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AssigneeInternational Standard Electric Corporation
InventorsKeith Graham, Viacheslav Korsky, Christopher Elmer, Edouard Pinede, John Litster, Jan Aarts
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A telecommunications system using TDM principles for signalling and speech path usage plus PAM principles for speech transmission. Each function circuit such as a trunk, link or register, etc. is allocated a basic time slot or channel for initiation of its function when indicated. The active period of each function circuit is continued during the period of three succeeding time slots. In this way, up to four function circuits or channel units may be active during a finite period of time. In the system, a line is scanned at the end of each complete scan of all channels, thereby lessening the complexity of associating a line and a function circuit. The system shown uses the dual highway principle for its speech path and provision is made in each line circuit for switching onto both highways.
A telecommunications exchange comprising a central control including a processor and a memory, and a plurality of stations;
A time division telecommunications exchange wherein there are a plurality of time channels comprising a time frame, a plurality of circuits for supervising exchange functions with each of said channels representing a separate one of said function circuits, means operative during each time channel for storing calling and called line data on calls being handled by the associated function circuit, line scanner means operative at the conclusion of each time frame to scan one line for call service request, a register comprising one of said function circuits, means operative during the time frame subsequent to a line scan finding a line seeking call service for associating said register with said seeking line, means in said register for receiving dialed digits from the calling line for identifying a called line, means in said register for testing the called line for availability, and a central processor responsive to a called line being found available on said testing for transferring the call being serviced from said register to a further function circuit.
Dependencies are inferred from the claim text.