The provision of circuits to outside broadcast locations using spectrum within the UHF broadcasting bands

The demand for circuits for outside broadcasts has up to the present time been met by rented lines or spectrum specifically allocated for services ancillary to broadcasting. The use of rented lines to provide these circuits is now proving increasingly restrictive to outside broadcast operations. Programme and control circuits from the outside broadcast locations to the production centres can usually be engineered from available spectrum. However, problems arise in planning the reverse links which carry control, coordination, and audio monitoring circuits to the outside broadcast. These reverse links are commonly known as 'reverse bearers'. In line with a recommendation that UK broadcasters be encouraged to exploit the potential for sharing spectrum within the UHF television bands to maintain or expand services ancillary to broadcasting, it is proposed that reverse bearers are transmitted from UHF main transmitter sites, in the lower adjacent channels to broadcasting. The planning aspects of making such reverse bearer transmissions are discussed together, with the results of a system field trial carried out from the Crystal Palace television transmitting station, situated in South East London. The application of the findings are then considered in the future provision of an operational system to cover the London area.<>