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     

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     

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     

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.     

Europe prepares for WRC-95: mobile satellite service issues

European preparations for World Radiocommunication Conferences are coordinated within the European regional posts and telecommunications organization known as the CEPT. The basic objective of the European proposals is to achieve an even playing field for the introduction of competitive mobile satellite services that can provide global services from the earliest feasible common date. Europe believes the additional allocations made at the 1992 conference are sufficient for the foreseeable future, especially now that there is an opportunity every two years to make additional allocations should the need be proven. What must be agreed upon, however, are the allocations for the feeder links to the mobile satellite service to complement the 1992 allocations for service links. Europe also need to consider the technical constraints that were placed on the use of these service links at the 1992 conference. Of particular concern to Europe, is the most unsatisfactory conclusion in 1992 on the date of availability of the 2 GHz mobile satellite service allocations. The article describes the European proposals on these mobile satellite issues     

Regulatory flexibility in commercial satellite communications

MSAT, a domestic mobile satellite service (MSS) system under development in the US, is addressed. The high effective isotropic radiated power (EIRP) of each MSAT satellite, which is orders of magnitude greater than any existing L-band satellite and will allow the introduction of new services, and the economics of MSAT are discussed. The RadioSat system currently being developed, which is optimized for services that support enormous numbers of mobiles on each MSAT channel, is briefly described. The highly flexible MSS regulatory structure established by the US Federal Communications Commission (FCC) is examined     

Service, system, and technology considerations for space-basedinternational radio broadcasting used in the conduct of public diplomacy

It is argued that the technology and operating characteristics of a space-based international radio broadcasting system designed to meet the service needs of the world's governments in the conduct of public diplomacy in an effective and efficient fashion now can be clearly seen. It is concluded that the international public diplomacy radio broadcasting community now should position itself to assist in seeing that the kind of system and service it needs is forthcoming. For instance, it should see the appropriate frequency allocations, preferably at L-band, are made available at the WARC '92 conference. In addition, generally, it should position itself to see that it makes the transition from surface-based software to space-based UHF in a sensible, paced and prudent fashion     

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.     

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.     

Mobile communications

An important issue facing the 1992 World Administrative Radio Conference, namely, determining how to provide additional spectrum for both existing and entirely new mobile services, is examined. At least six types of mobile systems will be seeking new or expanded allocations; three involve satellites and three rely on primarily terrestrial techniques. All but one will be forced to compete for allocations in the same crowded 1-3 GHz frequency range. The various allocation proposals 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.     

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.     

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.     

Land mobile satellite systems

The general advantages and potential operating characteristics of the mobile satellite service (MSS) are described, and distinctions are made between radio telephone, which is interconnected to the public switched telephone network, and private mobile radio systems. Mobile satellite service offers voice, data, position location, and paging services, interconnection to the public switched telephone network, and the possibility of private networks. Performance and cost characteristics are given along with summaries of market needs and market demands. The space and ground systems of the MSS are described     

Personal communications services

The history of the US Federal Communications Commission (FCC) examination of proposals to allocate radio frequency spectrum to a new and innovative range of services it calls personal communications services (PCS) is outlined. Personal communication networks (PCN), which will supply mobile two-way, mass-market communications services, the most advanced offering of the PCS area, and spectrum allocation for PCS are discussed. The results of a consumer market study of the potential for PCN services are also 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     

Provisions for High Frequency Future Use

An area of widespread interest at the 1979 World Administrative Radio Conference (WARC-79) was concerned with allocation proposals related to the modification of the high-frequency (HF) (4-27.5 MHz) portion of the spectrum. From a wide range of proposals, the Conference adopted allocation provisions that reduced the exclusive fixed-service bands by two-thirds, made significant allocations to the broadcasting and maritime-mobile services, and provided somewhat lesser spectrum provisions for the amateur service. Shared use of fixed bands by the mobile service was greatly increased. Few changes were made to aeronautical service allocations. Provisions were planned to remove an unused fixed-service assignment from the International Telecommunication Union (ITU) Master Frequency Register, and to provide special assistance to Less Developed Countries (LDC's) to enable them to better meet their fixed requirements. A conservative schedule of changes, through 1994, was adopted, including several specialized planning conferences to assist in optimizing the use of HF bands. With continued national needs and improved technology being developed and adopted by the ITU member countries, systems in all authorized HF services will be widely used to meet requirements of the world community for a long time to come.     

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     

一种新的移动数据业务运营支撑方案

首先介绍了现有运营支撑系统对移动数据业务的支撑现状以及存在的问题,然后提出了一种基于分层体系结构、可扩展、可配置的移动数据业务运营支撑方案,分析了此方案的总体结构和子系统组成,与现有运营支撑系统相比,该方案在很大程度上提高了移动数据业务的支撑效率和上线速度,最后对此方案的实现和应用情况做了说明.