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Agenda Item 1.d.i:Review of the ICAO Position for WRC-07; Agenda Item 1.6; Resolution 414

Status of the VHF initiatives

(Presented by Mike Biggs)

Summary

The United States (US) Federal Aviation Administration (FAA) continues to be challenged by an increasing demand for Air Traffic Control (ATC) air-ground (A/G) communications frequencies in the 118-137 MHz band. To facilitate this growth, the FAA initiated several strategies to either recover or to obtain additional spectrum resources within the band for ATC. Furthermore, several radical approaches regarding technical and administrative measures were developed and incorporated. These ingenuities became to be known as the “VHF Initiatives.” This paper provides an update on the results of the VHF Initiatives to date.

1. 0Introduction

1.1By the year 2000, it had become difficult to satisfy the ever-increasing VHF A/G communications frequency assignment requirements in the 118 – 137 MHz band. Consequently, the FAA undertook a broad, systematic study that year to ensure that new A/G communication requirements could be satisfied by extending the life of the present system, until 2015 or until a new system could be implemented. The study effort resulted in the identification of 25 improvement measures, which are being pursued within the FAA and through coordination with concerned US Government, non-Government, and International agencies.

1.2These measures consist of resourceful and imaginative concepts addressing administrative, regulatory, and technical matters. The objectives of these ideas are to facilitate frequency assignment processes, to recover un-used frequencies, to obtain other frequencies in the 118 – 136 MHz band for ATC, and to incorporate new schemes in frequency selections.

2.0 Current Status

2.1Currently, five (5) of the VHF Initiatives are actively being pursued during the 2004 – 2005 timeframe. Those initiatives are:

  • The recovery of un-used frequency assignments via a spectrum audit;
  • The expected gain from the spectrum audit is to recover, as many as possible, un-used frequency assignments, and to satisfy, at least, three (3) new high/super-high enroute sector requirements in the enroute environment.
  • The recovery of two (2) discrete VHF frequencies used by law enforcement agencies;
  • One of the two frequencies has already been fully recovered and is available for ATC A/G communication frequency assignment. A negotiation for the remaining frequency continues to be pursued; however, fleet equipage continues to be problematic.
  • The recovery of, at least two (2) of five (5), VHF frequencies previously allocated solely for weather broadcast services utilizing the 121.5 MHz (Emergency Communication Channel) guard-band frequencies;
  • Preliminary engineering frequency plans have been developed to transition weather broadcast facilities to four guard-band frequencies protecting 121.5 MHz.
  • Bench and operational testing at the FAA’s William J. Hughes Technical Center to ensure adequate spurious protection to 121.5 MHz, utilizing filter and other suppression devices, will be completed by the end of February 2005.
  • This measure is expected to recover two, previously allocated frequencies for broadcast services, and make them available for new ATC A/G communication requirements by the end of September 2005.
  • The addition of two (2) usable VHF frequencies for ATC A/G communications, currently allocated for flight tests;
  • In the US, the Aerospace and Flight Test Coordinating Council (AFTRCC) manages a number of VHF frequencies in the 118 – 137 MHz band for flight-testing. The FAA has negotiated to perform a frequency exchange with AFTRCC for two frequencies below 136 MHz for two frequencies between 136.0 – 136.475 MHz.
  • Under this negotiation, the FAA has granted AFTRCC a temporary testing period, not to exceed the end of March 2005.
  • A draft Memorandum of Agreement is being documented and will be finalized by mid-Spring 2005.
  • The addition of two (2) usable VHF frequencies for ATC A/G communications, currently allocated for FAA flight inspections.
  • In the US, Canada, and Mexico, two discrete VHF frequencies have been allocated as flight inspection frequencies. This measure will provide US flight inspection with two frequencies between 136.0 – 136. 475 MHz, in exchange for the two current flight inspection frequencies below 136.0 MHz.
  • Formal correspondences were provided to Canada and Mexico advising them of this potential frequency allotment change during 2004. Canada responded with several inquiries, which yet need to be addressed. No response from Mexico.
  • US flight inspection has been using the two frequencies above 136 MHz for a six month testing period, ending January 1, 2005. Results, comments, and concurrence to switch frequencies are yet to be received.

2.2Major results and activities to-date include:

  • Two abandoned initiatives;
  • Two fully implemented initiatives;
  • One initiative on-hold;
  • Twenty initiatives in various stages of completion;
  • Gain of nine new VHF ATC A/G communication frequencies (total = 535 of 760);
  • Recovery of 50 existing A/G communication frequencies from the audit and re-tuning of facilities to the 121.5 MHz guard-bands;
  • Over 400 new A/G requirements satisfied from the use of these proposals.
  • US implementation of the Domestic Reduced Vertical Separation Minima could not have been achieved on January 20, 2005 without the use of these initiatives.
  • Satisfaction of National Airspace Redesign requirements, in the enroute environment, could not be accomplished without the gains made from the initiatives.
  • VHF Initiatives received International recognition when members from EuroContol’s spectrum office visited FAA HQ for a week long meeting, during August 2004, discussing how EuroControl could implement some of the same strategies in Europe.

3.0Schedule

3.1The five active initiatives outlined in section 2.0, above, will either be fully completed or abandoned (due to non-agreements) by the end of September 2005. All other measures will continue to be pursued until such time frame a new VHF A/G communication system can be implemented.