(19)

(11)

EP 0 645 066 A1

(12)

(43) Date of publication: 29.03.1995 Bulletin 1995/13 (21) Application number: 93913331.0 (22) Date of filing: 09.06.1993

(51) International Patent Classification (IPC):  H04L 25/ 06( . ) (86) International application number: PCT/GB1993/001226 (87) International publication number: WO 1993/026110 (23.12.1993 Gazette 1993/30)

(84) Designated Contracting States: DE FR GB (30) Priority: 10.06.1992 GB 19920012263 (71) Applicant: AT & T WIRELESS COMMUNICATIONS PRODUCTS LIMITED Winchester, Hampshire S023 7BH (GB)	(72) Inventors: McCABE, David James Winchester, Hampshire SO22 4EW (GB) WILLIAMS, Stephen Akira Southampton, Hampshire SO2 1LN (GB) BEESLEY, Graham, Edgar Sparsholt Winchester SO21 2NJ Hampshire (GB) (74) Representative: Boydell, John Christopher, et al  Stevens, Hewlett & Perkins 1 Serjeants' Inn Fleet Street London EC4Y 1LL London EC4Y 1LL (GB)