(19)

(11)

EP 0 935 794 A1

(12)

(43) Date of publication: 18.08.1999 Bulletin 1999/33 (21) Application number: 96935117.0 (22) Date of filing: 30.10.1996

(51) International Patent Classification (IPC):  G08B 27/ 00( . ) H04M 11/ 04( . ) G10L 13/ 00( . ) (86) International application number: PCT/GB1996/002646 (87) International publication number: WO 1998/019282 (07.05.1998 Gazette 1998/18)

(84) Designated Contracting States: BE CH DE ES FR GB IT LI NL SE (71) Applicant: BRITISH TELECOMMUNICATIONS public limited company London EC1A 7AJ (GB)

(72) Inventors: DRURY, Ian, Richard Newport, Gwent NP1 4BN (GB) BUTSANA-SITA, Beatrice, Henriette, Adrien London W2 3UD (GB) BROWN, Anthony, Michael Purley, Surrey CR8 3AG (GB) BRIDGEMAN, Seamus NewtonoMountKennedy, County Wicklow (IE) (74) Representative: Evershed, Michael  BT Group Legal Services, Intellectual Property Department, 8th Floor, Holborn Centre, 120 Holborn London EC1N 2TE London EC1N 2TE (GB)