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WRC-97: the next challenge

by Robert Jones
Director, Radiocommunication Bureau

The conclusions of World Radiocommunication Conferences (WRC) are enshrined in Final Acts which represent binding intergovernmental treaties. Therefore, a successful conference needs a realistic agenda that must be prepared carefully and consensus reached between Member States of the Union on the issues to be treated.

This article is intended to describe the basic issues to be considered at WRC-97, to recall some of the preparatory activities and to indicate a few of the more sensitive issues. No doubt many more complete analyses will be written once the Conference is over.

The issues on the agenda can be roughly grouped under six headings:

These key issues and the need to prepare for an informed debate to facilitate decision-making at the Conference has put a very heavy workload on the Member States, interested Sector Members and the Radiocommunication Bureau (BR). To help ensure good preparations, BR has worked very closely with regional entities, inter alia, the Asia-Pacific Broadcasting Union (ABU), the Asia-Pacific Telecommunity (APT), the Arab States Broadcasting Union (ASBU), the respective units of the European Conference of Postal and Telecommunications Administrations (CEPT), the Inter-American Telecommunications Commission (CITEL), the European Broadcasting Union (EBU), the Pan African Telecommunication Union (PATU) and the Union of National Radio and Television Organizations of Africa (URTNA).

Fortunately, most of the engineers and administrators involved in the preparations had gained some (exhausting) experience in previous conferences. So, immediately after the last conference, (WRC-95), they designed an efficient framework for carrying out preparatory studies. In this regard, the Conference Preparatory Meeting (CPM) has been of tremendous value to WRC-97. As the Chairman of the CPM, Robert Taylor (United States) put it at the end of their meeting in May 1997, "despite the fact that no decisions were being debated, many of the deliberations of the CPM were as detailed and as hard-fought as those which take place within a conference proper".

The result of this preparatory work is compiled in the CPM Report on technical, operational and regulatory/procedural matters to be considered by the 1997 World Radiocommunication Conference. The report has been published as a basic conference document.

Looking at the agenda items and reading through the CPM Report, some general observations can be made.

In the context of regulatory/procedural matters, the Conference will review the provisions of the simplified Radio Regulations, as adopted by WRC-95, and will endeavour to remove all inconsistencies before these Regulations enter into force on 1 June 1998. By way of example, some inconsistencies have been identified between the provisions of the new Article S9 (Procedure for effecting coordination with or obtaining agreement of other administrations) and the corresponding procedures in Appendices S30 and S30A. The CPM Report gives possible approaches to addressing these inconsistencies, including examples of changes that could be made to the various provisions governing coordination.

The CPM Report also suggests amendments to the procedure in RR No. S13.20. Adoption of these amendments would require BR to prepare, when appropriate, draft amendments or additions to the Rules of Procedure (governing the activities of the Radio Regulations Board (RRB) as well as those of BR itself in the application of the Radio Regulations) and to make such drafts available to the Member States for comment before they are submitted to the RRB for consideration. The proposed amendments foresee the publication and circulation of such drafts at least three months prior to the meeting of the RRB. If accepted by WRC-97, such an obligation would virtually prevent any rapid reaction by the RRB to a given problem that may arise in the processing of frequency-assignment notices by BR. The unavoidable delays in the provision of guidance for the handling of such transactions by BR could have a delaying impact on its service to administrations.

The provisions of Article 17 of the Radio Regulations which regulate the use of the HF bands allocated exclusively to the broadcasting service have been in place since 1959. Their approval was preceded by arduous negotiations. Indeed, the discussions on the need for a satisfactory HFBC planning system, which hopefully should be concluded at WRC-97, started in 1979 and were continued at the World Administrative Radio Conferences (WARC) of 1984 and 1987. These efforts failed as, even with additional allocations, a planning method capable of satisfying all of the stated requirements of administrations could not be developed and implemented.

During all these efforts, the relatively simple procedures of Article 17 continued to be applied with some success. That success has been based on the considerable coordination activity carried out by the interested parties outside the International Telecommunication Union (ITU), the results of which have then been communicated to the Union for further processing. Given these experiences, in the preparations for WRC-97, a flexible procedure has been worked out, based on explicit principles, that provides for coordination through administrations and broadcasters either directly or in regional or interregional meetings of two annual HFBC schedules (March-October and October-March). Most people are optimistic that this flexible coordination procedure will be accepted at WRC-97, hereby putting an end to very long-standing discussions! If this happens, what remains to be done would be the drafting of appropriate regulatory text covering the introduction of single-sideband (SSB) transmissions and other techniques in the HFBC bands.

Several operational provisions for the maritime mobile and maritime mobile-satellite services (and for the corresponding aeronautical applications) need overhaul to reflect evolution towards the GMDSS, which is to be fully implemented on 1 February 1999 in the context of the International Convention for the Safety of Life at Sea (SOLAS). Specific requirements for procedural updates have been identified for communications between GMDSS equipped ships and non-GMDSS ships, the use of ship information by search and rescue (SAR) authorities, calling procedures, licensing and the conditions to be met before issuing required operators’ certificates. Measures such as reduced channel spacing or digital techniques are proposed in order to enhance the use of the frequencies in the bands 156–174 MHz by stations in the maritime mobile service and to deal with congestion on calling and port working channels which could compromise safety and operational efficiency. Hopefully, no basic controversial discussions should occur on this agenda item.

"Issues concerning existing and possible additional frequency allocations and regulatory aspects as related to the mobile-satellite and fixed-satellite services" (Agenda item 1.9.1) will certainly lead to many more discussions. Mobile-satellite service systems employing low-Earth orbits (LEO) and other species such as medium-Earth orbits (MEO), and high-Earth orbits (HEO) are trying to come to life in a highly congested spectrum. These systems need feeder links and would like them in the 5/7 GHz, the 15/19 GHz and in the 29/19 GHz bands, where they come up against interests of the terrestrial fixed service and the fixed-satellite service (FSS), just to name a few.

Below 1 GHz, the situation today is that 1525 and 1900 MHz are allocated worldwide in the up and down directions, respectively, on a primary basis for the mobile-satellite service (MSS). Between 7 and 21 MHz of spectrum is considered necessary by various communities, but satisfying such demand will be a challenge. Extensive and complicated sharing scenarios have been worked out, many of them requiring additional studies. The study of the sharing possibilities between non-GSO Earth-to-space links and the land mobile service in the band 148-149.9 MHz points to this need. In one such study, non-GSO networks providing data services were modelled assuming 48 satellites in eight orbital planes in 950 km altitude circular orbits operating twenty-four hours per day using dynamic channel assignment techniques. Such a system could cause interference to a conventional land mobile user with a mean time between events of ten hours to twenty-one months. Similar conclusions were arrived at for the 460 MHz band. WRC-97 will have to decide what is acceptable.

Similarly, the L-band between 1 and 2 GHz has been thoroughly analysed to determine additional sharing possibilities, with limited success. Band segmentation, separation distances, enhanced antenna design and operational arrangements are among the limited sharing possibilities identified. In the bands around 2 GHz, sharing between the terrestrial fixed service and the MSS is a controversial question in view of the extensive deployment of terrestrial radio relay systems and the growing interest of future MSS operators to use the bands as early as possible. Such operations are also essential for the support of terrestrial mobile systems in the context of IMT-2000 (formerly, future public land mobile telecommunication systems, or FPLMTS) and global mobile personal communications by satellite (GMPCS). Divergent views and serious concerns govern the question of whether or not to increase or change the 2 GHz allocations for MSS.

Another hot issue will be the sharing between GSO/FSS networks and non-GSO/MSS feeder link networks in bands around 20 and 30 GHz. Adaptive power control, high gain antennas, geographic isolation between earth stations, satellite and site diversity as well as traffic management have been identified as primary techniques for mitigation of interference between the different systems intending to use these bands. Similar techniques may also be considered should discussions occur tempting to "refine" further the provisions of Resolution 118 which regulates the use of the bands 18.8–19.3 and 28.6–29.1 GHz by non-GSO/FSS systems as well as the relations between GSO and non-GSO FSS systems. Divergent interpretations of RR No. S22.2 (Control of interference to geostationary-satellite systems) will add some flavour to the debate. Last but not least, the handling of expanding spectrum requirements for future non-GSO MSS feeder links in this region of the spectrum will have to be decided upon by WRC-97.

Space science services include systems for active and passive sensing. Active sensing is the measurement on board a spacecraft of signals transmitted by sensors and then reflected, refracted or scattered by the Earth’s surface or its atmosphere. Passive sensing does similar measurements of naturally radiated electromagnetic energy. Results of measurements are used for meteorology and for climatic studies, determination of roughness of large objects such as ocean waves and the production of high resolution images of land and sea. Large and expensive space science service infrastructures exist around 400 MHz and 2 GHz, which makes sharing with other services generally very difficult and possible only under very specific circumstances. However, some experience supports the existence of compatibility of certain space science applications with terrestrial services operated in the bands around 1250 MHz, just above 3 and 5 GHz, around 8.5 and 9.5 GHz, and in the 10, 13, 17, 24, 35 and 95 GHz bands. But further studies are required for other applications in these or in extended bands before final decisions can be taken.

WRC-95 adopted Resolution 531 which governs the details of the extensive review of Appendices 30 and 30A and the downlink and uplink Plans for Regions 1 and 3 for the broadcasting-satellite service contained in those Plans. The results of the review will be considered by WRC-97. In line with the instructions given in this Resolution, planning exercises were conducted by BR with the cooperation of administrations and the Radiocommunication Sector (ITU–R). In a first step, a merged file was developed comprising the up-to-date data of both the feeder-link and the downlink path of both Plans. In a second step, administrations of new countries were requested to provide their beam requirements and associated test points, following which two planning exercises were carried out using the planning principles of Resolution 531. The results of these exercises are still subject to review. The third step, which has not been implemented fully, consists of undertaking a first trial run to establish a new Plan, taking into account, as far as possible, all requests for Plan modification submitted to date.

Details of the implementation of the three steps will be submitted to WRC-97 for final decisions. Significant difficulties were identified relating to differences in the principles applied in Regions 1 and 3 and in Region 2 concerning the relationship between the Plans and the other services. A decision on the assumptions and resolution of the differences will still require significant effort before and during WRC-97.

In order to cope with the problems embedded in the agenda and highlighted in this article, discussions on an appropriate conference structure were triggered very early in order to allow the Secretary-General, Pekka Tarjanne, with the assistance of the Director of BR, to make the necessary administrative arrangements for this world event. The Conference will then decide on how it wishes to organize itself and on the Chairmen and Vice-Chairmen to serve it and the committees it will certainly establish. Extensive consultations so far have indicated that apart from the Statutory Committees (Steering, Credentials, Budget control and Editorial) two Substantive Committees will be proposed: a Committee 4 on "regulatory and associated issues" and a Committee 5 on "allocations and associated issues". In addition, two Working Groups of the Plenary might be proposed: one charged in principle with the development of draft and preliminary agendas for WRC-99 and WRC-01 and the other with the maritime and aeronautical issues referred to in this article. The two principal committees, Committees 4 and 5, are foreseen to have three Working Groups each. Working Group 4A could deal with issues consequential to the efforts to simplify the Radio Regulations and with Resolution 18 (Kyoto, 1994) on the review of the frequency coordination and planning framework for satellite networks. Working Group 4B could handle HFBC and related matters and Working Group 4C could deal with Appendices 30 and 30A. Working Group 5A could handle the allocation matters related to the space science services, Working Group 5B could review the provisions related to the MSS and FSS and Working Group 5C could handle remaining issues like wind profilers, high-density fixed services and spurious emissions.

The Secretary-General is suggesting that the Chairman of WRC-97 be offered to Roger Smith from Australia. The Chairmen of Committees 4 and 5 would most likely be designated for persons from Regions 1 and 2. The conference officers thus constituted will try to achieve optimum results and efficiency while respecting the CHF 3.7 million budget set aside for WRC-97 by the ITU Council.

Some of the follow-up activities after WRC-97 may concern subjects such as the new system for managing HFBC or digital HFBC, possible further refinement of the Plans in Appendices 30 and 30A and the related procedures as well as any follow-up of decisions in the context of Resolution 18. Finally, based on the simplified procedures in the new Radio Regulations which will enter into force on 1 June 1998, the Rules of Procedure will have to be revised by the RRB, and BR will have to develop drafts for such revision in a timely manner. But that may be looking too far ahead. The immediate challenge for everyone is finalizing their preparations for WRC-97.

This text is an extract from ITU News 8/97