A I R T R A F F I C O R G A N I Z A T I O N FCS Technology Assessment Team: Technology Assessment Phase II – P34 Overview Presented at ICAO ACP WGC Meeting,

A I R T R A F F I C O R G A N I Z A T I O N

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

2

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

3

Public Safety Radio Standards Segmentation

Bit Rate

Channel

Widths

1000’s kbps Broadband

25 MHz

10’s kbps Narrow band

6.25 kHz 25 kHz 200 kHz

100’s kbps Wideband

50 kHz

Chart courtesy of EADS Defense and Communications Systems, as provided in correspondence between ITT and EADS

APCO P25 Phase 1, 2Tetra Release 1

TETRAPOLIDRAiDEN

EDACS

APCO 34Tetra Release 2 (TAPS,

TEDS)

Project Mesa

4

Evolution of Public Safety Radio Standards

Pre-standard Analog, 25

kHz FM

European Standards Evolution

Pre-standard Analog FM Systems

NarrowbandTetra Release I25 kHz 4-slot

TDMAUHF Band

WidebandTetra Release IITAPS – E-GPRS Overlay Network

WidebandTetra Release IITEDS – MCM,

TDMA, Adaptive Modulation, 150 kHz

UHF Band

SolutionSpace*

US Standards EvolutionAPCO Project 16 Study

WidebandAPCO Project 34OFDM 150 kHz

Channels700 MHz Band

Solution Space*

APCO Project 25 Phase I

12.5 kHz DigitalVHF and UHF

Bands

APCO Project 25 Phase II

12.5 kHz TDMAVHF and UHF

Bands

Narrowband

*Solution space - The set of technologies for constructing a public safety network.

BroadbandProject Mesa

50 MHz channel at 4.9 GHz

(Joint ETSI and EIA/TIA Standard)

5

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

6

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

7

P34 Overview (3)

• 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

Source: “Spectrum Considerations for Public Safety in the United States”, Tewfik L. Doumi, IEEE Communications Magazine, January 2006

Source: “Spectrum Considerations for Public Safety in the United States”, Tewfik L. Doumi, IEEE Communications Magazine, January 2006

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Wideband (P34) Data Standards Status

PHYTIA-902.BAAB

CHCTIA-902.BAAD

MAC/RLATIA-902.BAAC

LLCTIA-902.BAAE

SAMModulation

PDSTIA-902.BAEB

TMSTIA-902.AAAB

MMTIA-902.

BAAF

Legend

Not Started

Drafting

Balloting

Published

TPRTIA-902.CBAB

MOMTIA-902.CBAA

IOTAPerformance

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)

TPRTIA-902.CAAB

MOMTIA-902.CAAA

SAMPerformance

PHYTIA-902.BBAB

CHCTIA-902.BBAD

IOTAModulation

700 MHz Interoperability Mode700 MHz General Use Mode

700 MHz General Use Mode

Chart courtesy of EADS Defense and Communications Systems, as provided in correspondence between ITT and EADS

Required forInteroperability

Provides AdditionalCapacity

Relevant P34 Standards are

mature

PHYTIA-902.BAAB

CHCTIA-902.BAAD

MAC/RLATIA-902.BAAC

LLCTIA-902.BAAE

SAMModulation

PDSTIA-902.BAEB

TMSTIA-902.AAAB

MMTIA-902.

BAAF

Legend

Not Started

Drafting

Balloting

Published

TPRTIA-902.CBAB

MOMTIA-902.CBAA

IOTAPerformance

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)

TPRTIA-902.CAAB

MOMTIA-902.CAAA

SAMPerformance

PHYTIA-902.BBAB

CHCTIA-902.BBAD

IOTAModulation

700 MHz Interoperability Mode700 MHz General Use Mode

700 MHz General Use Mode

Chart courtesy of EADS Defense and Communications Systems, as provided in correspondence between ITT and EADS

Required forInteroperability

Provides AdditionalCapacity

Relevant P34 Standards are

mature

9

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

10

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

12

Inbound Random Access Frame Structure

13

PDP context activation, LLC UP setup, data transfer

CP functions: acknowledgement, retransmission, optional enhanced error detectionUP 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

IPv4IPv6

Logical Link Control(LLC)

MMPDS

Subnetwork Dependent Convergence Protocol

(SNDCP)

PHY

Media Access Control(MAC)

Radio Link Adaptation(RLA)

Layer 1

Layer 2

Layer 3

Layer 1

Layer 2

Layer 3

IP Bearer Service Access Point

IPv4IPv6

Logical Link Control(LLC)

MMPDS

Subnetwork Dependent Convergence Protocol

(SNDCP)

PHY

Media Access Control(MAC)

Radio Link Adaptation(RLA)

IP Bearer Service Access Point

P34 Air Interface Interactions

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SNDCP Context Activation Sequence Diagram

service user SNDCP LLC CP MAC service userSNDCPLLC CPMAC

service user SNDCP LLC CP MAC service userSNDCPLLC CPMAC

IP Datagram

SN_Activate_Req

Activate_Wait timerLLC_Connect_Req RSC_Req on RACH

RSC_RES(Grant)

MABK on RACH slotsMAC_Connect_Ind

LLC_Connect_Res(Accept)MAD_RES(SAC) MSBK on SSCH

T1Retry

MAC_Connect_CON(Accept)

MSBK_RSC_REQ

MRC RSC_RES (grant)

Resource Management

LLC_Signal_Req

MAC_Signal_Confirm

OB_MHBKT1Retry

MSBK_TNP_SIG(SN_Activate_Req) MAC_Signal_Ind

(llc control pdu)

LLC_Signal_Req

MSBK_TNP_SIG(llc control pdu)MAC_Signal_Ind

(CP_RES pdu)MAC_Signal_Con

LLC_Signal_Ind

SN_Activate_Acpt_Res

LLC_Signal_Con

Ack TimerLink Management

MRC FNE

KEY

MABK - MAC Address Access BlockMAD_RES - MAC Address ResponseMSBK - MAC Signaling BlockRSC_REQ – Resource RequestRSC_RES - Resource ResponseOB_MHBK – Out Bound Message Header BlockMAC_Signal_Ind – MAC / RLA Service PrimitiveTNP_SIG – Transport Signal

service user SNDCP LLC CP MAC service userSNDCPLLC CPMAC

service user SNDCP LLC CP MAC service userSNDCPLLC CPMAC

IP Datagram

SN_Activate_Req

Activate_Wait timerLLC_Connect_Req RSC_Req on RACH

RSC_RES(Grant)

MABK on RACH slotsMAC_Connect_Ind

LLC_Connect_Res(Accept)MAD_RES(SAC) MSBK on SSCH

T1Retry

MAC_Connect_CON(Accept)

MSBK_RSC_REQ

MRC RSC_RES (grant)

Resource Management

LLC_Signal_Req

MAC_Signal_Confirm

OB_MHBKT1Retry

MSBK_TNP_SIG(SN_Activate_Req) MAC_Signal_Ind

(llc control pdu)

LLC_Signal_Req

MSBK_TNP_SIG(llc control pdu)MAC_Signal_Ind

(CP_RES pdu)MAC_Signal_Con

LLC_Signal_Ind

SN_Activate_Acpt_Res

LLC_Signal_Con

Ack TimerLink Management

MRC FNE

KEY

MABK - MAC Address Access BlockMAD_RES - MAC Address ResponseMSBK - MAC Signaling BlockRSC_REQ – Resource RequestRSC_RES - Resource ResponseOB_MHBK – Out Bound Message Header BlockMAC_Signal_Ind – MAC / RLA Service PrimitiveTNP_SIG – Transport Signal

15

UP Acknowledged Data Transmission Sequence Diagram

service user SNDCP LLC UP MAC service userSNDCPLLC UPMAC

service user SNDCP LLC CP MAC service userSNDCPLLC CPMAC

MSBK_RSC_REQ

MRC RSC_RES (grant)

Resource Management

Open

LLC_ Data_Req

LLC_Data_Confirm

OB_MHBK

T1Retry

MDBKs(UP data) MAC_Data_Ind

UP_Response(LLC Ack PDU)MSBK

MAC_Signal_Ind(LLC Ack PDU)

Schedule PDCH Tx

IP Datagram

SN_Data_Req

Segment Data

Ack Timer

LLC_Data_IndSN_Data PDU

Assemble Data

MAC_Data_Confirm

Standby/Ready

Ready Timer

MRC FNE

KEY

SN_Data_Req – IP DatagramLLC_Data_Req – Interlayer primitiveMSBK - MAC Signaling BlockRSC_REQ – Resource RequestRSC_RES - Resource ResponseOB_MHBK – Out Bound Message Header BlockMDBKS – MAC Data BlocksMAC_Data_Confirm – Interlayer primitiveMAC_Data_Ind – Interlayer primitiveLLC_Data_Ind – Interlayer primitiveSN_Data_PDU – Payload DataLLC Ack – Acknowledgement FramesMSBK – MAC Signaling Block

service user SNDCP LLC UP MAC service userSNDCPLLC UPMAC

service user SNDCP LLC CP MAC service userSNDCPLLC CPMAC

MSBK_RSC_REQ

MRC RSC_RES (grant)

Resource Management

Open

LLC_ Data_Req

LLC_Data_Confirm

OB_MHBK

T1Retry

MDBKs(UP data) MAC_Data_Ind

UP_Response(LLC Ack PDU)MSBK

MAC_Signal_Ind(LLC Ack PDU)

Schedule PDCH Tx

IP Datagram

SN_Data_Req

Segment Data

Ack Timer

LLC_Data_IndSN_Data PDU

Assemble Data

MAC_Data_Confirm

Standby/Ready

Ready Timer

MRC FNE

KEY

SN_Data_Req – IP DatagramLLC_Data_Req – Interlayer primitiveMSBK - MAC Signaling BlockRSC_REQ – Resource RequestRSC_RES - Resource ResponseOB_MHBK – Out Bound Message Header BlockMDBKS – MAC Data BlocksMAC_Data_Confirm – Interlayer primitiveMAC_Data_Ind – Interlayer primitiveLLC_Data_Ind – Interlayer primitiveSN_Data_PDU – Payload DataLLC Ack – Acknowledgement FramesMSBK – MAC Signaling Block

16

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