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Priority claimed from GB868626786Aexternal-prioritypatent/GB8626786D0/en
Priority claimed from GB878723794Aexternal-prioritypatent/GB8723794D0/en
Application filed by British TelecommfiledCriticalBritish Telecomm
Priority claimed from EP19870309818external-prioritypatent/EP0267744B1/de
Application grantedgrantedCritical
Publication of ATE62647T1publicationCriticalpatent/ATE62647T1/de