(19)

(11)

EP 0 115 486 A1

(12)

(43) Date of publication: 15.08.1984 Bulletin 1984/33 (21) Application number: 83900770.0 (22) Date of filing: 26.01.1983

(51) International Patent Classification (IPC):  H04Q 11/ 04( . ) (86) International application number: PCT/US1983/000121 (87) International publication number: WO 1984/000660 (16.02.1984 Gazette 1984/05)

(84) Designated Contracting States: DE FR GB NL (30) Priority: 29.07.1982 US 19820403093 (71) Applicant: Western Electric Company, Incorporated New York, NY 10038 (US)	(72) Inventor: CHANG, Shih-Jeh Naperville, IL 60540 (US) (74) Representative: Weitzel, David Stanley, et al  Western Electric Company Limited 5, Mornington Road Woodford Green Essex IG8 0TU Woodford Green Essex IG8 0TU (GB)