American Telephone & Telegraph Co., At&t Bell Laboratories

American Telephone and Telegraph, Co.

At&t Information Systems Inc.

Duane Galensky

Adrian A Giuliani

Warren G Hammett

A bit compression multiplexer for a pair of time division multiplexed digital bit streams each one of which includes a plurality of PCM encoded signals deposited in separate and distinct channels and signaling bits multiplexed therewith. The encoded signals are bit compressed (22), and then multiplexed and grouped (25) into clusters. Each of the multiplexed compressed signals occupies a separate and distinct channel of a repetitive frame that includes a plurality of clusters and a corresponding number of additional channels, called delta channels, each one of which is associated with a given cluster and is proximate thereto. The signaling bits are extracted (21) from the pair of digital bit streams, reformatted (24) and then placed in predetermined bit positions of the delta channels. The signaling bits in a given delta channel are associated with the compressed signals of a cluster proximate thereto. The combination of a cluster and its related delta channel comprise a bundle. A framing bit pattern is developed (23) for each bundle and the framing bits are placed into a predetermined bit position of each of the delta channels.

Bit compression multiplexing

A communication system includes station sets having one or more function enable buttons and a plurality of line access buttons. The function enable buttons include the extension, transfer and send message buttons. Each line select button is associated with a communication line and with the station set associated with that line. Operation of a function enable button initiates the feature associated with that button and also changes the function of a line select button from a line access button to an auto-dial select button for dialing the station associated with the line select button.

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Holmdel, NJ, United States of America

Duane Galensky