Download ACP-WGC11-WP31-P34_Overview

AIR TRAFFIC ORGANIZATION
FCS Technology Assessment Team:
Technology Assessment Phase II –
P34 Overview
Presented at ICAO ACP WGC Meeting,
Brussels, Belgium
September 21, 2006
Prepared by:
ITT/Glen Dyer
NASA/James Budinger
Public Safety Radio Systems
•
Standardized systems with open interfaces
– APCO Standards
• Developed by TR-8 Private Radio Technical Standards Committee, under sponsorship of
the TIA in accord with a memorandum of understanding between TIA and
APCO/NASTD/FED (Association of Public Safely Communications Officials/National
Association of State Telecommunications Directors/Federal Government).
– TETRA Standards
• Produced by the Project Terrestrial Trunked Radio (TETRA) Technical Body of the
European Telecommunications Standards Institute (ETSI)
– TETRAPOL
• Development of the publicly available specifications for TETRAPOL has been carried out
by the manufacturers of the TETRAPOL Forum and the TETRAPOL Users’ Club
– IDRA
• Standardized by the Association of Radio Industries and Businesses (ARIB). The first
version of Japan's digital dispatch standard, called RCR STD-32, was completed in
March 1993. An updated version of this standard which did not alter the basic RF
characteristics of the standard, but which did add substantial networking capability to the
system, was approved in November 1995, and is referred to as RCR STD-32A.
•
Commercial spectrally efficient land mobile radio systems
– Integrated Digital Enhanced Network (iDEN™) (referred to internationally as
DIMRS) – Proprietary Motorola narrow-band TDMA voice and data system
– EDACS (Enhanced Digital Access Communications System) – Proprietary
Ericsson trunked narrow-band fail-soft system for critical communications
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Public Safety Radio Standards
Segmentation
Project Mesa
Bit Rate
APCO 34
Tetra Release 2 (TAPS,
TEDS)
1000’s kbps
Broadband
100’s kbps
10’s kbps
Wideband
Narrow band
Channel
Widths
APCO P25 Phase 1, 2
Tetra Release 1
TETRAPOL
IDRA
iDEN
EDACS
6.25 kHz
25 kHz
50 kHz
200 kHz
25 MHz
Chart courtesy of EADS Defense and Communications Systems, as provided in correspondence between ITT and EADS
3
Evolution of Public Safety Radio
Standards
US Standards Evolution
APCO Project
16 Study
Narrowband
Pre-standard
Analog, 25
kHz FM
APCO Project
25 Phase I
12.5 kHz Digital
VHF and UHF
Bands
APCO Project
25 Phase II 12.5
kHz TDMA
VHF and UHF
Bands
European Standards Evolution
Pre-standard
Analog FM
Systems
Narrowband
Tetra Release I
25 kHz 4-slot
TDMA
UHF Band
*Solution space - The set of technologies for constructing a
public safety network.
Wideband
APCO Project 34
OFDM 150 kHz
Channels
700 MHz Band
Solution
Space*
Broadband
Project Mesa
50 MHz channel at
4.9 GHz
(Joint ETSI and
EIA/TIA Standard)
Wideband
Tetra Release II
TAPS – E-GPRS
Overlay Network
Solution
Space*
Wideband
Tetra Release II
TEDS – MCM,
TDMA, Adaptive
Modulation, 150 kHz
UHF Band
4
P34 Overview
•
APCO Project 34 is a EIA/TIA standardized system for provision of packet
data services in an interoperable dispatch oriented topology for public safety
service providers
– Standards available here: http://global.ihs.com
– Example standard description
• TIA-902.BAAB - Complete Document Revision: A Chg: Date: 09/23/03 WIDEBAND
AIR INTERFACE SCALABLE ADAPTIVE MODULATION (SAM) PHYSICALLAYER
SPECIFICATION - PUBLIC SAFETY WIDEBAND DATA STANDARDS PROJECT DIGITAL RADIO TECHNICAL STANDARDS
•
Project 34 concept is a government/commercial partnership
– Provides universal access to all subscribers
– Carefully controlled and managed network
•
Was developed to address “issues that restrict the use of commercial
services for mission critical public safety wireless applications”
–
–
–
–
Priority access and system restoration
Reliability
Ubiquitous coverage
Security
5
P34 Overview (2)
•
•
A P34 network (called a “Wideband
System”) can interoperate with other
P34 networks (the ISSI standardized
interface) with end-systems (Ew
interface) and with mobile users
over the air interface (Uw)
The air interface has defined modes
between mobiles (MR to MR);
between mobiles and fixed
infrastructure (MR to FNE) and
repeated modes for extending range
to distant stations
– Mobile Radios can serve as
repeaters to extend range from FNE
to distant Mobile Radios
•
The protocol stack is layered, and
assumes a point of attachment to an
IP network
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P34 Overview (3)
Source: “Spectrum
Considerations for
Public Safety in the
United States”, Tewfik L.
Doumi, IEEE
Communications
Magazine, January 2006
• P34 systems (shown as TIA-902 in the figure) are slated to be
deployed using Frequency Division Duplexing with
– Forward Link (Fixed Network Equipment, FNE, to Mobile Radios, MRC)
between 767 and 773 MHz as shown in the figure
– Reverse Link (MRC to FNE) between 797 and 803 MHz
• The band could be cleared in some areas by December 31, 2006
– Provided at least 85% of households have digital capable TV sets
• Most likely date is (hard requirement) January 2009
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Wideband (P34) Data Standards
Status
Relevant P34
Standards are
mature
TMS
Not Started
TIA-902.AAAB
Drafting
PDS
MM
Balloting
TIA-902.
BAEB
TIA-902.
BAAF
Published
Transceiver Methods of Measurement (MOM)
Transceiver Performance Recommendation (TPR)
Text Messaging Specification (TMS)
Packet Data Specification (PDS)
Mobility Management (MM)
Logical Link Control (LLC)
Media Access Control / Radio Link Adaptation (MAC/RLA)
Radio Channel Coding (CHC)
Physical (PHY)
LLC
Legend
TIA-902.BAAE
MAC/RLA
Required for
Interoperability
TIA-902.BAAC
MOM
CHC
CHC
MOM
TIA-902.CBAA
TIA-902.BBAD
TIA-902.BAAD
TIA-902.CAAA
TPR
PHY
PHY
TPR
TIA-902.CBAB
TIA-902.BBAB
TIA-902.BAAB
TIA-902.CAAB
IOTA
IOTA
SAM
Performance
Modulation
Modulation
Provides Additional
Capacity
700 MHz General Use Mode
SAM
Performance
700 MHz Interoperability Mode
700 MHz General Use Mode
Chart courtesy of EADS Defense and Communications Systems, as provided in correspondence between ITT and EADS
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P34 Air Interface (PHY) Description
• There are two air interfaces (PHY) defined
– SAM for interoperability
• Has random access burst structure that incorporates 625 s
propagation guard time (187.5 km) and 208.33 s ramp-down (not
included in guard)
– VDL 3 guard time includes the ramp-down time and is 1.14 ms (334 km)
• Random access burst structure rules could be modified to
significantly increase system range
– IOTA to provide additional data capacity
• Has random access burst structure that incorporates 500 s
propagation guard time (150.0 km) and 500 s ramp-down
• MAC uses timing advance to offset mobile propagation delays
– From the standard: “A timing advance feature managed by the MAC
layer assumes that propagation delays are not seen at the radio receiver
level except for initial random access slot”
• Random access burst structure rules could be modified to
significantly increase system range
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Air Interface Specifics
• Both Air Interfaces use a form of Multi-Carrier Modulation
(Orthogonal Frequency Division Multiplexing, OFDM)
• Frequency Domain Extensibility
– Base channel is 50 kHz, with extensions defined to 100 kHz and
150 kHz
– Each 50 kHz segment is comprised of 8 subcarriers (that map to
defined subchannels)
• Concatenate subchannel sync/pilot/data structure of the 50 kHz slot
two, three times
• Simplifies receiver design
• Completely scalable to much larger bandwidths (if needed)
– Each 50 kHz provides 96 to 288 kbps (modulation adapts with
Eb/No)
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Scaleable Adaptive Modulation
Parameters
Parameter
50 kHz Channel
Configuration
100 kHz Channel
Configuration
150 kHz Channel
Configuration
RF Subchannels
8
16
24
Subchannel Spacing
5.4 kHz
5.4 kHz
5.4 kHz
Symbol Rate
4.8 k
4.8 k
4.8 k
Symbol Filter
Root Raised Cosine
( = 0.2)
Root Raised Cosine
( = 0.2)
Root Raised Cosine
( = 0.2)
Modulation Type 1
QPSK
(2 bits/symbol)
QPSK
(2 bits/symbol)
QPSK
(2 bits/symbol)
Modulation Type 2
16QAM
(4 bits/symbol)
16QAM
(4 bits/symbol)
16QAM
(4 bits/symbol)
Modulation Type 3
64QAM
(6 bits/symbol)
64QAM
(6 bits/symbol)
64QAM
(6 bits/symbol)
Modulation Rate 1
76.8 kbps
153.6 kbps
230.4 kbps
Modulation Rate 2
153.6 kbps
307.2 kbps
460.8 kbps
Modulation Rate 3
230.4 kbps
460.8 kbps
691.2 kbps
Demodulation
Coherent (Pilot Symbol
Assisted)
Coherent (Pilot Symbol
Assisted)
Coherent (Pilot Symbol
Assisted)
TDM Slot Time
10 ms
10 ms
10 ms
Slot Interleave
Variable
Variable
Variable
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Inbound Random Access Frame
Structure
12
P34 Air Interface Interactions
IP Bearer Service Access Point
IP Bearer Service Access Point
IPv4
IPv6
IPv4
IPv6
Layer 3
Layer 3
PDP context activation, LLC UP setup, data transfer
Subnetwork Dependent
Convergence Protocol
(SNDCP)
PDS
MM
Logical Link Control
(LLC)
Layer 2
Radio Link Adaptation
(RLA)
Media Access Control
(MAC)
Layer 1
PHY
Subnetwork Dependent
Convergence Protocol
(SNDCP)
PDS
MM
CP functions: acknowledgement, retransmission, optional
enhanced error detection
UP functions: Segmentation/Reassembly, acknowledgments,
selective retransmission, enhanced error detection, flow
control, windowing, buffering
Dynamic selection of modulation, channel coding, logical
channel multiplexing configuration
Synchronization, scrambling, link management, random
access procedure, MAC address allocation, radio resource
allocation, power control
Logical Link Control
(LLC)
Radio Link Adaptation
(RLA)
Layer 2
Media Access Control
(MAC)
PHY
Layer 1
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SNDCP Context Activation
Sequence Diagram
FNE
MRC
service user
SNDCP
LLC CP
MAC
MAC
LLC CP
SNDCP
IP
Datagram
KEY
SN_Activate_Req
Activate_Wait timer
service user
LLC_Connect_Req
RSC_Req on RACH
RSC_RES(Grant)
Link Management
Ack Timer
MABK on RACH slots
MAC_Connect_Ind
LLC_Connect_Res(Accept)
T1Retry
MAD_RES(SAC)
MSBK on SSCH
MAC_Connect_CON
(Accept)
MABK - MAC Address Access
Block
MAD_RES - MAC Address
Response
MSBK - MAC Signaling Block
RSC_REQ – Resource Request
RSC_RES - Resource Response
OB_MHBK – Out Bound
Message Header Block
MAC_Signal_Ind – MAC / RLA
Service Primitive
TNP_SIG – Transport Signal
LLC_Signal_Req
MSBK_RSC_REQ
Resource Management
MRC RSC_RES (grant)
T1Retry
OB_MHBK
MAC_Signal_Confirm
MSBK_TNP_SIG
(SN_Activate_Req)
MAC_Signal_Ind
(llc control pdu)
LLC_Signal_Ind
SN_Activate_Acpt_Res
LLC_Signal_Req
MAC_Signal_Ind
(CP_RES pdu)
MSBK_TNP_SIG
(llc control pdu)
MAC_Signal_Con
LLC_Signal_Con
service user
SNDCP
LLC CP
MAC
MAC
LLC CP
SNDCP
service user
14
UP Acknowledged Data
Transmission Sequence Diagram
FNE
MRC
service user
SNDCP
LLC UP
MAC
MAC
LLC UP
SNDCP
service user
KEY
SN_Data_Req – IP Datagram
LLC_Data_Req – Interlayer primitive
MSBK - MAC Signaling Block
RSC_REQ – Resource Request
RSC_RES - Resource Response
OB_MHBK – Out Bound Message Header
Block
MDBKS – MAC Data Blocks
MAC_Data_Confirm – Interlayer primitive
MAC_Data_Ind – Interlayer primitive
LLC_Data_Ind – Interlayer primitive
SN_Data_PDU – Payload Data
LLC Ack – Acknowledgement Frames
MSBK – MAC Signaling Block
Standby/Ready
IP
Datagram
SN_Data_Req
Ready Timer
Segment Data
LLC_ Data_Req
MSBK_RSC_REQ
Ack Timer
Resource Management
Schedule
PDCH Tx
MRC RSC_RES (grant)
OB_MHBK
T1Retry
Open
MAC_Data_Confirm
MDBKs
(UP data)
MAC_Data_Ind
Assemble Data
LLC_Data_Ind
SN_Data PDU
UP_Response
(LLC Ack PDU)
MSBK
MAC_Signal_Ind
(LLC Ack PDU)
LLC_Data_Confirm
service user
SNDCP
LLC CP
MAC
MAC
LLC CP
SNDCP
service user
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Overview of P34 Modeling
• P34 Analysis conducted
– OPNET Modeling – the P34 protocol stack was modeled using OPNET
Modeler
• High fidelity simulation of protocol stack provided insight into technology
performance
• Offered load and scenario as specified in COCR for NAS “Super Sector”
– Physical Layer Modeling – P34 physical layer was modeled with high
fidelity by developing a custom C code application
• Provided insight into technology performance in aviation environment
• For performance assessment, C was chosen over SPW and MATLAB
Simulink® due to complexity of P34 pilot structure
– Interference Modeling – a model of the P34 transmitter was developed
using SPW to assess P34 interference to UAT and Mode-S Receivers
• DME receiver modeling was undertaken, but was eventually terminated due to
lack of “as built” algorithm information and insufficient fidelity with predictions
to known results
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