Long-term spectrum planning is critical to the efficient development of spectrum-dependent telecommunications services. Forecasting the demand for these services and allocating adequate spectrum for radio services in advance will assure that these telecommunications services are provided in a timely and efficient manner. Further, early identification of available spectrum for an intended use gives manufacturers adequate lead time to design and manufacture equipment for the planned frequency bands, and provides the lead time demanded by Federal budget cycles.

The National Telecommunications and Information Administration (NTIA), under a mandate from Congress to develop long-range spectrum plans, initiated the Strategic Spectrum Planning Program. As part of this long-term planning effort, NTIA released a report, U.S. National Spectrum Requirements: Projections and Trends (hereinafter NTIA Requirements Study) in March 1995 addressing all radio services, and found that eight of these services needed access to additional spectrum in order to satisfy user requirements to the year 2004.

While all radiocommunications are important to the nation, one of the critical needs for spectrum is to satisfy user requirements in the 3-30 megahertz (MHz), high frequency (HF) portion of the electromagnetic spectrum. The NTIA Requirements Study identified five radio services requiring access to additional HF spectrum. Current HF spectrum is congested in many countries and various parts of the world, and the number of systems is expected to increase in the next 10 years. Additionally, the demand for HF spectrum is driven by societal needs, such as demands for increased safety for maritime and aeronautical operations, the increased need for international broadcasting, and recreational uses of the HF spectrum. All these factors indicate that demand for HF spectrum will continue to increase. This report focuses only on those radio services having HF spectrum requirements. Spectrum requirements of the other radio services will be addressed in the future.

National policies can address the problem of increased demand for spectrum in a number of ways. One way is to place greater reliance on market-based forces to guide spectrum apportionment. NTIA in its NTIA Spectrum Policy Study (U.S. Spectrum Management Policy: Agenda for the Future) and elsewhere has examined the use of market-based forces to guide spectrum apportionment. NTIA is mindful that when spectrum is commercially non-viable or when spectrum is required for the public interests (public safety, national defense, education, etc.), market forces may not be the ideal spectrum management approach to satisfy increased demand for spectrum. Because of the nature of some frequency bands and radio service allocations, the existing practice of

long-range spectrum planning where spectrum is re-allocated for shared or exclusive use may be an alternative approach to satisfy increased spectrum demands.

This report examines the additional HF spectrum requirements for the maritime mobile, aeronautical mobile, mobile, amateur, and broadcasting services previously identified by NTIA. This spectrum availability study for the five radio services was prepared as a single document because satisfying the spectrum requirements for one of these services directly affects the other radio services in the HF band. This report examines four general long-range planning options for increasing spectrum availability, investigates the allocated spectrum between 3-30 MHz suitable for these radio services' HF spectrum requirements, and identifies a number of frequency bands that could satisfy these radio services' HF spectrum requirements.

High frequency radiocommunications are used by both the private sector and the Federal agencies. These uses and operations include vessel and aircraft control, distress and safety of life communications, emergency and disaster relief communications, broadcast services, and recreational uses by hobbyists.

HF Spectrum Requirements

The NTIA Requirements Study found that approximately 3,088 kilohertz (kHz) of additional spectrum or a reallocation of about 11 percent of the HF band will be needed for radiocommunications in the HF band for the five radio services: broadcasting, amateur, aeronautical mobile, mobile, and maritime mobile. The aggregate U.S. requirement for additional HF broadcasting spectrum was calculated to be approximately 1,900 kHz, since separate requirements were not mutually exclusive between Federal and non-Federal broadcasters. The amateur service requested expansion and upgrading of its allocations for a total of about 900 kHz. The aeronautical mobile service for route (R) and off-route (OR) operations required an additional 108 kHz and 30 kHz, respectively, and 100 kHz additional in the mobile service to support aeronautical operations. An additional 36-60 kHz was required for maritime mobile service.

High Frequency Usage

The frequency spectrum from 3-30 MHz has been very important because of its national and international uses. Many developed countries use HF for radiocommunications to and from aircraft and ships, international broadcasting, amateur operations, and for fixed long-distance radiocommunications. While little use is made of HF radiocommunications in the United States and other developed countries for domestic communications, lesser developed countries still find HF cost-effective for their domestic radiocommunications needs, such as for national broadcasting, mobile, and fixed point-to-point communications. Re-allocation in the HF band is a "zero sum" process since any allocation gain for one radio service is generally at the expense of another radio service.

Long-Range Planning Options

When HF spectrum demands exceed available allocations, there is a limited set of long-range planning options possible to satisfy the demand for spectrum access. For the purposes of this study, four long-range planning options for additional spectrum access were addressed. These options are: (1) utilize higher frequencies (above 20 gigahertz (GHz)); (2) reaccommodate incumbent spectrum users to other frequency bands; (3) make more efficient use of current frequency allocations by use of advanced technologies; and (4) use non-spectrum technologies such as fiber optic cable instead of radio spectrum.

Generally, long-range planning options for HF radiocommunications were limited to those bands between 3-30 MHz because of propagation considerations. With respect to spectrum that could be made available for allocation to the five radio services, the primary focus was on those frequency bands currently allocated to the fixed and fixed/mobile services. The fixed and shared fixed and mobile services were the only significant radio services found not to require additional spectrum.

For the purposes of long-range spectrum planning, the frequency bands outlined below could be considered for satisfying future HF radiocommunications spectrum requirements: