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     

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     

Planning aspects of satellite and terrestrial digital sound broadcasting

DAB is one of the most promising sound broadcasting techniques for the future. It will soon start terrestrial operations, and later on will be used for satellite broadcasting. The Eureka 147 DAB system is based on a set of well-demonstrated techniques, in particular the MUSICAM coding, adopted by MPEG, and OFDM modulation. It allows great spectrum efficiency, profiting from the single frequency network concept, one of the most interesting characteristics of the system. However, frequency problems remain a difficulty, as DAB must either examine the possibility of entering existing heavily used frequency bands or wait until the new frequency bands allocated by WARC 92 become fully available. For terrestrial broadcasting, most interested operators, broadcasters and manufacturers are convinced that appropriate solutions will be found and that DAB will start operational services from about 1996. In Europe, a CEPT planning conference will address the matter in 1995. Satellite broadcasting may come later. Short wave broadcasters examine possibilities to replace short waves, the quality of which is so poor, by digital satellite broadcasting. From the frequency spectrum point of view, this raises the difficulty of sharing frequency allocations with terrestrial applications.     

Impact of WARC-79 on the Studies of International Radio Consultative Committee (CCIR)

The CCIR provided the main technical bases for the World Administrative Radio Conference, 1979, including terminology; technical bases for allocation, regulation, and for the provision for new services; characteristics of equipment and emissions; radio wave propagation and noise data. The WARC specified CCIR studies to be carried out for a number of future radio conferences to be held in the 1980-1986 time period, including a conference in 1983 to plan satellite broadcasting in the region of the Americas and a world conference in 1984/1986 concerning the geostationary satellite orbit. Additional studies set out for technical radio regulations included, for example, determination of coordination area around an Earth station in the bands from 1 to 40 GHz shared between space and terrestrial services, and other technical criteria for frequency band sharing. Over the next few years, because of the intense schedule of ITU administrative radio conferences, CCIR studies related to frequency sharing and other radio regulations will increase markedly.     

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.     

Space communications

Six proposals for enhancing or expanding the electromagnetic spectrum allocated for communications supporting research in space, which will be heard by the 1992 World Administrative Radio Conference, are discussed. They will cover extravehicular activities, space operations, data relay links, deep space interplanetary probes, future planetary missions, and Earth exploration satellites. Of primary importance to most space agencies is the need to improve the status of the allocation of the space research, space operations, and Earth exploration satellite services in the bands 2.025-2.110 GHz and 2.20-2.29 GHz     

WARC Allocations and Some of their Impacts on Japan and in Asia

This paper describes certain decisions made at the World Administrative Radio Conference (WARC) held in September 1979 which will have great impact on the utilization of radio in Japan and throughout Asia and Oceania. This paper concentrates on the table of frequency allocations adopted at the conference. It also outlines some of the problems expected at the forthcoming WARC for high-frequency broadcasting (WARC-HFBC) and on the space services planning conferences.     

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.     

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.     

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     

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.     

INTERFERENCE AND SHARING CONSIDERATIONS BETWEEN THE SPACE OPERATIONS/SPACE RESEARCH SERVICE AND NEW APPLICATIONS OF THE FIXED SERVICE NEAR 2 GHz

Many satellite projects use radio frequencies in the bands 2025–2110 MHz and 2200–2290 MHz for spacecraft operations and data transmission. Frequencies below a few GHz are of particular interest because of favourable propagation conditions and attractive antenna designs. The above bands have to be shared with the fixed service and the mobile service. The fixed service has announced plans for the introduction of vast quantities of a new type of application, referred to as the point-to-multipoint system to be used for data distribution or local access systems. At International Telecommunications Union (ITU) meetings, scenarios assuming the worldwide deployment of more than one million new fixed service installations have been presented. This paper assesses the interference potential from point-to-multipoint systems to conventional direct links between spacecraft and earth stations. The interference into the space as well as into the ground segment has been investigated. Typical earth stations with a 15 m dish size have been assumed. Interference received at low earth orbiters as well as geostationary satellites has been evaluated. It is shown that sharing will not be possible without technical or operational constraints on the fixed service systems. © 1997 by John Wiley & Sons, Ltd.     

Space radio services and WARC-MOB-87

A recent conference of the ITU has agreed upon worldwide frequency allocations near 1600 MHz for communication by satellite with mobile stations on land, and has permitted the use of some aeronautical mobile-satellite frequency bands for passengers' in-flight telephone calls to the ground. Frequencies for systems for locating mobile stations by radio, using satellites, were allocated.     

A modified rain attenuation prediction model for tropical V‐band satellite earth link

Radio wave propagation plays a very important part in the design and eventually dictates performance of space communication systems. Over time, the requirements of satellite communication have grown extensively where higher capacity communications systems are needed. Escalating demands of microwave and millimetre wave communications are causing frequency spectrum congestion. Hence, existing and future satellite system operators are planning to employ frequency bands well above 10 GHz. The challenge in operating at such high frequencies for communication purposes is that there exists stronger electromagnetic interaction between the radio signals and atmospheric hydrometeors. Such instances will degrade the performance of such high frequency satellite communication systems. The development of a revised model for a better‐improved rain fade prediction of signal propagations in tropical region is considered very important. Researchers and engineers can employ the model to accurately plan the future high frequencies satellite services. Copyright © 2014 John Wiley & Sons, Ltd.     

The global frequency spectrum management: Prospects and problems

The rapid development of demand for communications services worldwide will bring about a serious shortage of spectrum availability in the near future, particularly in the key satellite and terrestrial microwave areas. This is especially true in the United States in the next ten years, but will in all likelihood apply worldwide by the end of the century. Unprecedented demand for satellite communications capacity is anticipated as developing countries realize the benefits to growth and economic well being the investment in communications facilities can bring. This article addresses the developing trends, and the relationship between communications and socioeconomic variables. Solutions addressed include increasing the efficiency of present services, and examining the allocation process at the national level. Management attention is addressed in particular in the area of spectrum allocations at the national level.     

Satellites free the mobile phone

A variety of satellite systems, soon to go into orbit, will bounce voice and data between wireless handheld phones anywhere on Earth. Peripatetic users will be able to switch at will between conventional terrestrial service and the new satellite systems wherever they roam. Some of the satellite-based land mobile services are or will be worldwide, others cover broad geographical regions. All are characterized by the magnitude of the capital being invested-in the billions of US dollars-and by sweeping transnational business alliances. Virtually every one of these wireless efforts has given rise to international partnerships, often involving satellite manufacturers, cellular service providers, electronic equipment companies, and telecommunications entities. In addition, satellite systems are going into orbit to supply other services besides dialup telephones     

Services, technologies, and systems at Ka band and beyond-a survey

This paper discusses system and technology aspects crucial to the development of satellite communications at Ka band (20-30 GHz) and beyond. It surveys the evolution of Ka band geostationary Earth orbit (GEO) satellite communications until the present stage of development of systems for direct-to-user (DTU) provision of interactive multimedia services worldwide. Then it discusses the attenuation problem and main technical issues of this new technology. Finally, it provides a view on experiments and technological developments at extremely high-frequency (EHF) bands     

Broadcasting

Three major allocation issues involving the broadcasting and broadcasting-satellite services that will be discussed at the 1992 World Administrative Radio Conference (WARC-92) are examined. They are expansion of frequencies for conventional high-frequency (shortwave) broadcasting, new frequencies for both satellite and terrestrial digital audio (radio) broadcasting to handheld and automobile receivers, and new frequencies for studio-quality high-definition television broadcasting from satellites. The bands that are viable candidates for these services are discussed     

The maritime radio spectrum future

Future satisfaction of the electromagnetic spectrum needs of the maritime mobile service is dependent on the translation of those needs to frequency allocations. In September 1979, over 100 countries will consider all of the spectrum, and make changes to meet perceived needs of radio services, including maritime needs up to the year 2000. This conference, the World Administrative Radio Conference 1979, will have a significant impact on future maritime radio operations. Issues, procedures, competing requirements, are explored to enable a better understanding of the regulatory process for frequency allocations.