(19)

(11)

EP 0 296 201 A1

(12)

(43) Date of publication: 28.12.1988 Bulletin 1988/52 (21) Application number: 88900547.0 (22) Date of filing: 05.01.1988

(51) International Patent Classification (IPC):  H04B 10/ 20( . ) H04B 10/ 207( . ) H04J 14/ 08( . ) H04Q 11/ 00( . ) H04B 10/ 155( . ) H04J 3/ 06( . ) H04L 25/ 03( . ) H04J 14/ 02( . ) (86) International application number: PCT/GB1988/000004 (87) International publication number: WO 1988/005233 (14.07.1988 Gazette 1988/15)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 05.01.1987 GB 19870000069 06.05.1987 GB 19870010736 05.10.1987 GB 19870023282 27.11.1987 GB 19870027846 (71) Applicant: BRITISH TELECOMMUNICATIONS public limited company London EC1A 7AJ (GB)	(72) Inventors: FAULKNER, David, Wynford Ipswich Suffolk IP5 7SU (GB) PAYNE, David, Brian Wickham Market Suffolk IP13 0SD (GB) STERN, Jeffrey, Richard Ipswich Suffolk IP6 9NX (GB) (74) Representative: Greenwood, John David, et al  British Telecom Intellectual Property Unit 151 Gower Street London WC1E 6BA London WC1E 6BA (GB)