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Asynchronous Multiplex System

IP.com Disclosure Number: IPCOM000089999D
Original Publication Date: 1969-Jan-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Clark, BS: AUTHOR [+2]

Abstract

The asynchronous multiplex system allows the time division multiplexing of a plurality of information channels which can be operated at different rates slower than the base data rate of the multiplexer. The message format of each transmitted message for each channel consists of sync bits, count bits, data bits and a bit position for an extra data bit. The sync bits identify the start of the message. The count bits signify how many times the extra data bit position is used. The data bits contain data. The extra data bit allows the data to be expanded by one bit position.

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Asynchronous Multiplex System

The asynchronous multiplex system allows the time division multiplexing of a plurality of information channels which can be operated at different rates slower than the base data rate of the multiplexer. The message format of each transmitted message for each channel consists of sync bits, count bits, data bits and a bit position for an extra data bit. The sync bits identify the start of the message. The count bits signify how many times the extra data bit position is used. The data bits contain data. The extra data bit allows the data to be expanded by one bit position.

Each of the n channels can operate at a different rate. As a data bit is received on an input line D1...Dn, it is stored in bit storage 5. Adaptive channel control 1 measures accurately the time between data bits on each input channel and stores this information in control memory 2. The time associated with each channel is in turn used to control the transmitting of data from storage 5 to data memory 4. The latter is divided into n buffer areas 8 which store the input data from storage 5. The number of bits stored in each area 8 dictates the use of the extra data bit of the message format. When a threshold of an allowable number of data bits to be stored within areas 8 of memory 4 is surpassed, then the extra data bit position of the message format is used to alleviate this condition. The count of how many times the extra data bit is used is increased by 1. Message fo...