David A Trimble

US Patent:

43118780, Jan 19, 1982

Filed:

Jul 2, 1979

Appl. No.:

6/053780

Inventors:

Paul R. Berkowitz - Red Bank NJ
Thomas M. Quinn - Little Silver NJ
David C. Trimble - Holmdel NJ
Tse L. Wang - Matawan NJ

Assignee:

Bell Telephone Laboratories, Incorporated - Murray Hill NJ

International Classification:

H04M 140

US Classification:

179 16EC

Abstract:

A transmission arrangement for use in a customer premises communication system is operable for controlling transmission during the MF digit signaling interval in situations where it is necessary to convert station dialed MF signals to pulsed digit signaling. In systems where the signaling station, the MF to dial pulse converter and the Central Office or PBX line are bridged on the same communication link it is possible for the station's MF signals to be detected by the MF receiver in the Central Office, thereby causing errors in the received digits. These problems are eliminated by inserting two transmission gates in the four-wire portion of the CO line. The gates are controlled by the processor in the customer premises communication system such that the outward gate is opened immediately upon seizure of the line by the calling station and remains open during the entire dialing interval. The inward gate is opened concurrently with the operation of the digit outpulsing relay and remains operated on a digit by digit basis.