The first working cellular radiophone to the new pan-European digital standard was demonstrated at the Department of Trade & Industry in London yesterday. The phone – and radio base station – are the fruits of a UKP2m two-year joint research and development project undertaken by Racal Research, British Telecom and GEC Marconi, with additional funding from the Department. Racal was responsible for the signal processing and IF radio, Marconi did the RF modulator and wrote the software and British Telecom the speech coding trials analysis. The system has been developed to the digital transmission methods and technical standards from GSM, the Groupe Speciale Mobile, set up by the EEC Commission to establish a unified pan-European system. Although the new system is incompatible with the existing UK cellular networks, at present growth rates, capacity on those will be exhausted by 1991, when the digital system is due to be introduced. In the short term, says Industry Minister John Butcher, development of a British product to demonstration stage will give the UK an enviable competitive edge when European tendering gets under way. The system currently occupies a large rack of electronics which must be significantly reduced by 1991 when the service is due to begin; Racal is quietly confident that it will be able to do the VSLI chips needed to shrink it in time. Engineers must also grapple with the problem of delay on the speech coder, currently one tenth of a second each way.
