Next Generation Air/Ground CommunicationsNext Generation Air/Ground Communications

(NEXCOM) Program(NEXCOM) ProgramPresented to

Airborne Internet Collaboration GroupReston VA

April 17, 2003

Dieter ThigpenIntegrated Product Team for Communications

Federal Aviation Administration

2

What is NEXCOM? Next Generation Air/Ground Communications

• FAA’s program to modernize and improve VHF air/ground communications in the National Airspace System (NAS)– Fundamental change from analog to digital technology

• VHF Digital Link Mode 3 (VDL-3)– Time Division Multiple Access Technology– Maintains current 25 kHz frequency separation, but – Provides 4 non-interfering channels on 1 frequency– All channels suitable for voice or data

– Operates in the 118-137 MHz band allocated for Air Traffic use

• Impacts both ground and airborne elements of the NAS

3

National Airspace System (NAS)Transition to Digital Communications

Dem/ValDem/Val

• Analog Voice, 25 KHz

• Full Operational Evaluation& Exercise of Digital Voiceand Datalink (VDL-3)

Next 5 years

AnalogVoice

5-10 years

• Maintain Terminal Analog Voice

• Implement VDL-3Digital Voice

Enroute High Airspace

National Airspace

RCAGARTCC

VDL-3Link

10-15 years

• Expand EnrouteDigital Voice (VDL-3)

• Initiate TerminalDigital Voice (VDL-3)

• Increase Datalink Capacity& Capability (VDL-3)

TerminalAirspace

15-20 years

• Expand Digital Voice (VDL-3) to all domains

• Expand Datalink Capacityin all domainsand all applications(VDL-3)

AFSS

4

• VHF and UHF ATC bands• Approximately 10,000 VHF

assignments• Approximately 50,000 VHF &

UHF TX, RX & TCVRs• Dedicated networks for each

operational environment• Limited restoral capabilities• Limited remote maintenance

capability

NAS Air/Ground Communications Infrastructure Components

61 AFSSs, 14 FSSs Automated Flight Service Stations, Flight Service Stations

21 ARTCCs & 3 CERAPsAir Route Traffic Control Center,Combined Center Radar Approach Control

793 RCAGsRemote Communications Air/Ground

1854 RCOsRemote

Communications Outlet

175 TRACONsTerminal Radar Approach Control

1422 RTRsRemote Transmitter Receiver

346AirportTowers

720 BUECsBack up Emergency

Communications

5

National Airspace System Environments

Typical System Handoff:

Preflight into Departure: Tower hands off to TRACON; TRACON hands off to En Route System.

Departure, En Route, Descent into Approach: ARTCCs, AFSSs and Remote Comm Facilities (RCAG, RCO, RTR, BUEC) hand off to each other and eventually back to a TRACON. That Approach TRACON will handoff to the destination Tower.

Terminal Environment Terminal EnvironmentEn Route

Terminal: D

epartu

re

Terminal: Destination

RCFs

RCFs

RCFs

RCFs

RCFs

RCFs

AFSS

As long as aircraft is below 10,000 ft

From when aircraft returns to 12,000 ft

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NEXCOM Acquisition Program Elements

Multimode Digital Radio

Analog & digital

Ground System

System Demo Program

NEXCOM architecture & commercial avionics

Digital capability forvoice and data

VHF T/R

RIUGNI

Avionics

Analog & digital

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NEXCOMAcquisition Program Elements

Multimode Digital Radio (MDR)• Compatible with today’s radios

– Double Side Band-AM 25 kHz

– 8.33 kHz

– VDL Mode3

– Interfaces to the future NEXCOM Ground System

• Replaces current NAS ITT & Motorola CM200 radios– Initial use is replacement of aging radio infrastructure

• Contract Awarded July 01 to ITT; Base Year with 9 Options• Operational testing at Key Site complete Fall 02

• Further operational testing at second key site Fall 03

• Radio deployment begins early 2004

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NEXCOM Acquisition Program Elements

Ground System Segment

• Components• Radio Interface Unit (RIU)

– Provides capability for digital communications

• Ground Network Interface (GNI)

– Provides connectivity for voice switches

• Two-Phase Development• Rapid Preliminary Development Effort (RPDE) (Mar 02-Dec 04)

– ITT and Harris Teams selected as vendors in Feb 03

• Full Scale Development Program (FSDP) (Jan 05-Dec 07)– Only RPDE vendors compete

VHF T/RRadio

InterfaceUnit

GroundNetworkInterface

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NEXCOM Acquisition Program Elements

Avionics • Components

• Multimode VHF radio• Radio Control Panel• Communications Management Unit (optional)

• FAA/Manufacturer Agreements signed Dec 01• Rockwell Collins, Honeywell – airlines• Avidyne – general aviation• Pending agreement – business jets

• Agreements include cost sharing and payable events

• Pre-production models to be used in System Demo II (Fall 03)

• Goal is certified avionics commercially available in 2005

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NEXCOM Acquisition Program Elements

System Demonstration Program• Series of three demonstrations

– Fall 02, Fall 03 at FAA Tech Center• Demo 1 was very successful• Participants included NATCA controllers and pilots

– Fall 04 at an operational site

• Objectives– Fall 02: VDL Mode 3 Technology viability– Fall 03: NEXCOM Architecture feasibility

• Vendors provide pre-production avionics– Fall 04: Operational suitability

• Commercial avionics

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NEXCOM Schedule

2001 2003 2004 200920052002 2006 2007 2008

System DemoProgram

10/03SystemDemo II

10/04OperationalDemo

10/02SystemDemo I

MultimodeDigitalRadio 7/01

Contract Award

MDR deployment

3/04Notice ofAvailability TSO

9/03AEECApprovedChar.

Avionics8/04

CertifiedAircraft

10/01MOPS

10/02Strawman

CharacteristicsComplete

01/10Operational

6/05-12/09 Aircraft equip

10/01Sys Reqs

Doc

2/03RPDEContract Awards

1/05Full Scale Dev Contract Award

Validation & Inter-Operability Tests

10/07Keysite

12/01GIAs

04/04Begin

Deployment

8-11/02Ops

Testing

GroundSystem

07-12 Implementation

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Technical Slides

Back Up Slides

13

Spectrum Requirements GrowthC

irc

uit

s (

10

00

s)

5

10

15

20

25

1998 2003 2008 2013 2018 2023 2028Year

Increasing Cost and Difficulty of Provisioning New Circuits

Historically, circuit growth Averages 4% per year.

Increasing cost/difficulty ofplacing new circuitsreduces growth rate

Reduced growth rate implies less-efficient NAS.

Growth in A/G Circuit Demand

23 spectrum recovery initiatives

(ASR)

• Growth in channel demand is based on # of flights, not passenger growth

• Channel demand must meet peak flight period demand, not average demand

Unsatisfied DemandReduces NAS Efficiency

# DeployedA/G Circuits

14

Typical TDMA Frame FormatConfigurations

* Slot devoted entirely as Management Subchannel

A DCB

TDMA Frame 120 ms

4V

3TDis

cret

e A

ddre

ssed

Voi

cean

d D

ata

Voi

ce O

nly

Voice VoiceVoiceVoice

3V1D DataVoiceVoiceVoice

2V2D Voice DataDataVoice

*Voice/Data

Voice/Data

Voice/Data

User GroupsSupported

Services toEach Group

4

N/A

2

3Dedicated Voice

w/Shared Data Slot

Demand AssignedVoice and Data

(Trunked)

Dedicated Voiceand Data

Dedicated VoiceOnly

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VDL-3 Channel Structure

= 120 ms “TDMA frame” is the fundamental timing framework= Each slot contains two independent “bursts” = M bursts are used for channel management; while V/D

bursts are used for voice or data transfers

4-slot Configurations

Time slotA

Time slotB

Time slotC

Time slotD

30 ms slot

ManagementSubchannel

Voice/DataSubchannel

TDMA Frame (120 ms)

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• Frequency range 118–137 MHz• Channelization 25 kHz centers• Channel structure Same frequency for uplink and downlink• Radio range* 200 nmi for 4-slot configurations

600 nmi for 3-slot configurations• Symbol rate 10.5 kbaud (3 bits /symbol) • Modulation Differential 8-ary Phase Shift Keying

(D8PSK) • Access technique Time Division Multiple Access (TDMA)• Voice encoding 4.8 kbps (Normal Voice)

4.0 kbps encoding (Truncated Voice) • Data Functionally simultaneous with voice

* Range takes into consideration of propagation delay and timing errors of the aircraft radios only

NEXCOMVDL 3 CHARACTERISTICS

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Summary

• The NEXCOM system is currently under development and projected Initial Operational Capability by end of 2009.

• NEXCOM is implementing a Command and Control Link (CCL). (There is no requirement to deliver wide bandwidth applications)

• Internet Protocol (IP) would require international (International Civil Aviation Organization) and national (Radio Technical Commission for Aeronautics Inc.) certification for use as an Air Traffic Control CCL.

• VDL Mode 3 has operated with Internet Protocol (IPv4) using the CLNP (ConnectionLess Network Protocol) interface at the WJHTC. FAA has not validated IPv4.

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Acronyms

AEEC Airlines Electronics Engineering Committee NOA Notice of AvailabilityARTCC Air Route Traffic Control Center NPRM Notice of Proposed RulemakingASP Acquisition Strategy Paper OEP Operational Evolution PlanBUEC Back Up Emergency Communications OTA Other Transaction AuthorityCA Contract Award RCAG Remote Communications Air/GroundCERAP Combined Center Radar Approach Control RCO Remote Communications OutletCSMA Carrier Sense Multiple Access RTR Remote Transmitter ReceiverDLAP Data Link Application Processor RPDE Rapid Preliminary Development EffortFAT Factory Acceptance Test RIU Radio Interface UnitFSDP Full Scale Development Program SAT Site Acceptance TestGNI Ground Network Interface SC Special CommitteeICAO International Civil Aviation Organization SIR Screening Information RequestIOC Initial Operational Capability SRD System Requirements DocumentIPP Integrated Program Plan STC Supplemental Type CertificateISD In-Service Decision TDMA Time Division Multiple AccessJRC Joint Resource Council TSO Technical Standard OrderMDR Multi-Mode Digital Radio TSOA Technical Standard Order AuthorizationMOPS Minimum Operational Performance Standards VDL VHF Digital Link