Assessment of Radio Spectrum Depletion on ATC Voice Communications

1. Assessment of Radio Spectrum Depletion onATC Voice Communications Steve Zaidman, AAF-1 George Sakai, ASR-1 Federal Aviation Administration Washington, DC September 16, 2003 There are no benefits to compromising safety…only dire consequences

2. Objective To determine the availability of frequencies to meet the FAA’s spectrum requirements until 2015

3. Methodology • How many new en-route sectors can be accommodated in today’s environment at all 20 centers… • Without implementation of 23 Initiatives? • With the implementation of some Initiatives? • With optimization? • How many new terminal requirements can be supported at 4 major OEP airports… • Without implementation of 23 Initiatives? • With the implementation of some Initiatives? • With optimization?

4. Spectrum Depletion Analysis(Without Implementation of 23 Initiatives)

5. Spectrum Depletion Analysis – Con’t(Without Implementation of 23 Initiatives)

6. Spectrum Depletion Analysis – Con’t(With Implementation of Some Initiatives) Notes: *--- indicates that the frequency can be assigned if inter-modulation problems are resolved Values in ( ) indicate the total number of potential assignments, including *---

7. Spectrum Depletion Analysis - Con’t(With Implementation of Some Initiatives) Notes: *--- indicates that the frequency can be assigned if inter-modulation problems are resolved Values in ( ) indicate the total number of potential assignments, including *---

8. Spectrum Depletion Analysis - Con’t(With Optimization) • En-route: To support 1 additional high sector requirement for ZNY, the following re-tunes to the existing environment are required • Terminal: To support 1 additional departure/arrival requirement at JFK, the following re-tunes to the existing environment are required

9. Spectrum Depletion Analysis Summary • Without Optimization of Existing Environment • En-route: No channels available for Super High, High, and Low sectors in ZAU, ZDC, ZID, ZNY, ZOB, and ZTL • Terminal: No channels available for JFK, ATL, ORD, and DFW • With Optimization of Existing Environment • Provides the potential ability to satisfy additional requirements • Examples • En-route: 6 existing facilities need to be re-tuned to accommodate 1 new high enroute sector in ZNY • Terminal: 5 existing facilities need to be re-tuned to accommodate 1 new departure/arrival requirement at JFK

10. What We Can Support until 2015 • En-route • Without Optimization • Accommodate up to 3 new Super High, High, or Low en-route sector requirements for the Eastern-half of the US (provided that 2 flight-inspection channels are moved above 136 MHz and a frequency “swap” with AFTRCC is accomplished) • If all commercial and business aircraft are equipped with 760 channel radios, up to 30 additional new Super High, High, or Low en-route sector requirements in the US can be accommodated • With Optimization • May be able to satisfy additional requirements (approx. 3-5) in the Eastern-half of the US, however, it would be difficult and costly • Terminal • Without Optimization • No frequencies currently available for the 4 OEP airports used in the study. Other OEP airports will likely have similar or limited number of available channels. • With Optimization • Additional requirements (2-3 per OEP airport in congested areas) may be satisfied

11. What Needs to be Done if NEXCOM IOCis Delayed Until 2015 • Restrict Air-Traffic operational requirements (e.g. National Airspace Re-Design) • Obtain funding to complete the following: • Procure maintenance radios for AF technicians (frees-up 2 flight inspection frequencies below 136 MHz) • Move users above 136 MHz (Treasury, Customs, AFTRCC, etc.) • Procure equipment for increased co-site interference mitigation • “Optimize” the VHF spectrum in congested areas • Procure equipment and resources for more selective keying (frees up approx. 113 frequency assignments) • Procure equipment and resources for 6 kHz “off-set” carrier frequency use • Require all commercial and business aircraft to upgrade to 760 channel radios (This will require rule-making) • Air-Traffic needs to complete Phase II of the AT frequency audit

12. BackgroundInformation

13. Problem: Limited VHF Resource FAA  DoD  Other Federal  Non-Federal 76-88 MHz TVChannels 5,6 108-137 MHz VHF Nav and Comm 88-108MHz FM Broadcast 54-72 MHz TV Channels 2,3,4 COMM. NAV 117.975 MHz-137.0 MHz 108-117.975 MHz VOR / ILS ATC ATC ATC AOC Other AOC 124 MHz 129 MHz 137.0 MHz 118 MHz 122 MHz 132 MHz 108 MHz 136.5 MHz 136.0MHz ATC Voice ATC Voice AOC Voice ACARS ATC Voice

14. Current VHF Spectrum Utilization Channel Usage Air Traffic Services Usage Others 10% EnRoute 25.3% Terminal 40.2% ATS 70.5% AOC 19.5% ATIS/AWOS/ASOS 15.3% Search & Rescue 6.7% (121.5 MHz, 123.1 MHz) All Others 12.5% Total Number of Channels Available (118-137 MHz): 760 Total Channels Available for ATC: 535* * Number of channels include those channels made available from implemented VHF initiatives to date.

15. U. S. Growth of ATC Frequency Assignments Average increase in number of channel assignments per year = 307

16. This Leads to VHF Congestion • Increasingly difficult to satisfy ATC requirements in some parts of the country • New York • Washington D.C. • Chicago • Cleveland • Atlanta • New spectrum requirements continue to grow -- additional sectors, runways, FIS, AWOS/ASOS, etc.

18. VHF 23 Initiatives • Developed to obtain additional spectrum resources or to make available current spectrum resources through various proposals • Regulatory • Technical • Administrative

19. VHF 23 Initiatives (Regulatory Proposals) • Review FCC frequency utilization plan and investigate the use of UNICOM and other FCC aeronautical frequencies for ATC • Investigate the possibility of using FSS channels for ATC, including the frequencies 123.6 through 123.65 MHz • Review fire-fighting frequency assignment policy • Review policy for AWOS and ASOS frequency use • Review air show frequency policy

20. VHF 23 Initiatives (Technical Proposals) • Investigate use of part of 121.5 MHz guard band for ATC channels • Investigate use of the band 136-137 MHz • Investigate use of existing communications air/ground radios on VOR frequencies for AWOS and ASOS (broadcast only) • Investigate offset operation (+/- 6 to 10 kHz off-tuned from the primary frequency) for high altitude use • Investigate lowering ground control transmit antennas • Investigate advantages of optimizing equipment location • Investigate co-site mitigation techniques, for example, new technologies such as active interference cancellers, and testing to determine use of lower transmit powers

21. VHF 23 Initiatives (Administrative Proposals) • Conduct Air Traffic audit of ATC frequencies • Investigate alternate frequencies for flight check • Investigate use of law enforcement channels • Review operational coverage requirements for communications facilities • Review ground control sub-band • Review use of two VHF DoD common channels • Modify FAA data base to accept additional data which would allow tighter “packing” of frequencies • Improve coordination with ARINC on their VHF frequency usage • Investigate increased use of select keying and voting systems • Re-use ground control frequencies at high altitude (“vertical separation”) • Review use of high-gain (directional) antennas