(19)

(11)

EP 1 155 374 A1

(12)

(43) Date of publication: 21.11.2001 Bulletin 2001/47 (21) Application number: 00902775.6 (22) Date of filing: 11.02.2000

(51) International Patent Classification (IPC)7: G06F 17/28 (86) International application number: PCT/GB0000/440 (87) International publication number: WO 0049/522 (24.08.2000 Gazette 2000/34)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 18.02.1999 GB 9903747 18.06.1999 EP 99304784 (71) Applicant: BRITISH TELECOMMUNICATIONS public limited company London EC1A 7AJ (GB)	(72) Inventor: APPLEBY, Stephen, Clifford Colchester,Essex CO7 9JQ (GB) (74) Representative: Semos, Robert Ernest Vickers  BT Group Legal Services,Intellectual Property Department,8th Floor, Holborn Centre120 Holborn London EC1N 2TE London EC1N 2TE (GB)