Arthur R Bonham

US Patent:

40597296, Nov 22, 1977

Filed:

Jun 9, 1976

Appl. No.:

5/694302

Inventors:

Wesley L. Eddy - Howey-in-the-Hills FL
Daniel J. Mullen - Orlando FL
Arthur R. Bonham - Orlando FL

Assignee:

Martin Marietta Aerospace - Orlando FL

International Classification:

H04J 314

US Classification:

179 15BF

Abstract:

A method and system for accessing data in a time division multiplex communication network at the multiplexed level without disturbing the transmission of the data. A multiplexed data stream containing a predetermined pattern of framing signals and subscriber data from a plurality of subscriber channels is accessed directly by line accessing means located in the transmission path of the data stream. The line accessing means does not disturb the transmission of the multiplexed data stream, i. e. , allows the multiplexed data stream to pass through the line accessing means, but provides a monitored data signal having the same data content as the multiplexed data stream, thereby essentially providing undisturbed direct access to the multiplexed data stream. A control signal designating one of the plurality of subscriber channels as the desired subscriber channel is generated, and framing signals in the multiplexed data stream are detected. The detected framing signals and the generated control signal are utilized to locate the designated one of the plurality of subscriber channels in the monitored multiplexed data stream for monitoring, testing or for use of the data contained in the located channel.