FCS Technology Assessment Team: Technology Assessment Phase II P34 Overview

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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

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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)
1000s kbps
Broadband
100s kbps
Wideband
10s kbps
Narrow band
Channel Widths
25 MHz
6.25 kHz
25 kHz
200 kHz
50 kHz
APCO P25 Phase 1, 2 Tetra Release
1 TETRAPOL IDRA iDEN EDACS
Chart courtesy of EADS Defense and Communications
Systems, as provided in correspondence between
ITT and EADS
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Evolution of Public Safety Radio Standards
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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

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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)

• 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
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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
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Inbound Random Access Frame Structure
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P34 Air Interface Interactions
IP Bearer Service Access Point
IP Bearer Service Access Point
IPv4 IPv6
IPv4 IPv6
Layer 3
Subnetwork Dependent Convergence Protocol (SNDCP)
Layer 3
Subnetwork Dependent Convergence Protocol (SNDCP)
MM
PDS
MM
PDS
Logical Link Control (LLC)
Logical Link Control (LLC)
Radio Link Adaptation (RLA)
Radio Link Adaptation (RLA)
Layer 2
Layer 2
Media Access Control (MAC)
Media Access Control (MAC)
PHY
PHY
Layer 1
Layer 1
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SNDCP Context Activation Sequence Diagram
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UP Acknowledged Data Transmission Sequence
Diagram
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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