The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 11, 1979
Filed:
Jul. 20, 1978
Robert L Carbrey, Boulder, CO (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
The disclosed signal multiplexing circuit (110) makes use of a single pair of wires (T, R) to interface a data and voice communication circuit such as an electronic key telephone (EKT) station set (100) with a central data and voice communication system such as a communication system (BCS). The signal multiplexing circuit transmits outgoing standard voice signals, outgoing auxiliary signals and outgoing data and, in turn, simultaneously receives incoming standard voice signals, incoming data and incoming auxiliary signals on the single pair of wires. Both time division and frequency separation techniques are concurrently employed to achieve multiple use of the single pair of wires without crosstalk between the plurality of signals. The data signals are transmitted as bipolar bit pairs preceded by a data start pulse pair. The outgoing data bipolar bit pairs are delayed until the center transition of the incoming data bipolar pulse pair is detected. The first half of the incoming data bipolar pulse pair appears on the line undisturbed while the second half of the same pulse pair is 'overwritten' by the first half of the outgoing data bipolar pulse pair.