Eugene C Anderson

US Patent:

42477409, Jan 27, 1981

Filed:

Jul 19, 1979

Appl. No.:

6/059080

Inventors:

Eugene S. Anderson - Naperville IL
Charles D. Gavrilovich - Naperville IL

Assignee:

Bell Telephone Laboratories, Incorporated - Murray Hill NJ

International Classification:

H04M 1500
H04Q 354
H04Q 358

US Classification:

179 18AH

Abstract:

A trunk interface circuit (105) is disclosed for executing communication and signaling functions associated with telephone calls between subscriber stations of separate telecommunication systems (100, 140). A semiautonomous control circuit (200) is responsive to state signals generated from a central control circuit (120) for establishing the trunk interface circuit (105) in a plurality of states. The semiautonomous control circuit (200) comprises a memory (320) having predetermined data stored therein corresponding to each of the plurality of states. A processor (300) within the semiautonomous control circuit (200) executes certain of the communication and signaling functions as determined by the stored data corresponding to the present state of the trunk interface circuit (105). The communication functions comprise reception of periodic charging pulses from a distant office and subsequent transmittal of signals to the central control circuit (120) representative of the charging pulses.