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Priority claimed from GB838315046Aexternal-prioritypatent/GB8315046D0/en
Application filed by British TelecommfiledCriticalBritish Telecomm
Priority claimed from EP83306066Aexternal-prioritypatent/EP0106640B1/de
Application grantedgrantedCritical
Publication of ATE20796T1publicationCriticalpatent/ATE20796T1/de