How WARC '92 will affect mobile services

The US proposals to, and the decisions of, the 1992 World Administrative Radio Conference (WARC '92) that relate to mobile and mobile-satellite services are described. Mobile-satellite service (MSS) issues addressed at WARC '92 include new allocations for low Earth-orbit (LEO) satellite operations, new MSS spectrum allocations, and modifications to current allocations used to support mobile-satellite operations. Allocation issues on the agenda of WARC '92 that related to the terrestrial mobile services include allocations for mobile services between 1 and 3 GHz, allocations for aeronautical public correspondence, and designation of frequency bands for future public land mobile telecommunications services. A number of proposals which were put forward by the US to support MSS allocations and operations that did not explicitly require allocations to the MSS are discussed     

An Introduction to the RARC '83 Plan for DBS Systems in the Western Hemisphere

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 View from Congress

Congressional hearings on the treaty from the 1977 satellite WARC and a possible Senate vote could signal the direction of U.S. policy at WARC '79.     

The Impact of WARC-79 on the Broadcasting-Satellite Service

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.     

The WARC-79 and Papua New Guinea

This paper briefly describes Papua New Guinea, a newly independent country, its telecommunications facilities, and its proposals to the 1979 World Administrative Radio Conference (WARC79), and selected WARC-79 results. The importance of the highfrequency (HF) band is emphasized. It is concluded that most of the requirements of Papua New Guinea regarding the Table of Frequency Allocations were met-although some were not met in the way in which they were first proposed.     

The results of WARC-HFBC (87): technical implications

The planning principles and technical parameters that were decided at the 1987 second session of the World Administrative Radio Conference (WARC) for the planning of the HF bands allocated to the broadcasting service (HFBC) are described. These planning principles and parameters are intended for use in developing test plans to satisfy the world's high-frequency broadcast requirements. Those parameters that were modified at the second session of the conference are discussed toward obtaining a workable and universally acceptable planning system for shortwave broadcasting. With reference to the results of the planning exercises that were used as the basis of decisions at the second session, the likely impact of these decisions on the HF broadcast planning process is described. Some issues that are likely to concern the US broadcasters in preparation for the third session of WARC are summarized in conclusion     

WARC-79 Provisions for Microwave Radio-Relay Systems

This paper reviews 1) the modest changes made by the 1979 World Administrative Radio Conference (WARC) in frequency allocations between 1 and 40 GHz which affect the design and operation of radio-relay systems, 2) new allocations which open up the use of frequencies between 40 and 400 GHz, and 3) the related technical regulations, particularly those governing the sharing of frequency bands with other services.     

What is the World Administrative Radio Conference?

A primer on WARC describes the background of issues and interests at stake when the Conference meets next autumn in Geneva.     

Implications for Development Communications

A synopsis of WARC issues focuses on developing countries' access to reliable, affordable communication technology appropriate for their development needs.     

Global development of PCS

A brief survey of international efforts to address spectrum and incumbency issues and implement new personal communications services (PCS) is presented. Worldwide frequency allocations agreed to in the 1992 World Administrative Radio Conference (WARC 92) are discussed. The development of personal communication services in European, Asian, and North American countries is reviewed     

A reassessment of satellite communications in the 20 and 30 GHz bands

Notwithstanding the additional spectrum allocations of the 1979 World Administrative Radio Conference (WARC '79) and the ever-increasing sophistication of spacecraft antennas which allow more intensive spectrum reuse, saturation of the 6/4 and 14/11 GHz bands is foreseeable by the late-1990s. The next available frequency bands at 30/20 GHz were allocated at WARC '71, when knowledge of propagation phenomena and their effect on satellite communications systems performance was fragmentary. During the past 8 years, numerous experimental programmes have led to the acquisition of more precise information about hydrometeor-induced propagation disturbances. Analysis of the data reveals that even with corrective means such as diversity and coding, service reliability of satellite communications systems with up-links at 30 GHz and down-links at 20 GHz could not reach 99.99 per cent as currently available at the lower frequencies and could be 98.0 per cent, or lower, in certain parts of the world. Since the conventionally proposed use of the 30/20 GHz bands does not lead to optimal solutions, alternative approaches are needed. An approach which would involve a revision of the spectrum allocations at 30/20 GHz is proposed. Placing both up- and down-links around 20 GHz and redistributing the spectrum available at 20 GHz would prevent the intrinsic imbalance of the up- and down-links with consequent higher reliability, reduced earth-station transmitter power, reduced construction and operational costs, and simplification of the spacecraft transponders and antenna design. The use of frequencies around 30 GHz could be postponed until the 20 GHz bands became saturated. When the 30 GHz bands would eventually be used, there would be no imbalance of up- and down-links.     

The Impact of WARC-79 on Space Applications

Prior to the 1979 World Administrative Radio Conference (WARC-79), no frequency bands were allocated for remotesensing measurements. Actions taken by the WARC insure that frequencies will be available for such use, and that operations can be conducted without harmful interference on a worldwide basis for the benefit of all nations. Allocations employed for transfer of scientific data from spacecraft in all regions of space from near-Earth orbit to deep-space planetary ranges were significantly improved. New global allocations for Earth exploration-satellites will permit worldwide acquisition of Earth exploration data both via direct transmission and via relay satellites. New allocations for meteorological satellite data transmission will permit wide-band applications such as direct reception of highresolution picture data by users. Satellite-aided search and rescue systems will benefit from WARC decisions to allocate frequencies exclusively for emergency radiobeacon systems using space techniques. Bands to provide links between the satellite and Earth were designated for distress and safety operations. Time and frequency services with accuracies in the 10- to 50-ps range, needed to meet future system requirements for precise time and frequency information, will be possible because of WARC actions to allocate frequency bands with suitable bandwidth for these services. The search for communications from extraterrestrial intelligence was afforded a degree of protection near several spectral lines of basic physical interest.     

Regulatory Procedures and WARC-79

There are two major elements of a General World Administrative Radio Conference such as WARC-79. One is to review and revise allocations of radio frequencies to functional services such as fixed, mobile, satellite, and radionavigation. The other major element is the detailed radio regulations concerning use of these allocations by member Administrations. These regulations combine technical, economic, geopolitical, and other considerations into a framework which attempts to satisfy the perceived requirements of all Administrations. This aspect of WARC79 is the subject of this paper. As will be seen, some substantial changes in regulations were made at the Conference, especially those concerning HF assignments and use. Other changes are implicit in the Resolutions for future conferences which were adopted at WARC-79. The key to success in framing effective and acceptable allocations, and regulations, is cooperation. In this respect, WARC-79 was not much different from preceding conferences, despite contrary misgivings.     

Spectrum sharing considerations for the proposed ESA ‘archimedes’ satellite DAB service

At the 1992 World Administrative Radio Conference (WARC), spectrum was allocated, on a primary basis, to the broadcast satellite service (sound). The allocations were not, however, uniform worldwide, nor will the BSS(S) have sole use of these allocations. In addition, many countries have reserved primary use of the spectrum for existing services until 2007, with the BSS(S) permitted only on a noninterference basis. This situation will impose serious constraints on the proposed ESA S-DAB service, to be radiated from the ‘Archimedes’ constellation of satellites. The launch date for this service may be before the end of the century, and sharing with other spectrum users will therefore be necessary. Such users include fixed telephony links, broadcast links and mobile aeronautical telemetry. This paper reviews current spectrum usage in Europe and elsewhere, and investigates the restrictions thus imposed on the ESA S-DAB service. Numerical examples based on real-world systems are given, and demonstrate the feasibility, in many cases, of spectrum sharing.     

The Hidden Agenda

"Should the hidden agenda become the overt agenda, and defense communications become a major issue, then WARC could assume high diplomatic and policy significance."     

The Post-WARC Frequency Situation in Central Europe

This paper discusses the results of WARC-79 from the standpoint of a frequency manager in Central Europe. In this part of the world, extensive use is made of radio communication, and it is in close proximity to other regions with different communications needs and regulatory philosophies. Both of these factors make frequency management difficult. The paper discusses the most important decisions of the Conference as well as their impact on Central European frequency management. The bands below 30 MHz, 30-1000 MHz, 1000 MHz-40 GHz, and above 40 GHz are treated. It is concluded that WARC results, in general, are acceptable in Central Europe, although not all requirements for this region have been met. An orderly development of radio services is envisaged that will satisfy needs of the area over the next twenty years.     

Mobile radio: An overview

Following a brief prologue and historical overview, such technical issues as the repertoire of systems and services, management of the airwaves, the operating environment, service quality, network issues and cell size, channel coding and modulation, speech coding, diversity, multiplex, and multiple access (FDMA, TDMA, CDMA) are discussed. Also addressed are the potential economic and sociological impacts of mobile radio communications in the wake of the redistribution of airwaves at the World Administrative Radio Conference WARC '92. Performance dependence on multipath delay (related to the cell size and terrain configuration), Doppler frequency (related to the carrier frequency, data rate. and the speed of vehicles), and message length (may dictate the choice of multiple access) is briefly discussed     

2.6 GHz band satellite ISDB system for mobile reception

At the World Administrative Radio Conference (WARC)-92, the 2.6 GHz frequency band was allocated to a group of East Asian countries including Japan. This band is being studied for use in mobile multimedia broadcasting. This paper describes the outline of a system for 2.6 GHz band mobile multimedia broadcasting services, together with its requirements. In particular, the effects of the broadcasting signals attenuation due to shadowing by buildings and foliage, and the signals deterioration due to multipath propagation and fading, must be taken into account in order to realize the 2.6 GHz band system. This study considers the economic and technical constraints related to the modulation schemes, transmitting power, satellite antenna reflector aperture, the gain of the receiving antennas and the scale of the satellites. The configuration of satellite hardware systems based on the channel plan, channel bandwidth, and other specifications is investigated taking into account of these constraints. For example, a bit-rate of 4.8 Mbps can be provided when a 2-ton class satellite bus is utilized. This indicates that 2.6 GHz band services are technically feasible     

Summary of conclusions of the 1992 World Administrative RadioConference

The major decisions made at the conference are briefly described. Additional frequency bands for shortwave (HF) radio broadcasting were agreed upon. Frequency allocations were made to support a number of US proposals, to provide advanced mobile radio services using low Earth orbit satellites. Allocations for land based mobile services adopted at WARC '92, in the range 1700 to 2600 MHz, are meant to foster improved mobile services that can be used worldwide. An allocation was also made to support commercial telephone service between passengers flying on aircraft and individuals on the ground. Allocations were made for sound broadcasting from satellites, as well as for providing a means to accommodate a complementary terrestrial-based digital audio broadcasting service. New frequency allocations to support space activities were agreed upon, and an allocation was made to the fixed satellite service in the band 13.75 to 14.0 GHz