(19)

(11)

EP 0 781 496 A1

(12)

(43) Date of publication: 02.07.1997 Bulletin 1997/27 (21) Application number: 95931280.0 (22) Date of filing: 08.09.1995

(51) International Patent Classification (IPC):  H04J 3/ 00( . ) H04J 3/ 16( . ) H04B 7/ 24( . ) H04W 74/ 08( . ) (86) International application number: PCT/GB1995/002128 (87) International publication number: WO 1996/008938 (21.03.1996 Gazette 1996/13)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 16.09.1994 GB 19940018747 (71) Applicant: Ionica International Limited Cambridge CB4 4AS (GB)	(72) Inventors: BROCK, David, Charles Cambridge CB4 4UD (GB) GOODINGS, Rupert, Leslie, Alexander Cambridge CB4 1DD (GB) MARTIN, Paul, Maxwell Suffolk CB8 9XS (GB) McARTHUR, Roger, James Cambridge CB4 4BA (GB) SHORE, Christopher, John Cambridge CB4 1UP (GB) (74) Representative: Sarup, David Alexander, et al  Withers & Rogers 4 Dyer's Buildings, Holborn London EC1N 2JT London EC1N 2JT (GB)