Download TR41.9-16-02-012-Signal Power test procedures for FAST DSL

Telecommunications Industry Association
TR41.9-16-02-XXX
Document Cover Sheet
Project Number
TIA-PN-31-D-4
Document Title
Signal Power Limitations test procedures for FAST DSL
Source
Cisco Systems
Contact
Tim Lawler
170 West Tasman Dr.
San Jose, CA 95134
Distribution
TR-41.9
Intended Purpose
of Document
(Select one)
X
Phone: (408) 527-0681
Fax: (408) 853-3288
Email: [email protected]
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 3.3.2.2 through 3.3.2.4 inclusive of the TIA Engineering Committee Operating Procedures dated
May 2014, all of which provisions are hereby incorporated by reference.
Abstract
This contribution is a proposal for adding Signal Power Limitations test procedures for FAST DSL to TSB31-D-4.
V2.1 – 20141205
Telecommunications Industry Association
TR41.9-16-02-XXX
Add the following items to sub-clause 5.5, Suggested Equipment List (SEL):
(80)
RF power meter: minimum sensitivity of 0.1 V and a minimum input impedance of
10 kohm over the frequency range from 1 MHz to 300 MHz minimum.
(81)
Spectrum analyzer: input impedance 50 ohms, frequency range from 30 MHz to at
least 300 MHz, sensitivity of -130 dBm/Hz or better, resolution < 1 Hz, absolute
amplitude accuracy +1.5 dB or better.
(82)
100:50 ohm balun transformer: frequency range 30 MHz to 300 MHz minimum.
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Telecommunications Industry Association
9.41
556B
TR41.9-16-02-XXX
Signal Power Limitations, FAST Terminal Equipment TIA-968-B-3, 5.3.10.1
9.41.1 Background
The aggregate signal or total power of the FAST 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.
557B
9.41.2
Purpose
The purpose of this test is to verify that the signal power level transmitted to the network
does not exceed the requirement.
558B
9.41.3
Equipment
(1)
RF power meter SEL#80.
(2)
100 ohm, 1 %, non-inductive resistor.
Note: Refer to subclause 5.5 for equipment details.
559B
9.41.4
Equipment States Subject to Test
The equipment under test should be transmitting continuously at its highest obtainable
signal power.
560B
9.41.5
Procedure
(1)
Condition the EUT to transmit its upstream signals at the highest power level.
(2)
Connect the EUT to the test circuit of Figure 9.41-1.
(3)
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.
561B
9.41.6 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.
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Telecommunications Industry Association
562B
9.41.7
TR41.9-16-02-XXX
Suggested Test Data
(1)
Signal power level.
(2)
Loop characteristics or test mode via software used to obtain the total power
measurement.
563B
9.41.8
Comments
(1)
If the RF power meter has a 50 ohm input impedance then a 50 to 100 ohm BALUN
may be necessary.
(2)
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)
FIGURE 9.41-1 AVERAGE SIGNAL POWER
Note: If the RF power meter has 50 ohms input impedance, a 50 to 100 ohm BALUN is
needed and the 100 ohm resistor would be removed.
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