With this year�s World Radiocommunication Conference (WRC-2000) just a few weeks away, staff throughout the ITU secretariat are now working hard to complete the extensive preparations needed to support a conference which has become one of the Union�s most complex and onerous events.

This year�s conference is being held in Istanbul, at the kind invitation of the Turkish Government. Running a full four weeks, from May 8 - June 2, the event will require the services of nearly 300 staff including interpreters and translators, who will work around the clock to prepare and distribute an estimated total of 30 million pages of documentation to the expected 2,500 international delegates representing both governments and private sector interests.

With the huge surge in popularity of Radiocommunication services over the last 10 years, the WRC has achieved a reputation as a gruelling event characterized by late night sessions, forceful debates, and intense negotiating and lobbying.

When drawing up proposals for ever-longer agendas for following conferences, each WRC is faced with a tough choice: either propose an item for the agenda of the next conference and risk overloading that conference to the point where it is unable to deliver vital decisions needed in other areas, or propose to delay the item until the following conference four to six years hence, and risk delaying development and deployment of potentially beneficial services. It�s a difficult balancing act, but the Radiocommunication Sector continues to try its best to speed the process through extensive pre-conference preparations including encouraging telecommunication organizations to convene regional and inter-regional meetings to harmonize positions to the maximum extent possible prior to the Conference.

At each conference, delegates debate the use of frequency bands for a large number of services, from mobile services and low earth orbit satellite systems to satellite broadcasting, aeronautical and maritime navigation, as well as amateur, radioastronomy, earth exploration and deep space research. Some proposals to WRC-2000 concern the need for additional spectrum to facilitate expansion of existing services and to foster development of brand-new technologies and applications. Other proposals relate to regulatory procedures and the equitable use of spectrum. As some parts of the spectrum become intensively used, the conference is required to ensure that all users can share safely without harmful interference.

At WRC-2000, the agenda items that are likely to attract most attention can be outlined briefly as follows:

With third generation (3G) mobile systems based on ITU�s IMT-2000 standard due to come into service very soon in different countries, most delegations are working to find ways to increase spectrum allocations for 3G services in light of the expected rapid growth of large-bandwidth mobile data services.

The estimation of a minimum requirement of about 230 MHz was the basis for the WARC-92 decision to identify spectrum in the bands (1 885-2 025 MHz and 2 110-2 200 MHz). At the time, voice services were considered to be the major source of traffic, and only low data rate services were additionally considered. Usage of the mobile services has increased substantially since 1992 and, along with the growing demand for megabit data rates, have overtaken the estimations of that time.

WRC-2000 will consider proposals for satisfying a forecast need for an additional 160MHz beyond the spectrum identified in 1992 and beyond the spectrum used in the three Regions for first and second-generation mobile systems. A number of candidate bands have been identified each offering advantages for some and drawbacks for others.

While a global, harmonized additional allocation is generally supported, it has been very difficult to find bands that would draw consensus because of their current use by other services such as analogue and digital TV, digital audio broadcasting, aeronautical radionavigation service, meteorological radars, fixed wireless access and more. A lack of consensus would not prevent countries from making mobile spectrum available for IMT-2000 on a national basis, but this would result in higher handset prices for third generation systems because of the need to incorporate more complex circuitry to support international roaming across different frequency bands.

Intense private sector interest in the potential of satellite systems to deliver mobile voice and broadband data services has resulted in a large number of proposed new systems and services from non-geostationary satellites. To avoid possible interference with existing or planned geostationary satellites operating in the same frequency bands (10-18GHz and 20-30GHz), WRC-97 established provisional power limits for these non-geostationary systems. WRC-97 also directed the ITU-R to undertake studies in the intervening period until the next WRC, to determine whether sharing was feasible.

This year�s conference will examine the results of those studies, which seem favourable to the concept of shared use of the bands in question by non-GSO and GSO systems of the Fixed Satellite Service and the Broadcasting-Satellite Service. The agreement reached during the Conference Preparatory Meeting of last November, based on the ITU-R studies, should facilitate a final resolution of this issue at WRC-2000.

One of the most contentious issues at the 1997 conference, this issue promises to be just as difficult this time.

Under the existing BSS plan adopted by WRC-97 for Regions 1 and 3 (i.e. everywhere other than the Americas) which has roots back to 1977, each country enjoys a certain capacity and the use of that planned capacity is restricted to national services. However, for small countries or for countries with a small population, the use of that capacity may prove to be uneconomical. One of the compromises reached at WRC-97 was to request the ITU-R to study ways in which the capacity for each country could be increased. These studies have shown that an increase in capacity compared with the plan adopted by WRC-97 is possible.

At WRC-2000, some delegations will advocate adoption by the Conference of a new plan based upon the studies in ITU-R while others will favour further studies to be conducted before adopting of a revised plan at a subsequent conference.

Re-planning is a very complex matter with many inter-related aspects such as the level of constraints imposed for the protection of existing and future assignments in both space and terrestrial services, the allocations to which are different in the different regions, the need to carry out the re-planning on the basis of fully digital channels while accommodating existing analogue systems and the interest in accommodating sub-regional systems in a Plan originally engineered on the basis of a national coverage of a fixed capacity per country.

In addition to the technical challenges, the question of BSS re-planning has implications which touch on issues of national sovereignty.

New High Density Fixed Service (HDFS) technology has great potential to provide a wide range of broadband point-to-point and point-to-multipoint services. These systems can support high-speed, wireless connections at up to 155Mbps, making them ideally suited to linking geographically diverse sites like corporate branch offices or hospital and university campuses, as well as to providing automated services like meter readings for gas or water services.

Other applications include the deployment of mobile network infrastructure for existing and new systems or fixed wireless access. HDFS also can potentially accommodate new telecommunication operators in competitive markets, provide alternate technologies for upgrade of existing telephone infrastructure or for greater access and service choices for residential and commercial users for telephony, data and multimedia services

Highly accurate satellite positioning data is becoming increasingly important for a wide range of activities, from navigation on land, in the air, at sea and in outer space to national security to new consumer-oriented position determination applications. There are over eight million Radionavigation-Satellite Service (RNSS) receivers in use today for a wide range of applications, including safety-of-life, critical navigation on land, at sea, and in the air.

Today, the Global Navigation Satellite System (GNSS) consists of the United States Global Positioning System (GPS), the Russian Federation Global Navigation Satellite System (GLONASS), space and ground-based augmentation systems, and pseudo-satellites (pseudolites).

New generations of GPS and GLONASS satellites are being designed and new RNSS systems proposed including Europe�s Galileo. These second-generation global navigation satellite systems promise to provide even better satellite radionavigation facilities.

Such second-generation systems are however competing for frequencies in a part of the spectrum already heavily used.

The conference will also be asked to look at sharing proposals for bands designated for use by so-called High Altitude Platforms (HAPs). These new projects aim to provide wide-area fixed wireless service from balloon-like devices located in the Earth�s stratosphere.

There is also concern over the growing impact of mobile and other transmitting technologies on radioastronomy and other passive services. These passive services are concerned about interference from satellite and terrestrial based transmitters, and are seeking "quiet zones" in the spectrum which would be completely free of other radio transmissions.

Finally, the possible allocation to the Mobile-Satellite Service in the bands 1 559-1 567 MHz currently exclusively allocated to aeronautical and maritime navigation � a contentious issue at WRC-97 � has been the subject of studies by the ITU-R to determine the suitability of sharing between these services. All studies agree that, at the very least, mobile-satellite systems would not only preclude the introduction of new radionavigation satellite applications in the band 1 559-1 567 MHz but could have an adverse impact on the evolution of GPS by preventing the use of the lower part of the existing GPS frequency assignment. These studies should therefore help to resolve this issue at WRC-2000.