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:
Oct. 25, 1994
Filed:
Jun. 15, 1993
Robert W Steagall, North Salt Lake, UT (US);
Steven T Barham, Salt Lake City, UT (US);
John W Love, Bountiful, UT (US);
Unisys Corporation, Blue Bell, PA (US);
Abstract
An interface for coupling a standard telephone set to a distributed digital network for allowing digital voice communication over the distributed network such that the utilization of the distributed network is wholly transparent to the user. An interface is provided for each telephone set. Each interface includes a state machine, a coder/decoder and a digital tone generator. The state machine is responsive to analog control signals from the telephone set to generate digital control signals to be transmitted over the distributed network. The state machine is also responsive to digital control signals to control the digital waveform generator to generate supervisory tones which are relayed to the user by the telephone set. The state machine also monitors the operation of the corresponding state machine or machines in a normal or conference call and sends control signals to resolve inconsistent states of the respective state machines, resulting in a high degree of fault tolerance and independence from network protocols.