AT&T Co, British Telecommunications Plc, Apple Computer Inc, Fibronics Inc and Hewlett-Packard Co have all thrown their weight behind Fibre Distributed Data Interface over unshielded copper twisted pair. The five are part of a new industry grouping that calls itself the Unshielded Twisted Pair Development Forum and which has laid preliminary standards proposal before the same American National Standards Institution committee that is already consider plans for FDDI over shielded twisted pair from the likes of Digital Equipment Corp and Cabletron Systems Inc. The Forum admits that it still has problems – while protocols can run over the medium – as BICC Data Networks Ltd has already discovered – the consortium is finding radio frequency radiation a particular problem. A twisted pair cable running data at 100Mbps makes a very effective antenna. A number of new coding schemes are being experimented with in order to solve the problem and the group hopes to have one selected by October, following which it will make a formal proposal to ANSI.
