(19)

(11)

EP 0 752 178 A1

(12)

(43) Date of publication: 08.01.1997 Bulletin 1997/02 (21) Application number: 95911448.0 (22) Date of filing: 21.03.1995

(51) International Patent Classification (IPC):  H04L 1/ 22( . ) H04J 3/ 08( . ) H04Q 11/ 04( . ) H04J 3/ 00( . ) H04J 3/ 14( . ) (86) International application number: PCT/GB1995/000618 (87) International publication number: WO 1995/026084 (28.09.1995 Gazette 1995/41)

(84) Designated Contracting States: BE DE ES FR IE IT NL (30) Priority: 23.03.1994 GB 19940005771 (71) Applicant: GPT LIMITED Coventry, CV3 1HJ (GB)	(72) Inventor: BARKER, Andrew, James Nottingham NG9 6BP (GB) (74) Representative: Burrington, Alan  GEC Patent Department, Waterhouse Lane Chelmsford, Essex CM1 2QX Chelmsford, Essex CM1 2QX (GB)