The 1983 Regional Administrative Radio Conference (RARC '83), sponsored by the International Telecommunication Union (ITU), adopted a plan that assigns to each country in ITU Region 2 (the western hemisphere) the frequencies and orbital positions it can use for direct broadcasting satellite (DBS) systems in the 12.2-12.7 GHz band. An earlier ITU conference, the 1977 World Administrative Radio Conference (WARC '77), had already made such a plan for countries of ITU Region 1 (Africa, Europe, the Soviet Union, and Mongolia) and Region 3 (the rest of Asia, Australia, and the southwest Pacific) in the 11.7-12.5 and 11.7-12.2 GHz bands, respectively. In addition to orbital positions and frequencies, both plans specify the satellite polarization, coverage, and maximum radiated power to be used by each country. This paper describes the RARC '83 Plan and compares some of its features to those of the WARC '77 Plan. The reference system parameters used for planning at RARC '83 and WARC '77 are summarized and discussed briefly. The RARC '83 Plan itself is described in terms of the satellite coverage areas; the channelization of the band; and the specific orbital position, frequency, and polarization assignments provided. Further details about the assignments in the plan and an assessment of their impact on the development of DBS systems in Region 2 are also included.

The prospective operator of a system intended primarily for broadcasting directly to homes in the United States (as opposed to distributing programming to CATV head ends or terrestrial broadcasting stations) must choose between two frequency bands: 12.2-12.7 GHz and 11.7-12.2 GHz. The first of these bands is allocated to the broadcasting-satellite service (BSS) with the assignment of frequencies, orbital positions, sense of polarization, and maximum radiated power to service areas governed by an international plan. The other band is allocated to the fixed-satellite service (FSS), but with a footnote permitting use of transponders already authorized in the FSS to be used for BSS transmissions under certain constraints on maximum radiated power and mutual interference. This paper examines the differences between the two frequency bands in terms of their impact on a number of factors of practical interest to a DBS system operator.

The Fixed-Satellite service (FSS) is the most heavily used and still the fastest growing of the seventeen space radio communications services recognized by the International Telecommunication Union (ITU). To provide the additional spectrum needed for continued growth in both domestic and international satellite networks, the ITU's 1979 World Administrative Radio Conference (WARC-79) more than doubled the bandwidth allocated to this service in most parts of the spectrum. The Inter-Satellite service (ISS) is an "auxilliary" service whose allocations are intended to provide intersatellite links between the space stations of other services. Although not yet implemented in commercial systems, such links are expected to be used extensively in future FSS networks. To permit the introduction of the ISS earlier and at lower cost than would be possible with the existing allocations above 50 GHz, WARC-79 allocated two 1-GHz-wide bands to the ISS at 23 and 33 GHz. The Mobile-Satellite services (MSS) include land, maritime, and aeronautical components. WARC-79 left the Aeronautical-Mobile Satellite allocations essentially unchanged, created new possibilities for development in the Land-Mobile Satellite service, and essentially doubled the spectrum that will be available to the Maritime-Mobile Satellite service. WARC-79 made only minor changes to the regulatory procedures for gaining access to the various space service allocations. However, in response to the concerns of developing nations about equitable access to the spectrum and the geostationary satellite orbit for future satellite systems, WARC-79 resolved to convene another World Administrative Radio Conference in two sessions scheduled for 1984 and 1985 (WARC-84/85). This Space Conference would consider the use of the geostationary satellite orbit and the planning of the space services using it with the objective of guaranteeing in practice for all countries equitable access to the orbit. This paper provides a detailed description of the WARC-79 allocation actions affecting the FSS, ISS, and MSS and provides background on the decision to convene WARC- 84/85.

The World Administrative Radio Conference, Geneva, Switzerland, 1979 (WARC-79) decided many of the international issues facing the Broadcasting-Satellite service (BSS) and adopted Resolutions and Recommendations dealing with most of the others. This paper identifies the BSS issues considered at WARC-79, describes the actions taken during the Conference, indicates the current status of subsequent WARC-mandated activities involving the BSS, and assesses the potential impact of the WARC on future BSS systems.