Local call completion for time division multiplexing system
AssigneeInternational Standard Electric Corporation
InventorDonald Adams Weir
Life of this patent
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Abstract
Apparatus within a time division multiplex telecommunications system for terminating local traffic at a local distributing center and eliminating the need for use of channels to the switching center. The system employs time slots for calls to the switching center and other time slots for local calls. Digits representing the called line are stored in a register at the calling station. The register is interrogated after sufficient digits have been stored to inidicate the destination as local or switching center. When a local call is recognized, a bistable in the local distributing center is set. When the end of dialing signal is received, a code is generated to release the channel connection to the main exchange and to complete the call locally over time slots dedicated to serving local calls.
Claims4
An automatic telecommunications switching system comprising a switching center, a plurality of subscriber lines coupled to said center over a plurality of time division multiplexed highways with each of said highways coupled to a plurality of subscriber lines to provide call service to said lines, a distribution circuit coupled to one of said highways intermediately between the subscriber lines served by said highway and the switching center for serving a plurality of subscriber lines over said highway, each time frame of the time multiplex of said one highway being divided into a first group of time slots for connection from a subscriber line seeking a call connection through a selected idle one of said time slots through said switching center and a second group of slots for local call connections between two or more subscriber lines served by said distribution circuit, and means in said distribution circuit responsive to recognition of a call as being directed to a subscriber line served by said distribution circuit for switching said local call to a selected idle one of said second group of slots independently of the switching center.
Dependencies are inferred from the claim text.