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A Strategy for the Future Use of the Radio
Spectrum in the UK
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A Strategy for the Future Use of the Radio
Spectrum in the UK
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In the trunk networks there will be a growing demand for spectrum for fixed links as fixed radio access providers and other new public telecommunications operators (PTOs) roll out their networks. An increasing proportion of trunk links will employ Synchronous Digital Hierarchy (SDH) technology. It is envisaged that each new PTO will require a backbone trunk network of some 200 links capable of bit rates of 2x155 Mbit s-1. The Agency intends to meet this demand by:
· taking over management of more of the existing PTOs' spectrum;
· encouraging mature networks onto cable;
· implementing a stringent link length policy.
Local distribution to nodes will need to expand equally and many medium hop links in the higher microwave bands will be required. This could involve upwards of 1000 links per operator with bit- rates of up to 51 Mbit s-1.
Access networks will also become more important for the final link to customers as competition in the local loop increases. Operators have been licensed for:
· rural services (up to ISDN) (2 GHz band);
· residential telephone service (3.4 GHz and 4 GHz bands);
· business service (ISDN and above) (10 GHz band).
The high demand for millimetric links is expected to increase when more mobile operators, including those with future public land mobile telecommunication systems (FPLMTS), seek to interconnect their networks. There is likely to be a number of operators requiring a total of several thousand links in the 25, 38 and 55 GHz bands.
Demand in the 58 GHz uncoordinated band will remain strong as the installation of video security systems linked to central control rooms continues. In addition the 31 GHz band will be used to provide longer video links where these are required. The development of digital systems will make it possible to multiplex several video signals on one radio channel.
The emergence of multimedia services will increase traffic in the microwave and millimetric wave bands to provide similar infrastructures to those required by the personal communication networks (PCN), but with much higher bit rates of 34 Mbit s-1.
A WARC 92 decision to allocate the 22 GHz band to satellite TV broadcasting has made it necessary to open up a new band at 25 GHz to accommodate displaced fixed service users. There will necessarily be a period when both bands will be in use for fixed services to allow migration of users. Similarly the WARC 92 decisions on the 1 3 GHz bands have resulted in a need to accommodate existing users, predominantly fixed services, elsewhere. This pressure to remove fixed services from spectrum below 3 GHz will continue, increasing the demand in other fixed service bands.
A specific requirement, resulting from WARC-92, for fixed service links to move to a nearby band will come about as a result of a CEPT agreement (Wiesbaden 1995). This allocated frequencies in the 1.5 GHz band to terrestrial digital audio broadcasting (T DAB) for use on the Continent and in the longer term the band may be required for T-DAB in the UK. Over the period to April 2007, UK fixed links in this band will be required to move to a new band at 1.4 GHz.
New European Telecommunications Standards (ETSs) are being developed for fixed services frequency bands, together with harmonized channel plans. As each new ETS becomes available, the corresponding UK Fixed Services MPT specification will be stood down. In each case the Agency will issue a document detailing which classes of equipment from the ETS will be permitted in the UK. The focus of fixed link standards work in the Agency will continue to move towards these ETSs to ensure they reflect UK requirements.
Applications for new trans-horizon links will be considered on a case by case basis. Where such use is both technically and economically justified the RA will endeavour to identify channels in the 4.4-5 GHz band with the assistance of MoD.
Where existing trans-horizon links interfere with the introduction of Mobile Satellite Service (MSS) systems in the 2 GHz band, and after discussions with the respective operators, these links will be either moved to adjacent 2 GHz spectrum or the 4.4-5 GHz band with the assistance of MoD.
The future of remaining trans-horizon links in the 2 GHz band will be assessed at regular intervals. They will be allowed to continue operations until such time as they pose interference problems to incoming mobile or MSS systems. At that stage they will be relocated as indicated above.
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