1. Next Generation Air/Ground Communications (NEXCOM) Program Presented to Airborne Internet Collaboration Group Reston VA April 17, 2003 Dieter Thigpen Integrated Product Team for Communications Federal Aviation Administration

2. 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. 3 National Airspace System (NAS) Transition to Digital Communications Dem/Val Analog Voice, 25 KHz Full Operational Evaluation & Exercise of Digital Voice and Datalink (VDL-3) Next 5 years Analog Voice 5-10 years Maintain Terminal Analog Voice Implement VDL-3 Digital Voice Enroute High Airspace National Airspace RCAG ARTCC VDL-3 Link 10-15 years Expand Enroute Digital Voice (VDL-3) Initiate Terminal Digital Voice (VDL-3) Increase Datalink Capacity & Capability (VDL-3) Terminal Airspace 15-20 years Expand Digital Voice (VDL-3) to all domains Expand Datalink Capacity in all domains and all applications (VDL-3) AFSS

4. 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 CERAPs Air Route Traffic Control Center, Combined Center Radar Approach Control 793 RCAGs Remote Communications Air/Ground 1854 RCOs Remote Communicatio ns Outlet 175 TRACONs Terminal Radar Approach Control 1422 RTRs Remote Transmitter Receiver 346 Airport Towers 720 BUECs Back up Emergency Communications

5. 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 En Route Terminal: Departure Terminal: Destination RCFs AFSS As long as aircraft is below 10,000 ft From when aircraft returns to 12,000 ft

6. 6 NEXCOM Acquisition Program Elements Multimode Digital Radio Analog & digital Ground System System Demo Program NEXCOM architecture & commercial avionics Digital capability for voice and data VHF T/R RIU GNI Avionics Analog & digital

7. 7 NEXCOM Acquisition 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

8. 8 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/R Radio Interface Unit Ground Network Interface

9. 9 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

10. 10 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

11. 11 NEXCOM Schedule 200120032004200920052002200620072008 System Demo Program 10/03 System Demo II 10/04 Operational Demo 10/02 System Demo I Multimode Digital Radio 7/01 Contract Award MDR deployment 3/04 Notice of Availability TSO 9/03 AEEC Approved Char. Avionics 8/04 Certified Aircraft 10/01 MOPS 10/02 Strawman Characteristics Complete 01/10 Operational 6/05-12/09 Aircraft equip 10/01 Sys Reqs Doc 2/03 RPDE Contract Awards 1/05 Full Scale Dev Contract Award Validation & Inter-Operability Tests 10/07 Keysite 12/01 GIAs 04/04 Begin Deployment 8-11/02 Ops Testing Ground System 07-12 Implementation

12. 12 Technical Slides Back Up Slides

13. 13 Spectrum Requirements Growth Circuits (1000s) 5 10 15 20 25 1998200320082013201820232028 Year Increasing Cost and Difficulty of Provisioning New Circuits Historically, circuit growth Averages 4% per year. Increasing cost/difficulty of placing new circuits reduces 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 Demand Reduces NAS Efficiency # Deployed A/G Circuits

14. 14 Typical TDMA Frame Format Configurations

15. 15 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

16. 16 Frequency range118–137 MHz Channelization25 kHz centers Channel structureSame frequency for uplink and downlink Radio range*200 nmi for 4-slot configurations 600 nmi for 3-slot configurations Symbol rate10.5 kbaud (3 bits /symbol) Modulation Differential 8-ary Phase Shift Keying (D8PSK) Access techniqueTime Division Multiple Access (TDMA) Voice encoding4.8 kbps (Normal Voice) 4.0 kbps encoding (Truncated Voice) DataFunctionally simultaneous with voice * Range takes into consideration of propagation delay and timing errors of the aircraft radios only NEXCOM VDL 3 CHARACTERISTICS

17. 17 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.

18. 18 Acronyms