There are one or two UK Personal Communications Network consortia looking for new investors, and in the medium term, AT&T Co may well be interested. Ma Bell has recognised that wireless telephony may one day pose a serious threat to wired telecommunications and wants in – and Personal Communications Network could also take it back into the local phone business which it divested in return for being allowed to enter deregulated businesses. Moreover now that its long distance network in the US is almost all fibre optic, it has a string of 3,000 now very underexploited microwave towers across the US. All of which has attracted it to the idea of Personal Communications Network, the UK-conceived idea of pocket telephones that communicate via a mini-cellular system mini-cellular because the cells are much smaller and the transmitters much lower power. AT&T has filed with the Federal Communications Commission for permission to initiate tests that would start late this year and continue to the end of 1993. It wants to use frequencies that it already owns, and at present uses only for maintenance tests, and it is asking for a three-phase trial. In the first phase, it would simply test whether heavy use of the frequencies would interfere with other traffic. The second would be to prove the viability of the telephones themselves, and the third would involve mass market trials in Los Angeles, Boston and Atlanta. The company has been working since last August with Qualcomm Inc, San Diego on that company’s code division multiple access system, which multiplexes calls by attaching a different code to each to pack up to 20 times as many calls into a given frequency. The trials will be at frequencies between 5.9GHz and 6.4GHz and the company is looking to hand out phones to some 3,000 people in the three cities in the final phase.
