(19)

(11)

EP 1 072 129 A1

(12)

(43) Date of publication: 31.01.2001 Bulletin 2001/05 (21) Application number: 99918113.4 (22) Date of filing: 20.04.1999

(51) International Patent Classification (IPC)7: H04L 12/56, H04N 7/26 (86) International application number: PCT/GB9901/197 (87) International publication number: WO 9955/046 (28.10.1999 Gazette 1999/43)

(84) Designated Contracting States: DE ES FR GB IT NL (30) Priority: 20.04.1998 EP 98303022 (71) Applicant: BRITISH TELECOMMUNICATIONS public limited company London EC1A 7AJ (GB)	(72) Inventors: WILLIS, Ben Suffolk IP4 5UX (GB) BEAUMONT, David, Owen Suffolk IP5 3SU (GB) (74) Representative: Garrison, Christopher Sinclair et al British Telecommunications plc,BT Group Legal Services,Intellectual Property Department,8th Floor,120 Holborn London EC1N 2TE London EC1N 2TE (GB)