(19)

(11)

EP 0 341 271 A1

(12)

(43) Date of publication: 15.11.1989 Bulletin 1989/46 (21) Application number: 88907742.0 (22) Date of filing: 26.08.1988

(51) International Patent Classification (IPC):  G10L 19/ 08( . ) H04B 14/ 04( . ) (86) International application number: PCT/GB1988/000711 (87) International publication number: WO 1989/002148 (09.03.1989 Gazette 1989/06)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 28.08.1987 GB 19870020388 28.01.1988 GB 19880001858 (71) Applicant: BRITISH TELECOMMUNICATIONS public limited company London EC1A 7AJ (GB)	(72) Inventors: XYDEAS, Costas Wilmslow Cheshire (GB) GOUVIANAKIS, Nikolaos Manchester M21 1HR (GB) (74) Representative: Lloyd, Barry George William, et al  Intellectual Property Unit British Telecom Room 1304 151 Gower Street London WC1E 6BA London WC1E 6BA (GB)