On behalf of CEPT, the Conference on European Posts and Telecommunications, the European Radiocommunications Office has completed the first Detailed Spectrum Investigation into the use of radio frequencies in the microwave or millimetric spectrum between 3.4GHz and 105GHz. Two other bands, 29.7MHz to 960MHz and 960MHz to 3.4GHz, will subsequently be studied. The Detailed Spectrum Investigation’s recommendations have been combined in a first proposal for a European Table of Frequency Allocations which aims to standardise the use of frequencies across CEPT countries where possible. Implementation is hoped for by around June 2008. The millimetric frequency band includes such services as satellite television, fixed radio links, the connection of parabolic dishes on high towers, radar, satellite transmissions and radio astronomy. One aim was to substantiate or refute the claim that there are not enough frequencies to satisfy demands, as well as to try and determine the direction of future plans. The European Radiocommunications Office is seeking contributions from the public to the document, which should be delivered by June 15 – with a final cut-off date of September 24. The Detailed Spectrum Investigation process is intended to ensure that everyone should derive maximum benefit from the limited radio spectrum resource.
Operational needs
It aims to take account of the operational needs of existing users, obligations that international treaties and organisations impose, the impact of technological developments and the availability of resources to meet recommendations and implement changes. Bodies that have particular input to and effect on issues of European spectrum management include the European Commission, which is taking an increasingly active interest in telecommunications and has identified two major tasks ahead for member states: the liberalisation of telecommunications services and the separation of regulatory and operational functions. It has also adopted a set of Directives in order to harmonise legislation and conditions for access to the network. Other involved bodies include European Telecommunications Standards Institute, the International Telecommunications Union, the World Administrative Radio Conference, the military community, and associations including those for the electronics, civil aviation and maritime industries. Even though the data derived from the Detailed Spectrum Investigation does not constitute a detailed analysis of the European situation, it is possible to draw some general conclusions. Although there is not much use of frequencies above 20GHz, below 15GHz there is intensive use of traditional fixed service frequency bands. Fibre is the preferred medium for high capacity circuits for many operators and may become the medium of choice for primary transmission circuits, given time. No large scale expansion in high capacity radio relay equipment is foreseen, despite the re-engineering of networks to give digital operation. On the other hand, radio is still used for diversity of routing or for emergency circuits, particularly in tricky terrain or earthquake-prone zones where optical fibre circuits might fracture. The provision of cellular links by independent operators is an increasing trend for radio and there is some evidence that companies would like to set up their own private networks. Any competitive networks set up might produce an increase in demand as a result of having stimulated new requirements. Although the need for fixed radio relay systems seems likely to remain at current levels in the foreseeable future, any diminution in spectrum availability will have to be compensated for. This will entail enhancing frequency management processes and increasing use of frequencies above 20GHz. The radio spectrum is being used in a variety of countries for ancillary broadcasting in the shape of outside broadcasts and electronic news gathering. Satellite TV news gathering, which represents a likely area for substantial development, often uses the fixed satellite service band.
By Julia King
The bands used for this type of application differ considerably from country to country, although spectrum around 7.5GHz is common. Valuable frequency band should not be reserved exclusively for use by outside broadcast units on the offchance that an incident may occur, however, the European Radiocommunications Office feels. On the other hand, there should be harmonised bands for temporary unidirectional fixed and mobile links – at least in the short term. In the longer term, spectrum has been identified in the band 4.4GHz to 5.03GHz and it is thought that military tactical requirements and outside broadcast and news gathering applications could be compatible in such situations. The European Radiocommunications Office also wants to introduce procedures to allow for rapid response to requests for frequency allocation in bands recognised as those used for outside broadcasting or electronic news gathering. Although established network operators are now primarily using optical fibre for high capacity communications links, there is little evidence that the overall amount of spectrum available for fixed service use, in terms either of point to point use or outside broadcasts and electronic news gathering applications, should be reduced. The Detailed Spectrum Investigation team recommends that spectrum should be rearranged in some bands but that any shortfall should be recovered from improved frequency management techniques in other bands. At present, around half of transatlantic telephony traffic is carried via satellite. This percentage is likely to decrease as a result of improvements in cable systems. The Fixed Satellite Service spectrum is also used by Eastern European countries and international satellite consortia. The C and Ku bands, 4GHz to 6GHz and 11GHz to 14GHz respectively, are now heavily used. The deregulation and liberalisation of Earth segment proposed by the European Community would lead to a general increase in spectrum requirements and to a need for simplified co-ordination procedures. An increase of the Fixed Satellite Service band is proposed between 3.5GHz and 3.6GHz while flexibility is called for in the existing bands for Fixed Satellite Service and the Broadcasting Satellite Service, particularly between 11GHz and 12GHz. This band is also likely to be used for services such as narrow band high definition television start-ups using standards such as the ill-favoured HDMAC. Civil mobile systems are at an early stage of development but a low power band has been proposed, centred on 3.455GHz, and consideration has also been given to operation of future land mobile systems around 3.4GHz. There have also been allocations for broadband mobile systems in bands around 40GHz and 60GHz. A variety of other bands have also been proposed. Defence and civil applications already share spectrum to some extent. It is felt that the 7GHz to 8GHz segment, already used extensively by defence authorities, should be kept under review and that an agreement for sharing the 20GHz to 30GHz space allocation should be developed.
Need further study
Bands used by radio determination systems need further study, the Spectrum Investigation has determined. There is a possibility that systems such as radio location systems could share with maritime radio navigation systems, particularly in areas remote from the coast and major inland waterway systems. The Detailed Spectrum Investigation results have been amalgamated into a proposed table of frequency allocations and use. The European Radiocommunications Office notes that sometimes the requirements of different interest groups are in conflict, but it is hoped that the correct balance has been found. The Office suggests an implementation schedule which enables some bands to be introduced rapidly while more problematic ones will take longer. Allocations of large blocks to individual users should be kept to a minimum because of the inflexibility of the allocation process. In some areas of the spectrum, more research is needed to enable more efficient use to be made. To develop strategi
c plans more accurately, the Detailed Spectrum Investigation team considers it wise for CEPT administrations to carry out their own investigation on a national basis. These studies should occur before spectrum is allocated for major new developments in radio communications.
