Backgrounder

Radiocommunications is currently the fastest growing segment of the international telecommunications market. With an ever-expanding range of new applications, from mobile telephony and data messaging to wireless computer networking, global mobile personal communications by satellite (GMPCS), environmental monitoring systems and subscriber-based satellite television and broadcasting systems, the demand for radio frequency spectrum – or ‘bands’ dedicated to these services, usually expressed in MHz or GHz – is growing at an enormous rate.

However, the radio frequency spectrum, although reusable, is a finite natural resource which is already heavily used by some 40 services. Add to this the fact that some bands are unsuitable, for technical or economic reasons, for use by certain systems, and the problem of congestion becomes clear.

World Radiocommunication Conferences are bi-annual international meetings held by the International Telecommunication Union, at which internationally binding treaties on the use of the radio frequency spectrum are adopted. All Member States of the ITU (currently 188 countries) have the right to attend, and private organizations are able to participate through representation on these national delegations. During the WRC 97’s four-week programme some 2,000 delegates will debate a wide range of issues which, although often highly technical, will have enormous ramifications for the way radiocommunications systems develop in the future.

The agenda for each WRC is prepared well in advance. The general scope of the programme is determined four years before the conference itself, then fine-tuned by the WRC that precedes it and adopted by the ITU Council. The ITU Radiocommunication Study Groups and other components of the Radiocommunication Sector are then charged with preparing the groundwork for each issue under consideration by the conference. A Conference Preparatory Meeting collects submissions from these groups and prepares a comprehensive report which outlines in detail the matters under consideration.

One of the main tasks of WRC-95 was the simplification of the Radio Regulations, the internationally-binding treaty on the use of radiocommunications. This question has been under study since the adoption of Resolution 8 at the Nice Plenipotentiary Conference in 1989, which established a Voluntary Groups of Experts to consider ways of making the Radio Regulations easier to use. WRC-97 is expected to conclude the process, and will examine and review some of the modifications, with a view to eliminating any inconsistencies before the revised regulations come into force on June 1, 1998.

The use of the HF bands for broadcasting has been the subject of debate for some 50 years. In 1984, a World Administrative Radio Conference decided on a new method based on planning and consultation procedures. This revised process was considered necessary because of an unsatisfactory situation arising from the imbalance between supply and demand in the part of the spectrum dedicated to HF broadcasting (HFBC). However, simulations to test the new procedures, carried out in the three year period prior to the 1987 Conference (which was to adopt the plan), proved unsatisfactory to the vast majority of delegations who felt that the resulting plan would not satisfy their requirements. As a result, in 1995, the WRC decided to again review the planning system on the basis of studies which were undertaken by the experts of the radiocommunication study groups and requested WRC 97 to consider the new system.

This lengthy review process should be concluded at WRC-97, when it is hoped that a solution can finally be found which will satisfy the requirements of all telecommunications administrations. The preparatory work for this year’s WRC has developed a flexible procedure for co-ordination of broadcasting systems, which provides for co-ordination directly through administrations or broadcasters, or in regional or interregional meetings. Should the WRC-97 decide to accept the new procedure, all that would remain would be to prepare an appropriate regulatory text to cover the introduction of single-sideband transmissions and other techniques which were subject to the completion of the planning system in the HFBC bands.

The conference will examine the need to overhaul a number of operational provisions for the maritime mobile and maritime mobile satellite services and corresponding aeronautical applications, to take into account the full-scale implementation of Global Maritime Distress and Safety Systems (GMDSS), which will come into effect on 1 February 1999. Special procedures need to be developed in a number of areas, including: communication between GMDSS-equipped ships and those which do not have the new system; the use of ship information by search and rescue operations; calling procedures; licensing, and the conditions which need to be met in order to issue an operator certificate. The conference will also look at ways of reducing congestion on calling and port working channels, using methods such as reduced channel spacing or new digital techniques.

In addition, there is a need for more frequencies in the aeronautical mobile service to reflect evolution in the technologies used in that field. Until now, the required spectrum has not been able to be released because of sharing problems with other services in the same bands (VHF), such as broadcasting. WRC-97 will attempt to improve the use of frequency for maritime and aeronautical safety and navigation services, for which freedom from harmful interference is of the utmost importance.

This year’s WRC should again see much interest in frequency allocations for the mobile satellite and fixed satellite services, including Global Mobile Personal Communications by Satellite systems (GMPCS).

The rapid development of new Low Earth Orbit (LEO), Medium Earth Orbit (MEO) and Highly Elliptical Orbit (HEO) satellite systems is taking place in a very congested part of the spectrum. To become fully operational, these systems will be looking to gain spectrum for ‘feeder’ links – that is, earth-to-satellite links for up- and down-loading information – in the 5/7GHz, 15/19GHz and 19/29GHz bands. Satisfying the large demand from the many operators planning LEO, MEO and HEO systems will be one of the conference’s most important challenges.

For GMPCS systems operating below 1GHz (in many cases, so-called ‘Little LEO’ systems), delegates will be required to examine different ways of alleviating spectrum overcrowding, including complex frequency-sharing scenarios that would see new systems sharing the airwaves with existing terrestrial and fixed-satellite services. The sharing difficulties with terrestrial services are compounded in many systems by the high number of satellites many of these systems comprise, and the high number of zones over which they operate. Studies already undertaken have shown that interference to conventional systems could mean occasional disruption of service ranging from every 10 hours to every 21 months. The conference will have to decide whether to delay further allocations pending more extensive studies – which would hamper operators and delay the launch of these non-GSO services – or whether the level or possibility of interference would be low enough to allow for simple fine-tuning once systems have been launched.

For allocations in the L-band around 2 GHz, studies on ways of sharing spectrum have examined band segmentation, separation distances, enhanced antenna design and operational arrangements, but have met with only limited success. The main problem in providing further allocations to the mobile satellite systems in this band is the potential interference to the large number of terrestrial services already occupying this part of the spectrum, in particular terrestrial mobile systems and terrestrial fixed services. In the case of terrestrial fixed services, this issue is of particular concern to African countries, many of which still use the terrestrial fixed satellite service as a key element of their universal service provisions for basic telecommunications. Countries within the Arab region are also concerned about possible extension to the bands allocated to the MSS because of the need to protect the existing and planned terrestrial fixed services.

Nevertheless, it is generally accepted that a worldwide allocation for the mobile satellite service is necessary in order to support global roaming capabilities for the third generation mobile systems currently under development within the scope of the IMT-2000 project. All in all, there is sure to be a great deal of vigorous debate over whether to increase allocations or maintain the status quo.

Debate promises to be intense on the issue of sharing between geostationary fixed satellite systems (such as satellites providing voice and data telecommunications services between two fixed points, which currently represent most of the world’s telecommunications traffic) and non-geostationary mobile satellite systems (such as many planned global mobile telephony systems operating in bands around 20GHz and 30GHz). Adaptive power control, high gain antennas, geographic isolation between earth stations, satellite and site diversity and sophisticated traffic management systems have all been proposed as methods of mitigating the effects of interference between the different systems which want the right to use these frequency bands.

Related to this issue is the need to adopt regulatory provisions for new broadband systems operating in low earth orbits. This new breed of system, the best-known of which are currently the Bill Gates/Craig McCaw-backed Teledesic project, Alcatel’s SkyBridge and Motorola’s Celestri, will provide a fixed-satellite service but will use non-geostationary constellations of satellites. At present, there is concern that the technical parameters of some systems might lead to their de facto monopoly of the limited spectrum available.

In defining the regulations needed to prevent such a scenario, proponents of non-GSO FSS systems will attempt to push for provisions that will not unduly hamper their plans. Some take the view that more spectrum for these kinds of broadband systems would mean a better chance of fair competition between systems. The WRC will try to achieve a balance between clearing the path for healthy, equitable growth of these systems and protecting geostationary systems. One proposed way of achieving this would be to limit the emission power of LEO satellites, but to date this has been opposed by key players. Some delegations are of the opinion that spectrum is too limited and valuable to consider increasing allocations for broadband systems, and that technical solutions are already built in the systems to allow for the sharing between GSO/FSS and non-GSO/FSS on a non-interference basis.

The conference will also likely see vigorous debate over Radio Regulation S22.2, which relates to issues of interference between geostationary fixed service satellite systems and mobile satellite systems. This regulation, put in place by WRC-95, currently states that in cases of interference, a fixed service application has priority over a mobile service application. Many delegations will be pushing to change this regulation so as not to disadvantage future satellite service operators, to whom the ability to offer reliable and consistent service will be paramount in the race to attract customers. Other delegations who may be more reliant on geostationary services will naturally be looking to protect the interests of the GSO operators. All agree, though, that any measure imposed should not be so restrictive on either type of system (GSO FSS and non-GSO MSS) as to inhibit future innovation and development.

All in all, as with WRC-95, satellite system allocations are likely to be the most hotly contested agenda items. The many satellite operators will lobby hard, via their national delegations, for the space they need to get these costly systems up and running as quickly as possible in order to win the market share needed to make their systems viable. It seems unlikely that WRC-97 will be able to satisfy all the requests for space; the most likely outcome will be a compromise that will try to accommodate the needs of planned new systems while protecting the interests of existing users.

Space science services cover active and passive sensing systems incorporated into satellite systems. They are used primarily for meteorology, climatic studies, the production of satellite images such as weather maps, and other kinds of environmental monitoring.

These systems can only share with other services under very specific circumstances. For example, space science services are not able to share in situations where there is a high density of stations from the fixed service. As well, in the 2 GHz band, which is used for some space science services, there are already many other services in addition to demand for more by the Mobile Satellite Service.

The conference will look at the possibility of extending space science services into other bands where it would be possible to establish common worldwide primary allocations without sharing problems in bands currently housing terrestrial science services.

For satellite systems to operate effectively, they need to be ‘co-ordinated’ – that is, their operating frequencies and orbital positions need to be checked before they can be put into service, to ensure that they are not going to cause interference to other satellites already in place. This co-ordination is the responsibility of the ITU, which receives all requests for new satellite systems, and performs the checking of operational parameters and publishes a Master International Frequency Register of all satellites currently in place.

For some time, the coordination of satellite networks has been problematic, due to the rapidly growing demand for satellite-based services. There is strong competition in the marketplace between operators, who are keen to move quickly to get a foothold in emerging new markets, and who are pushing for faster co-ordination procedures and notification of satellite positional allocations. In regions with a high concentration of planned and existing satellites, the congestion and difficulties in obtaining coordination agreements are such that some operators are bringing systems into use, or repositioning existing satellites, without proper co-ordination. In the regions with highly ‘valuable’ orbital positions – such as those covering lucrative markets – real conflicts are beginning to emerge. At present, there is no formal means of resolving such disputes.

Another consequence of this problem of co-ordination is the issue of so-called ‘paper satellites’. These are satellites systems which have been notified to the ITU and co-ordinated, but which in reality have never been launched. Paper satellites have largely come about because of desire to ‘hoard’ satellite slots for future use.

These types of problems were recognized by the ITU’s 1994 Kyoto Plenipotentiary Conference, which adopted Resolution 18 calling for a review of issues regarding international satellite network co-ordination and planning.

WRC-97 will examine a number of proposed solutions to these complex problems. Proposals for amendments to the system include a provision that only applications for satellite systems which are definitively planned to be put into operation should be submitted. To ensure this principle is adhered to, measures called ‘due diligence’ have been put forward. Under the principle of due diligence, the ITU would require satellite operators to regularly provide information on the implementation status of any planned system, with failure to comply resulting in loss of the priority rights of that system to certain frequencies and orbital positions.

The new proposals also recommend that operators be required to pay a filing fee for initial applications, a registration fee covering any system recorded in the Master International Frequency Register, and a deposit when requesting space for a new satellite system, which would be refundable when that system can be demonstrated to have come into service.

The proposals, which cover 17 Recommendations, also aim to prevent administrations filing for multiple satellite positions at once, a practice currently in use to increase the possibility of successfully completing coordination of one of these positions. Because the orbital position and related proposed frequencies are in effect ‘blocked’ on a first-come first-served basis while the coordination process in under way (which takes between 6 to 9 years), administrations ‘play it safe’ by making multiple satellite filings. While perhaps understandable, this practice limits the options for newcomers. Under the proposed new arrangements, administrations would be required to submit one filing, which gives details of possible alternative positions should the first not prove feasible. This approach is expected to meet some opposition from those who fear that these new arrangements would simply prompt administrations to submit several alternative positions, even if they had not intended to submit multiple filings under the current system.

Other proposed changes to the regulations governing satellite orbital positions include the regulatory time-frames under which satellite systems are required to be put into service, the agreed operation lifetimes of satellite assignments, enhanced provisions for participation of satellite operators in the co-ordination process, provisions for the use of databases to track satellite use, a guarantee of equitable access for all applicants for satellite positions, improvements in the efficiency of use of spectrum and orbital resources, and a mechanism for dispute resolution which would empower the ITU to settle disputes arising from unsuccessful satellite coordination exercises.

This year’s WRC will look at the possibility of creating a single global frequency allocation for use in direct television broadcasting applications. This would enable broadcasters wanting to offer service on a worldwide basis to broadcast on the same frequency in all countries which agree to accept their service, greatly simplifying worldwide frequency co-ordination as well as the broadcaster’s own technical and marketing operations.

It is also proposed to change the ‘Beam Group’ concept, which is currently used by regions which are culturally, linguistically or otherwise linked in addition to national positions. Many feel this arrangement is an inefficient use of the orbit/spectrum, because two or more positions are used to provide the same number of channels. This in turn can lead to the ‘warehousing’ of orbital positions, since all positions must be protected from interference, whether they are in use or not.

A final issue deals with the use of the fixed-satellite service for direct-to-home broadcasting. Some delegations advocate that such use should be completely avoided, or at least be subjected to the prior agreement of countries which would be receiving the signals of the satellite. The concerns in this area mainly relate to the complex issues of national sovereignty.

1–2 GHz	L Band
2–4 GHz	S Band
4–8 GHz	C Band
8–12 GHz	X Band
12–18 GHz	Ku Band
18–27 GHz	K Band
27–40 GHz	Ka Band
40–75 GHz	V Band
75–110 GHz	W Band
110–300 GHz	mm Band
300–3000 GHz	u mm Band

The Main Issues of WRC 97