Assessment of Radio Spectrum Depletion in the U.S. in the VHF Comm Band

1. Assessment of Radio Spectrum Depletion in the U.S. in the VHF Comm Band Don Willis Federal Aviation Administration Washington, DC March 30, 2004 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. Analysis –Con’t(Without Implementation of 23 Initiatives)

6. 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. 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. Analysis - Con’t(With Optimization) • En-route: To support one additional high sector requirement for ZNY, the following re-tunes are required • Terminal: To support one additional departure/arrival requirement at JFK, the following re-tunes 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. Until 2015, We Can Support: • En-route • Without Optimization • Up to 3 new super-high, high, or low enroute sectors for the Eastern half of the US • Up to 30 new super-high, high, or low enroute sectors in the U.S. if all commercial and business aircraft are equipped with 760 channel radios • With Optimization • May be able to satisfy about 3-5 additional requirements in the Eastern half of the US with some difficulty and cost • 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 • About 2-3 additional requirements per OEP airport may be satisfied

11. To Survive 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 • Air Traffic complete Phase II of the AT frequency audit

12. BackgroundInformation

13. VHF 23 Initiatives • Developed by a group of experts to obtain additional spectrum resources or to make available current spectrum resources through various proposals • Regulatory • Technical • Administrative

14. 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

15. 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

16. 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