Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AT&T Inc
Original Assignee
American Telephone and Telegraph Co Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US06/714,834external-prioritypatent/US4852127A/en
Application filed by American Telephone and Telegraph Co IncfiledCriticalAmerican Telephone and Telegraph Co Inc
Priority to CA000570443ApriorityCriticalpatent/CA1255007A/fr
Application grantedgrantedCritical
Publication of CA1255007ApublicationCriticalpatent/CA1255007A/fr