An example of such products is a stand-alone repertory dialer (capable of auto redialing) connected to a desktop PC via a serial interface. “Dialers under external computer control” does not mean things like a PC telephony card with a PSTN interface that provides a complete telephony function, and can do network addressing (e.g. FAX/modem card). Page 435 Telecommunications Industry Association TR41.9.1-10-05-002L 1. Select the appropriate loop simulator for the interface of the EUT. Refer to the figures of clause 1 of TIA968-B. 2. The oscilloscope should provide a balanced input. Figure 16.1 2 Limitations on automatic redialing Page 436 Telecommunications Industry Association Page 437 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.86 Line Seizure by Automatic Telephone Dialing Systems - 47 CFR, 68.318(c) 1.86.1 Background The automatic telephone dialing systems referred to by this subclause are those typically used for sequentially dialing through a list of telephone numbers and providing a recorded message. The requirement that the equipment release the telephone line is to ensure that the called party can gain access to that line in case of emergency. 1.86.2 Purpose To verify that the equipment releases the telephone line within the required time after notification has been transmitted to it indicating that the called party has hung up. 1.86.3 Equipment None suggested. 1.86.4 Equipment States Subject to Test Test any off-hook state. 1.86.5 Procedure None suggested. See comment (1). 1.86.6 Alternative Methods None suggested. Page 438 Telecommunications Industry Association TR41.9.1-10-05-002L 1.86.7 Suggested Test Data Time for EUT to release the line after notification has been transmitted to it indicating that the called party has hung up. 1.86.8 Comments 4. Specifying a clear test method to test this requirement is extremely difficult. This is because the there is a large range of signals that can be transmitted toward the EUT indicating that the called party has hung up. It is recommended that the test facility devise a test method that is appropriate for the EUT so this parameter is measured properly. This test method needs to be properly documented in the test facilities procedures or the test report or both. 5. This requirement is not applicable to EUT that provides a redial function to the same number. Refer to 47 CFR, 68.318(b). Page 439 Telecommunications Industry Association Page 440 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.87 Telephone Facsimile Machines: Identification of the Sender of Messages (FAX branding) – 47 CFR, 68.318(d) 1.87.1 Background In 1992, the FCC issued rules requiring senders of telephone facsimile (FAX) machine messages to identify themselves on all FAX messages, implementing provisions in the Telephone Consumer Protection Act of 1991. In addition, manufacturers are required to ensure that FAX equipment is capable of marking FAX messages with the required identifying information. The intent of these rules is to control telemarketing nuisances such as unsolicited commercial advertisements, automatic message dialers, and junk FAX mail. These rules first appeared as 47 CFR, 68.318(c)(3) of the FCC rules, but were later moved to 47 CFR, 68.318(d). In 1995, the FAX branding requirement was extended to FAX modems. 47 CFR, 68.318(d) requires FAX machines manufactured on or after December 20, 1992, and FAX modems manufactured on or after December 13, 1995, to have the capability to clearly mark or “brand” the following user provided identifying information in a margin at the top or bottom of each transmitted page (e.g., in a “header” or “footer”): - the date and time that the message was sent; - an identification of the business, other entity, or individual sending the message; and, - the telephone number of the sending machine or of such business, other entity, or individual. The FCC requires a statement in the customer instructions that describes this requirement and tells the user how to set up the FAX machine to produce this header or footer. A sample of this statement is shown in TSB-129-A, clause 8.2.13 (see also comment at 16.3.7(1) below). Prior to the privatization of the 47 CFR Part 68 equipment approval process in 2001, the FCC required manufacturers to attest that their FAX machines had the capability of marking each transmitted page with the required information. This method of demonstrating compliance with 47 CFR, 68.318(d) is still acceptable. If compliance with 47 CFR, 68.318(d) is demonstrated by testing, then the method provided in 16.3.3 through 16.3.5 is recommended. Page 441 Telecommunications Industry Association TR41.9.1-10-05-002L 1.87.2 Purpose The purpose of this procedure is to account for the FAX branding capability requirement in 47 CFR, 68.318(d). This can be accomplished by either a manufacturer’s attestation or testing. A sample attestation letter is provided in 16.3.7, comment 2. The recommended test procedure is described in 16.3.3 through 16.3.5. Recommended information to include in the final test report is described in 16.3.6. 1.87.3 Equipment 4. Additional facsimile machine. 5. Network simulator or compatible network connections. 1.87.4 Equipment States Subject to Test Originating a FAX call. 1.87.5 Procedure 6. If a letter attesting conformity with 47 CFR, 68.318(d) is not provided, follow the customer instructions to enter the current time and date, a company or user name, and user telephone number in the FAX EUT. 7. Connect the FAX equipment to the telephone network simulator or compatible network connection and cause the EUT to transmit a multipage (two or more pages) facsimile message to another facsimile machine. 8. Confirm that the required identifying information is printed on each page of the received facsimile message. 1.87.6 Suggested Test Data 4. Include either an attestation letter or a statement that the FAX equipment demonstrated through testing that it was capable of sending the identifying information required by 47 CFR, 68.318(d). 5. Include a copy of the customer instructions explaining how to enter the current time and date, a company or user name, and user telephone number. 6. Include a sample multipage facsimile message showing the required information in a margin at the top or bottom of each page. Page 442 Telecommunications Industry Association TR41.9.1-10-05-002L 1.87.7 Comments 1. TSB-129-A, clause 8.2.13, states that the customer information for facsimile (FAX) equipment must contain the following wording: The Telephone Consumer Protection Act of 1991 makes it unlawful for any person to use a computer, FAX machine, or other electronic device, to send any message unless such message clearly contains in a margin at the top or bottom of each transmitted page or on the first page of the transmission, the date and time it is sent and an identification of the business or other entity, or other individual sending the message and the telephone number of the sending machine or such business, other entity, or individual. (The telephone number provided may not be a 900 number or any other number for which charges exceed local or long distance transmission charges.) In order to program this information into your FAX machine, you should complete the following steps: [Insert here instructions for programming the equipment and the required information or the page where it can be found]. (2) Sample FAX branding attestation letter (on applicant’s letterhead): To whom it may concern: [Insert name of applicant] attests that this approved facsimile equipment is capable of marking the user provided identifying information required by 47 C.F.R. 68.318(d) in a margin at the top or bottom of each transmitted page. Signed: [Signature of responsible party] Date: [Insert date] Name: [Print name of responsible party] Address: [Insert address of responsible party] (3) Manufacturers are advised to put the setup instructions in an easily accessible location and to make it easy for their customers to comply with this requirement. Page 443 Telecommunications Industry Association Page 444 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.88 Equal Access to Common Carriers - 47 CFR, 68.318(e) 1.88.1 Background As specified in 47 CFR, 68.318(e) any equipment or software manufactured or imported on or after April 17, 1992, and installed by any aggregator shall be technologically capable of providing consumers with access to interstate providers of operator services through the use of equal access codes. 1.88.2 Purpose To verify that the equipment provides the capability to access to interstate providers of operator services through the use of equal access codes. 1.88.3 Equipment None suggested. 1.88.4 Equipment States Subject to Test None suggested. 1.88.5 Procedure 9. Examine the customer instructions for the EUT or software in question and determine if it has the capability of providing consumers with access to interstate providers of operator services through the use of equal access codes. 10. 1.88.6 Alternative Methods None suggested. Page 445 Telecommunications Industry Association TR41.9.1-10-05-002L 1.88.7 Suggested Test Data 7. State whether EUT is capable of providing consumers with access to inter-state providers of operator services through the use of equal access codes. 8. 1.88.8 Comments 2. Due to huge diversity of different manufacturer’s implementation of this capability in their equipment or software, it is extremely difficult to provide a single evaluation method to address all situations. It is recommended that the test facility devise a technique that is appropriate for the EUT so this parameter is evaluated properly. This technique needs to be properly documented in the test facilities procedures or the test report or both. Page 446 Telecommunications Industry Association Page 447 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L APPENDIX A, TEMPLATES for DIGITAL PULSES 1. Templates for Subrate and PSDS Digital Pulses Figure A1-1 through Figure A1-12 provide drawings of the templates for the subrate digital pulse shape limitations. Figures A1-13 and A1-14 provide drawings of the templates for the PSDS digital pulse shape limitations. These drawings include the specified amplitudes, pulse widths, attenuations and filtering. In each case the 10% tolerance specified in TIA-968-B, subclause 4.5.8.1.6 is included in the figure. Pulse shapes may be obtained which do not fall within these limits. In shapes which do not fall within these limits, further comparison to the actual criteria contained in TIA-968-B, subclause 4.5.8.1.6 may be necessary in order to determine compliance to these requirements. Page 448 Telecommunications Industry Association Page 449 TR41.9.1-10-05-002L Telecommunications Industry Association Figure A1-1. Subrate, Pulse Template, 2.4 kilobits per second (kb/s) Page 450 TR41.9.1-10-05-002L Telecommunications Industry Association Page 451 TR41.9.1-10-05-002L Telecommunications Industry Association Figure A1-2. Subrate, Pulse Template, 3.2 kilobits per second (kb/s) Page 452 TR41.9.1-10-05-002L Telecommunications Industry Association Page 453 TR41.9.1-10-05-002L Telecommunications Industry Association Figure A1-3. Subrate, Pulse Template, 4.8 kilobits per second (kb/s) Page 454 TR41.9.1-10-05-002L Telecommunications Industry Association Page 455 TR41.9.1-10-05-002L Telecommunications Industry Association Figure A1-4. Subrate, Pulse Template, 6.4 kilobits per second (kb/s) Page 456 TR41.9.1-10-05-002L Telecommunications Industry Association Page 457 TR41.9.1-10-05-002L Telecommunications Industry Association Figure A1-5. Subrate, Pulse Template, 9.6 kilobits per second (kb/s) Page 458 TR41.9.1-10-05-002L Telecommunications Industry Association Page 459 TR41.9.1-10-05-002L Telecommunications Industry Association Figure A1-6. Subrate, Pulse Template, 12.8 kilobits per second (kb/s) Figure A1-7. Subrate, Pulse Template, 19.2 kilobits per second (kb/s) Figure A1-8. Subrate, Pulse Template, 25.6 kilobits per second (kb/s) Page 460 TR41.9.1-10-05-002L Telecommunications Industry Association Page 461 TR41.9.1-10-05-002L Telecommunications Industry Association Figure A1-9. Subrate, Pulse Template, 38.4 kilobits per second (kb/s) Page 462 TR41.9.1-10-05-002L Telecommunications Industry Association Page 463 TR41.9.1-10-05-002L Telecommunications Industry Association Figure A1-10. Subrate, Pulse Template, 51.2 kilobits per second (kb/s) Figure A1-11. Subrate, Pulse Template, 56.0 kilobits per second (kb/s) Page 464 TR41.9.1-10-05-002L Telecommunications Industry Association Page 465 TR41.9.1-10-05-002L Telecommunications Industry Association Figure A1-12. Subrate, Pulse Template, 72.0 kilobits per second (kb/s) Page 466 TR41.9.1-10-05-002L Telecommunications Industry Association Page 467 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L Figure A1-13. PSDS Type II Pulse Template, 144 kilobits per second (kb/s) Page 468 Telecommunications Industry Association Page 469 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L Figure A1-14. PSDS Type Iii Pulse Template, 160 kilobits per second (kb/s) Page 470 Telecommunications Industry Association TR41.9.1-10-05-002L 1. Templates for ISDN PRA and 1.544 Mb/s Digital Pulses Figures A2-1 and A2-2 show examples of possible templates as derived from the limits given in ANSI/TIA-968-A, subclause 4.5.8.2.2. Pulse shapes may be obtained which do not fall within these limits. In shapes which do not fall within these limits, further comparison to the actual criteria contained in ANSI/TIA-968-A subclause 4.5.8.2.2 may be necessary in order to determine compliance to these requirements. The template for the Option A output pulse is shown in ANSI/TIA-968-A, Figure 4.6. The template for the Option B output pulse was obtained by passing the pulse defined for Option A through the following transfer function: where: n0 = 1.6049x106 n1 = 7.9861x10-1 n2 = 9.2404x10-8 d0 = 2.1612x106 d1 = 1.7223 d2 = 4.575x10-7 d3 = 3.8307x10-14 s = j2f f = frequency (Hz) The template for pulse Option C was obtained by passing the wave form obtained for pulse Option B through the same transfer function. Page 471 Telecommunications Industry Association Page 472 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L Figure A2-1. 1.544 megabits per second (Mbps), Pulse Template, Option B Page 473 Telecommunications Industry Association Page 474 TR41.9.1-10-05-002L Telecommunications Industry Association Page 475 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L Figure A2-2. 1.544 megabits per second (Mbps), Pulse Template, Option C Page 476 Telecommunications Industry Association Page 477 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L APPENDIX B, EXAMPLE CALCULATIONS OF WAVEFORM ENERGY LEVELS where: x = Number of time intervals tn = Time of "nth" interval in seconds Vn = Voltage for time interval n R = Terminating resistance To calculate the energy in the waveform shown in Figure B1-1: 1. Divide the duration (T) into x number of time intervals (tn). The greater the number of intervals, the more accurate the results. In the example calculation, 16 time intervals were used. The intervals do not have to be equal. However, intervals of equal width allow simplification of the calculation. 2. From the graph of the waveform, determine the voltage level for each interval. 3. Calculate the energy level using the equation. If t was selected so that the intervals are of equal width, the equation becomes: where: x = Number of time intervals t = Time interval in seconds Vn = Voltage for time interval n R = Terminating resistance E(j) = 0.26 joules Figure B1-1. Calculation of Energy Levels Page 478 Telecommunications Industry Association TR41.9.1-10-05-002L Annex C, Alternate Transverse Balance, DS1 and xDSL EUT 1.89 C.2 Purpose and scope The purpose of this section is to determine transverse balance of DS1 and xDSL EUT, by using a ratio of currents. This annex is limited to DS1 and all xDSL equipment with 100 ohm impedance. 1.90 C.3 Equipment 6. A precision 50 ohm to 100 ohm BALUN with greater than 60dB of longitudinal balance with respect to the center tap on the 100 ohm side (similar to North Hills 0301BB) SEL#59. 7. Two of the same model precision wound toroidal current monitors (similar to Pearson 4100) SEL#72. 8. Spectrum analyzer SEL#57. 1.91 C.5 Procedure 1. Assemble the circuit shown in figure C-1 and connect the equipment to the circuit as shown. (4) After the test fixture is calibrated as described above, set switch S2 to position C and measure the transverse balance of the EUT. The pass/fail limits in dB for transverse balance versus frequency using the ratio of currents method are the same as the limits specified in ANSI/TIA-968-B for the ratio of voltages method of measurement. However, as is true of any alternative method of test the burden of proof of correlation between the standard and alternative method lies upon the user of the alternative methodology. Measured values must be reduced by 6dB to obtain the actual transverse balance of the EUT. Page 479 Telecommunications Industry Association TR41.9.1-10-05-002L Figure C-1: Test Fixture To Measure Transverse Balance Using A Ratio Of Currents Page 480 Telecommunications Industry Association Page 481 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L Appendix D, Test Procedures for Passive Splitter Filters and Passive Micro-Filters 1.92 D.1 Background ADSL systems are designed to share the same loop facility with voice services. When voice and data services share the same phone line, filters are usually needed on the customer premises. Low-Pass Filters (LPFs) block high-frequency transients and impedance effects that result from voice service operation (e.g., ringing transients, ring trip transients, and off-hook transients and impedance changes) from reaching the ADSL modem. The LPF also blocks high frequency ADSL signals from reaching voice terminal equipment which may be affected by such frequencies. The LPF function can be implemented either internally or externally to the ADSL modem. When the LPF function is performed externally, the LPF is generally a stand-alone device. There are many stand-alone LPFs on the market and they come in different shapes and sizes. Most, but not all, have "ADSL" printed somewhere on the device. There are two basic types of stand-alone LPFs – the splitter filter and the micro-filter. The splitter filter is a centrally located in-line LPF and micro-filters are distributed in-line LPFs. 1.93 D.2 Example of Splitter Filter For the purposes of this evaluation, a splitter filter is a stand-alone, single line, three port, wall mounted device that is usually installed on the customer’s side of the Network Interface (NI) near the point where the phone line comes into the customer premises. The Line Port of the splitter filter connects to the phone line and the Splitter internally divides the phone line into separate voice and data lines which appear at the Phone and ADSL Ports respectively. Splitter filters used with ADSL modems always contain a low-pass filter (LPF) for the voice frequency port and may or may not contain a high-pass filter (HPF) for the data port. If the associated ADSL modem contains a HPF, then the splitter filter does not need to provide a HPF on the data port. If the ADSL modem does not contain a HPF, then use an external splitter filter with a HPF for the data port. The splitter filters considered in this evaluation are wall mounted, have a metallic cover, and are not powered from an external source and do not contain active electronic components but rather consist entirely of passive components. Such Splitters do not transmit internally generated signals or provide port to port amplification of signals passing through the device. The performance standard for splitter filters used in North America is ITU-T G.992.1 Annex E.2. 1 2 Page 482 Telecommunications Industry Association TR41.9.1-10-05-002L 1.94 D.3 Example of Micro-Filter For the purposes of this evaluation, a micro-filter is a stand-alone, single line, two port, non-wall mounted device installed on the customer’s side of the NI at each jack where voice terminal equipment is connected to the phone line. The Line Port of the micro-filter connects to the phone line and the Phone Port connects to the customer’s voice equipment (e.g., telephone, FAX machine, etc.). The micro-filters considered in this evaluation are encased in non-conductive plastic and have no exposed conductive surfaces. In addition, micro-filters are not powered from an external source and do not contain active electronic components but rather consist entirely of passive components. The performance standard for micro-filters used in North America is T1.421. 1.95 D.4 Applicable ANSI/TIA-968-A Technical Criteria from TSB-31-C Test Matrix Splitter filters and micro-filters are intended to be connected to lines with an ordinary (analog, loop start) voice service and an ADSL-based data service. Based on the test matrix associated with this document, the technical criteria with an “X” in the loop start and ADSL columns of Table D-1 are applicable to terminal equipment connecting to loop start interfaces and ADSL interfaces. The “Test Splitter Filter” and “Test Micro-Filter” columns of Table D-1 indicate whether or not a specific test needs to be performed on the splitter filters and micro-filters described above. Rationale is given in each instance where compliance may not need to be verified through testing. Page 483 Telecommunications Industry Association TR41.9.1-10-05-002L Table D-1 Technical Criteria for Splitter Filter and Micro-Filter Examples ANSI/TIA-968-A Technical Criteria Applicable to Loop Start and ADSL Interfaces Technical Criteria Loop Start ADSL Splitter Filter MicroFilter 4.2.1 Mechanical Shock X X No (1) Yes (1) 4.2.2 Surge A Metallic and Longitudinal X X Yes Yes 4.2.3 Surge B Metallic and Longitudinal X X Yes Yes 4.2.4 Power Line Surge X X No (2) No (2) 4.3 Leakage Current X X Yes (3) No (3) 4.4.1 Hazardous Voltage – General X X Yes Yes 4.4.2 Hazardous Voltage - Separation of Leads X X No (4) No (4) 4.4.5.2 Intentional Protective Paths to Ground X X No (5) No (5) 4.5.2.1 Signal Limits - Voiceband - Not Network Control Signals X No (6) No (6) 4.5.2.2 Signal Power Limits - Voiceband - Network Control Signals X No (6) No (6) 4.5.2.3.2 Signal Limits - Through Transmission Equipment – Data X No (6) No (6) 4.5.2.4 Signal Power Limits - Voiceband Signal Power – Data X No (6) No (6) 4.5.2.5.1 Through Transmission - Port To Port Amplification X Yes (7) Yes (7) 4.5.2.5.1(7) Signal Power Limits - Through Transmission - SF cutoff X No (6) No (6) 4.5.2.5.2 Signal Limits - Through Transmission - SF/Guard Band X Yes Yes 4.5.3.1 Signal Limits – 3995-4005 Hz - Not Network Control Signals X No (6) No (6) 4.5.3.2 Through Transmission Loss - 3995-4005 Hz vs 600-4000 Hz X Yes Yes 4.5.4 Signal Limits – Non LADC Longitudinal Voltage 0.1 - 4 kHz X No (6) No (6) Page 484 X Telecommunications Industry Association TR41.9.1-10-05-002L 4.5.5.1 Signal Limits – Non LADC Metallic Voltage 4 kHz-30 MHz X 4.5.5.2 Signal Limit - Non LADC Longitudinal Voltage 4kHz-6MHz X No (6) No (6) X No (6) No (6) 4.5.9.1.1 Signal Power Limits – ADSL – Total Signal Power X No (6) No (6) 4.5.9.1.2 Signal Power Limits – ADSL – PSD X No (6) No (6) 4.5.9.3 Signal Power Limits – ADSL - Longitudinal Output Voltage X No (6) No (6) X Yes (8) Yes (8) X Yes Yes 4.6.2 Transverse Balance – Analog X 4.6.3 Transverse Balance – ADSL 4.7.2.1 On-Hook Impedance Limits - DC resistance X X Yes Yes 4.7.2.3 On-Hook Impedance Limits - DC current during ringing X X Yes Yes 4.7.2.4 On-Hook Impedance Limits - AC impedance during ringing X X Yes Yes 4.7.4 On-Hook Impedance Limits - REN calculation X X Yes Yes 4.7.8 On-Hook Impedance Limits - Transitioning to off-hook state X No (9) No (9) 4.8.1.1 Billing Protection - Call Duration for Data Equipment X No (6) No (6) 4.8.1.2 Billing Protection - Call Duration for Data Applications X No (6) No (6) 4.8.2 Billing Protection - On-Hook Signal Power X No (6) No (6) 4.8.3 Billing Protection - Off-Hook Loop Current X No No 4.8.4.1 Billing Protection - Signaling Interference Analog X No (6) No (6) 6. Connectors X Yes (10) Yes (10) 1. No, if the device is wall mounted, otherwise Yes. 2. It is assumed that the device has no power cord. 3. Yes, if the device has any of the test point combinations defined in ANSI/TIA-968-A, clause 4.3, otherwise No, Page 485 Telecommunications Industry Association TR41.9.1-10-05-002L 4. It is assumed that the device has no power leads or leads to non-approved equipment. 5. No, if the device has no intentional protective path to ground, otherwise Yes. 6. No, if the device does not connect to an external source of power, consists entirely of passive components, and cannot internally generate signals or amplify through signals, otherwise Yes. 7. The RTE to PSTN requirement only. 8. On-hook requirement only if the device has no off-hook state. 9. No, if the device has no off-hook state, otherwise Yes. 10. Yes, if the device has a plug or jack or both, otherwise No. Page 486 Telecommunications Industry Association Page 487 TR41.9.1-10-05-002L Telecommunications Industry Association Page 488 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.96 D.5 Test Methods for Splitter Filters (1) Mechanical Shock Simulation – Mechanical shock simulation is not applicable if the device is wall mounted. If mechanical shock simulation is applicable to the particular splitter filter under test, the simulation methods would be no different than the methods used for other terminal equipment. (2) Surge Simulations – The power line surge simulation is not applicable if the device has no power cord. The methods for performing surge simulations for splitter filters are no different than the methods used for other terminal equipment. Surges should be applied with the splitter filter in all states that can affect compliance with the requirements of ANSI/TIA-968-A with equipment leads not being surged terminated in a manner that occurs in normal use. (3) Leakage Current Limitations – Leakage current limitations are applicable if the splitter filter has conductive surfaces or any of the other test point combinations specified in ANSI/TIA968-A. The methods for testing leakage current are no different than the methods used for other terminal equipment. (4) Hazardous Voltage Limitations – The methods for checking for hazardous voltage on the tip and ring leads of the splitter filter’s line port are no different than the methods used for other terminal equipment. (5) Signal Power Limitations – Except as explained below for the applicable Through Transmission tests, signal power tests are not applicable when the splitter filter consists entirely of passive components and does not internally generate signals or amplify through signals. For the applicable Through Transmission tests, the test signal should be applied to the Phone Port and the measurement made at the Line Port. Repeat the test by transmitting the test signal into the ADSL Port and measuring the signal at the Line Port. (6) Transverse Balance – The transverse balance requirements of ANSI/TIA-968-A, sections 4.6.2 and 4.6.3, should be tested on the Line Port in the following states as listed in Table D-2 below: Page 489 Telecommunications Industry Association TR41.9.1-10-05-002L Table D-2 Splitter Filters Transverse Balance Test States Port Under Test ADSL Port Phone (Voice) Port Line Unterminated Unterminated Line Unterminated Terminated - Off-Hook Line Unterminated Terminated - On-Hook Line Terminated Unterminated Line Terminated Terminated - Off-Hook Line Terminated Terminated - On-Hook The following terminations should be used: Phone on-hook termination = Figure 4.13 of ANSI/TIA-968-A-4 with R1 adjusted per the note in Figure 4.13. Phone off-hook termination = Use Figure 4.9 of ANSI/TIA-968-A with R1 adjusted per the note in Figure 4.9. ADSL termination = Figure 4.14 of ANSI/TIA-968-A-4. (7) On-Hook Impedance Limits – The following tests should be performed with both the Phone and ADSL Ports unterminated: On-hook DC resistance requirement of ANSI/TIA-968-A, clause 4.7.2.1; DC current during ringing requirement of ANSI/TIA-968-A, clause 4.7.2.3; AC impedance during ringing requirement of ANSI/TIA-968-A, clause 4.7.2.4; and, REN calculation requirement of ANSI/TIA-968-A, clause 4.7.4. Note: The test methods for connectors associated with splitter filters are no different than the methods used for other terminal equipment. Page 490 Telecommunications Industry Association Page 491 TR41.9.1-10-05-002L Telecommunications Industry Association TR41.9.1-10-05-002L 1.97 D.6 Test Methods for Micro-Filters (1) Mechanical Shock Simulation – Mechanical shock simulation is applicable if the device is not wall mounted. The methods for mechanical shock simulation are no different than the methods used for other terminal equipment. (2) Surges – The power line surge simulation is not applicable if the device has no power cord. The methods for performing surge simulations are no different than the methods used for other terminal equipment. Surges should be applied with the micro-filter in all states that can affect compliance with the requirements of TIA-986-A with equipment leads not being surged terminated in a manner that occurs in normal use. (3) Leakage Current Limitations – This test is not applicable if the device has no conductive surfaces nor any of the other test point combinations specified in ANSI/TIA-968-A. If the test is applicable, the methods are no different than the methods used for other terminal equipment. (4) Hazardous Voltage Limitations – The methods for checking for hazardous voltage on the tip and ring leads of the micro-filter’s line port are no different than the methods used for other terminal equipment. (5) Signal Power Limitations – Except for applicable Through Transmission tests, signal power tests are not applicable when the micro-filter consists entirely of passive components and does not internally generate signals or amplify through signals. For applicable Through Transmission tests, the test signal should be applied to the Phone Port and the measurement made at the Line Port. (6) Transverse Balance – The transverse balance requirements of ANSI/TIA-968-A, sections 4.6.2 and 4.6.3, should be tested in the following states as listed in Table D-3 below: Table D-3 Micro-Filters Transverse Balance Test States Port Under Test Port Termination Line Port Phone Unterminated Line Port Phone Terminated - Off-Hook Line Port Phone Terminated - On-Hook Phone Port Line Unterminated Phone Port Line Terminated - Off-Hook Page 492 Telecommunications Industry Association Phone Port TR41.9.1-10-05-002L Line Terminated - On-Hook The same phone on-hook and off-hook terminations defined for splitter filter transverse balance testing should be used for micro-filter transverse balance testing. The ADSL modem termination defined for splitter filter transverse balance testing is not used for micro-filter transverse balance testing. (7) On-Hook Impedance Limits – The following tests should be performed with the Phone Port unterminated: On-hook DC resistance requirement of ANSI/TIA-968-A, clause 4.7.2.1; DC current during ringing requirement of ANSI/TIA-968-A, clause 4.7.2.3; AC impedance during ringing requirement of ANSI/TIA-968-A, clause 4.7.2.4; and, REN calculation requirement of ANSI/TIA-968-A, clause 4.7.4. Note: The test methods for connectors associated with micro-filter are no different than the methods used for other terminal equipment. Page 493 Telecommunications Industry Association TR41.9.1-10-05-002L DRAFT Revision & Change Log Rev 0.1 (April 14, 2010): This initial draft was created from a file provided by Clift Marten, former editor of TSB31-C. The document was believed to be the final ballot version dated April 2006. This is the starting point for revision effort TSB 31-D. DRAFT Revision & Change Log was added Headers changed to PN-3-3602-RV4 to become TIA/TSB-31-C Rev 0.2 (April 19, 2010): Inserted Matrix of TIA-986-A to TIA-968-B under section 5.5 and changed the references in the section titles to TIA-968-B as described in Matrix. Rev 0.3 (April 27, 2010): Modified Forward and Scope to call out TIA-968-B instead of TIA-968-A and its addends. Rev 0.4 (April 30, 2010): Inserted contributions from February, 2010 meeting. TR41.9-10-02-010-Alternate Transverse Balance_MR1 TR41.9-10-02-011-Suggested Equipment List_MR1 TR41.9-10-02-012-VDSL2 Test Procedures_MR1 Page 494
