The radio spectrum is the range of frequencies used for radiocommunication of all types. It is divided into nine bands, usually designated in English symbols (e.g. VLF, LF, MF, HF, VHF, UHF, SHF, EHF).
In ITU terminology, radio services means all types of service using the radio spectrum, not only for straight communication purposes, but also for such things as broadcasting (sound and television), radio astronomy, aeronautical and maritime services, meteorological observations, radionavigation, research and so on.
The Radio Regulations are an international treaty setting out the allocation of frequency bands to different radio services; technical parameters to be respected by radio stations; procedures for the notification and international coordination of specific frequencies assigned to stations by national administrations (frequency assignments); and other procedures and operational provisions. The Radio Regulations are vital to the modern world, for if radio services are to operate efficiently worldwide (no harmful interference), frequency assignments must respect the prescribed allocations , technical requirements and operational procedures. The latest version of the Radio Regulations is the 1998 edition, contained in a four-volume red book. The body of the text is divided in to chapters, articles and provisions; then come the appendices; and lastly the resolutions and recommendations. The official way of referring to a provision is "No. S1.18 of the Radio Regulations" and to an appendix "Appendix 3 of the Radio Regulations", and it is this formulation which should be used in official documents. However, one often sees "S1.18" and "APS4" for short.
Frequency bands (slices of the spectrum) are allocated to different services either worldwide (worldwide allocation) or regionally (regional allocation). To this end, the world is divided into three Regions (Regions 1, 2, 3), defined in the Radio Regulations (No. S5.2).
Each band may be allocated to one or more services, with equal or different rights. There are two categories of service, namely primary and secondary . Band allocations are set out in the Table of Frequency Allocations (Article S5 of the RR). Exceptions (additional or alternative allocations, different categories of service,etc) or restrictions on allocations in the Table, usually geographical in a smaller area than the region (country, group of countries), are covered in "footnotes" (French: "renvoi") to the Table. In ITU terminology (Nos. S1.16-S1.18), frequencies are allocated to services (allocation), assigned to stations (assignmnet) and allotted to areas or countries (allotment).
When a country intends to implement a frequency assignment to a radio station which is liable to affect other countries' stations, the Radio Regulations come into play. The country's telecommunication administration has to follow relevant procedures in the Regulations in order to register the frequency. This serves two purposes, namely: ensuring that the new assignment does not adversely affect other countries' existing or planned assignments; and recording the new assignment so that it enjoys recognition by (and in some cases protection against harmful interference from) subsequent assignmnets. The exact procedure to be followed depends on the precise service and band con cerned, and it is difficult to summerize the situation in one or two paragraphs.What follows must therefore be considered as a gross simplification. The procedures differ significantly, in particular, between space and terrestrial services and between what are known as planned and non-planned bands. Generally speaking, assignments go through some combination of the following steps:
The telecommunication administration wishing to bring an assignment into service (notifying administration) submits all relevant information, including at least the basic characteristics of the assignment, to the ITU (more specifically, the Radiocommunication Bureau).
The Radiocommunication Bureau (BR) publishes the information in its Weekly Circular to inform all other admiinistrations and allow them to react.
The BR examines the proposed assignments from the the point of view of conformity with the Regulations (regulatory examination) and to determine whether it can operate without causing or suffering harmful interference technical examination. The conclusions of the BR's study will take the form of a finding, which may be favourable or unfavourable. In some cases (e.g. incomplete information, notice submitted too early) the notices are returned to the notifying administration without finding.
The administration and the affected administrations communicate with each other in order to iron out any incompatibilities and difficulties (e.g. by changing some of the characteristics, agreeing to certain hours of operation or levels of interference,etc). When the matter is settled, the notifying administration is deemed to have obtained coordination agreement.
Before the administration notifies to the Bureau a frequency assignment in accordance with footnote in the Table of Frequency Allocations which makes reference to Appendix S4, it should obtain agreement of any other administration whose services may be affected.This procedure may be initiated before or at the same time as the application of the provisions of Appendix S9 of the Radio Regulations.
Once all the relevant procedures and agreements have been successfully complet ed and obtained, the BR records the assignmnets in a database called the Master International Frequency Register (MIFR) or Master Register for short. The entry in the register, set out in different columns, includes all the technical and other details pertaining to the assignmnet (frequency, power, date of commencement of operation, etc).
Some bands are covered by what is known as a plan; others are accessible on a first-come-first-served basis.
In the so-called planned bands, access to the spectrum is guaranteed by a priori planning (allotment plan, channelling arrangement,...), normally carried out at a world or regional planning conference. Each administration (country) submits its requirements, technical bases for the plan are established at the conference and a plan is drawn up to "share out" the available spectrum. Procedures are established for the introduction of new assignments or modification of existing ones, contained in an Agreement in conjunction with the Plan. The advantage of this system is that it guarantees equitable access to the spectrum: each country receives an entry to use as and when it is necessary. The drawback is its rigidity, valuable spectrum is tied down, even if it is not in use.
The so-called non-planned bands are filled on a first-come-first-served basis, according to the requisite combination of the procedures described above. The advantage of the procedure lies in its flexibility, making efficient use of the spectrum. However, it makes it more difficult for latecomers to fit in their assignment.
The Radio Regulations, being an international treaty, can only be amended by decision of the signatory states (ITU Members). Thus, they are revised at world radiocommunication conferences (WRC) - formerly called world administrative conferences (WARC) - convened for that purpose.
Sometimes, more detailed guidance is required as to the precise interpretation or application of provisions of the Radio Regulations. To this end, the Radio Regulations Board adopts Rules of Procedure.
The Plenipotentiary Conference (Nice, 1989) noting that the Radio Regulations were rather complex, unwieldy and difficult to apply, resolved that a Voluntary Group of Experts (VGE) be set up to study ways of simplifying them. The results of the VGE's work are set out in the tree-volume "VGE Report". The VGE's recommendations were discussed at WRC-95, with a view to revising the Radio Regulations accordingly.
Revised: April 28, 1999