(19)

(11)

EP 0 956 631 A2

(12)

(43) Date of publication: 17.11.1999 Bulletin 1999/46 (21) Application number: 98900927.0 (22) Date of filing: 20.01.1998

(51) International Patent Classification (IPC):  H02J 13/ 00( . ) H01H 85/ 46( . ) H04B 3/ 56( . ) (86) International application number: PCT/GB1998/000173 (87) International publication number: WO 1998/033258 (30.07.1998 Gazette 1998/30)

(84) Designated Contracting States: DE ES FI FR GB IT NL SE (30) Priority: 28.01.1997 GB 19970001701 05.06.1997 US 19970869257 (71) Applicant: NORTEL NETWORKS CORPORATION Montreal, Quebec H2Y 3Y4 (CA)	(72) Inventor: GREENWOOD, John, Christopher London E15 1HL (GB) (74) Representative: Cage, John David, et al  Nortel Networks, IP Law Group, London Road Harlow, Essex CM17 9NA Harlow, Essex CM17 9NA (GB)