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Sharing the Spectrum: a matter of international negotiations

Radio waves are currently defined as electromagnetic waves of frequency arbitrarily lower than 3000 GHz, which are propagated in space without artificial guide. Such waves have been known to exist since the early 19th century, and much of the theoretical work to understand their nature was undertaken by James Clark Maxwell, a Scottish physicist, David Edward Hughes, an Anglo-American physicist, and Heinrich Rudolf Hertz, a German physicist.

Experiments designed to find ways of harnessing the potential of radio waves to carry information were carried out towards the end of the 19th century and the beginning of the 20th century by many physicists and engineers, the most well-known of them being Guglielmo Marconi, Jagadis Chunder Bose and Alexander Stepanovitch Popoff.

The commercial exploitation of radio waves for sending signals at long distances (beyond the line-of-sight or beyond normal human hearing) began in 1897 when Marconi established his Wireless Telegraph and Signal Company Ltd. in London.

Accordingly, nine countries met in Berlin in 1903 to undertake preliminary studies for the international regulation of radiocommunication. The first radio conference, which drew up what are presently known as the Radio Regulations, was held in that same town in 1906. Today, the Regulations cover use of the frequency bands between 9 kHz and 400 GHz, and have increased in volume and complexity at each radio conference since this date.

With the increase in the number of applications using radio frequencies, as well as technical advances which made it possible to use the radio frequency spectrum more extensively for commercial purposes, the Radio Regulations covered wider and wider spectrum and included more and more radio services. This gave rise to the idea of an internationally agreed Table of Frequency Allocations, which was included in the Radio Regulations in 1912.

The fact that the radio frequency spectrum below 30MHz provided the means for all long-distance radio-based communications considerably increased the need to introduce strict discipline in the use of that part of the spectrum. Therefore, a group of countries met in Moscow in 1946 and took certain decisions which were subsequently expanded upon and endorsed at the ITU Administrative Radio Conference and the Plenipotentiary Conference held in Atlantic City in 1947.

One of these decisions was to make, from 1947, the Table of Frequency Allocations contained in the Radio Regulations compulsory for all users.

The Atlantic City Radio Conference developed a structure for the management of the radio frequency spectrum based on four fundamental principles: allocation of spectrum, planning, coordination/agreements and notification (see box, page 3).

The Radio Regulations based on these principles have undergone two complete revisions (1959 and 1979) and many partial revisions since 1947. However, the basic principles on which the initial Regulations were based have remained essentially the same.

The Radio Regulations have the force of an international treaty and must form the minimum essential element of national law of each Member country in respect of the use of radiocommunications.

To understand the Radio Regulations, it is necessary to have a broad familiarity with their basic elements, particularly those relating to international management of the use of the radio frequency spectrum and the geostationary-satellite orbit. An explanation of the essential terms is outlined below:

The Role of the ITU

Ever since the advent of wireless communication, one of the major responsibilities of the ITU has been to regulate the use of radio frequencies. The work that responsibility entails is of direct concern to the public at large, although most people are seldom aware of it, given the intangibility of radio frequencies. The work of the ITU is vital for such services as mobile telephony, microwave radio-relay, satellite imaging, television broadcasting, AM, FM and shortwave radio, maritime or aeronautical communications, wireless computing, and a wide variety of other kinds of radio-based networks such as those used by the police, ambulance service, taxis, and so on.

Regulating Spectrum Use

Currently, their are some 40 services different services competing for frequency allocation, covering a variety of uses from terrestrial to satellite, fixed to mobile, and radar to research. The diverse demands of these services have been taken into account and accommodated in the Regulations, which carry the status of an international treaty and are binding on ITU Member States . In their present form, the Radio Regulations run to more than 2,500 pages.

The usable range of spectrum is actually sliced up into small portions of varying widths, depending on the types of use envisaged. Those sections are referred to as 'frequency bands' and allocated in a Table of Frequency Allocations to different radiocommunication services on an exclusive or shared basis. Changes to that Table (or for that matter to the Radio Regulations of which the Table is a part) can only be made by a World Radiocommunication Conference, and can be effected only on the basis of decisions taken by consensus, or vote if necessary, following negotiations among national delegations.

The existence of internationally established plans and procedures facilitate the introduction of new radiocommunication systems, in so far as they serve to guarantee the stability of the designs on which such systems are planned.

For a satellite system, some six years generally elapse between its planning and implementation. This lead time includes the time needed for the construction and launch of the satellite. If, during that period, the technical parameters of the satellite (for example, transmit power, antenna characteristics, coverage areas, foot prints, elevation angles, modulation characteristics, etc.) need to be changed, serious and costly modifications could be necessary, such as additional capital costs and delays in bringing the system into operation.

For similar reasons, other kinds of wireless equipment such as communication equipment for use on-board aircraft or ships is also manufactured to conform to the relevant technical characteristics developed in the study groups of the ITU’s Radiocommunication Sector (ITU-R) and approved by ITU Radiocommunication Assemblies .

The economic and industrial implications of decisions concerning use of the radio frequency spectrum are invariably considered in the negotiations carried out at ITU conferences. The Union’s conferences aim to strike the right balance between the need to keep pace with technological change and the need to ensure a degree of system stability in the application of new technology.

How are frequencies allocated?

The ITU Member countries have three instruments at their disposal as a means of sharing frequencies at the international level: the Table of Frequency Allocations; assignment and allotment plans; and coordination procedures (as prescribed in the Radio Regulations).

Table of Frequency Allocations

Frequency bands are allocated to the various radiocommunication services on either an exclusive or a shared basis. There are three categories of service: primary, secondary and permitted. Such allocations may be made world-wide or be limited a region of the world.

The Table, and the Radio Regulations of which it forms part, can be amended only by a World Radio communication Conference to which all Member States of the Union are invited. Amendments are introduced following negotiations between the national delegations aimed at reconciling the demand for frequencies with the capacity of the spectrum.

If a country or group of countries request the use of a band by a service different from that on which the rest of the world has agreed, such use may, if there is consensus to this effect, be included in the Table in the form of a footnote or authorized by the application of a procedure introduced in the Regulations whereby the countries concerned secure, prior to the planned use of the frequencies in this band, the agreement of other countries which may be affected.

A page of the Table of Frequency Allocations is reproduced on page 7 to illustrate the complexity of regulation. As it clearly demonstrates, in the band 138 – 148 MHz, each of the three regions of the world has decided to use frequencies for different services. In addition, exceptions have been accepted as indicated in the additional allocations in the footnote.

In Region 2, for instance, the frequencies between 138 and 143.6 MHz are shared between the fixed, mobile, radiolocation and space research services in the following order of priority: first, the fixed, mobile and radiolocation services on a primary basis, then space research on a secondary basis (i.e., without right of protection against signals from stations in the primary services category but with right of protection against signals from other stations in the secondary services category). The same frequencies are allocated differently in Regions 1 and 3. Since a similar scenario applies to all frequencies between 9 kHz and 400 GHz, it is an extremely difficult and complex matter to negotiate amendments to the Table and manage their application.

Plans

Besides the Table of Frequency Allocations, conferences adopt assignment or, if appropriate, allotment plans for certain services in specified frequency bands in which transmission and reception are not necessarily confined to the territory of a given country. On the basis of the requirements expressed by each country, assignment plans allocate frequencies for each station in a given service; allotment plans grant to each country frequencies intended for use by a given service, frequencies which the country then assigns to the stations within its jurisdiction according to their needs.

When such plans are established, delegations study and adopt technical criteria, applicable planning parameters and criteria for sharing with other services if appropriate. They also have to assess all the risks of harmful interference and establish implementation procedures before assigning or allotting frequencies. Such plans must always comply with the Table of Frequency Allocations.

Coordination

When plans are not established, procedures are developed for international coordination to ensure that a country planning to use a given frequency obtains the agreement of all countries which may be affected by its use.

The Radiocommunication Bureau must be notified of any use of frequencies that might cause interference outside the territory of the country in which the relevant station is located or if the country wishes to have international recognition for its usage of frequencies.

The Register in which all frequencies notified to the Bureau are registered now contains some 1 601 541assignments, each one of which must be able to be used without causing interference to any other.

The notification of frequency assignments, the examination of notices and the recording of assignments in the Register constitute an ongoing process which the Bureau carries out throughout the year; once a week the Bureau publishes for all Member countries all the information concerning the notices received and the results of their processing, leading either to an entry in the Register or the return of the notice to the notifying administration. The Bureau receives some 1,250 new notices every week!

Frequency Registration

One of the primary responsibilities of the Radiocommunication Bureau concerns the examination of notices, from administrations, of new frequency assignments as well as changes to frequency assignments, and their entry in the Master Register following the application of any co-ordination procedures between Members of the Union, in accordance with the relevant provisions of the Radio Regulations.

Procedures governing notification and registration of frequency assignments in the Master International Frequency Register may be broadly subdivided into the acts of co-ordination, notification, examination, and registration. The intent of these procedures is in effect to ensure a co-ordinated approach by administrations to the use of spectrum , thus reducing the probability of harmful interference.

If all Bureau’s findings are favorable, the particulars of the assignment are entered in the Master Register, accompanied by all relevant remarks, that establish the legal status of and confer international recognition to the assignment, as is indeed the case with other assignments (existing or future) similarly recorded.

If some of the Bureau’s findings are unfavourable, the notice is returned to the notifying administration with a view to modifying the characteristics of the station in such a way as to obviate the probable harmful interference. The administration may alternatively decide to use the frequency on a non-interference basis, in which case the frequency assignment is recorded in Master Register with the indication that the administration will not cause interference to conforming assignments.

The Future Role of the ITU

Throughout its history, the ITU has demonstrated a remarkable capacity to adapt. None of its Member States has ever resigned, and the ITU itself has survived two world wars during which its Secretariat has continued to function. Now, as during the previous 133 years of uninterrupted existence, the Union continues to play a key role in the global development of telecommunications. It remains the corner stone of the world telecommunications industry, bringing governments, private companies and other interested parties together to forge new communications systems, and new means of managing them. The manner in which the Union carries out its mission is being constantly revised in the light of today’s rapidly-changing communications environment; but the objectives the Union set itself 133 years ago – that is, to work to ensure that as many of the world’s people as possible have fair and equitable access to telecommunications – are today as important as ever.