Eric H Angell, 82158 Algonquin Park, Plattsburgh, NY 12901

4716561, Dec 29, 1987

Aug 26, 1985

6/769509

Eric H. Angell - North Andover MA
Thomas J. Aprille - Andover MA
Juan O. Azaret - North Andover MA
Rong-Chin Fang - North Andover MA
Byeong G. Lee - Methuen MA
Brian C. Longwell - Kingston NH
Craig A. Sharper - Bradford MA
Jan-Dieter Spalink - Woodbridge VA

American Telephone and Telegraph Company, AT&T Bell Laboratories - Murray Hill NJ

H04J 110
H04J 308

370 55

In a transmission system, adding and/or dropping any one or more of a plurality of digital signals of one or more digital transmission bit rates is facilitated by employing a unique transmission signal in which data words associated with individual digital signals are arranged in prescribed groups. The transmission signal data word groups are obtained by formatting the individual digital signals to be combined into a unique channel frame format common to all of the digital signals and by employing a unique one-step multiplexing process to insert digital words from the channel frames into the group of data word positions in the transmission signal associated with the particular signal being combined. Consequently, digital signals may be added to the transmission signal by formatting them into the common channel frame format and, then, inserting the digital words therefrom in the one-step multiplexing process into an associated group of data words positions in the transmission signal. Digital signals are dropped from the transmission signal by extracting associated groups of data words from the transmission signal, identifying the corresponding channel frames and deformatting the data bits from channel frames of corresponding digital signals being reconstructed.

4905228, Feb 27, 1990

May 9, 1988

7/219121

Eric H. Angell - North Andover MA
Thomas J. Aprille - Andover MA
Rong-Chin Fang - North Andover MA
Byeong G. Lee - Methuen MA
Jan-Dieter Spalink - Woodbridge VA

American Telephone and Telegraph Company - New York NY
AT&T Bell Laboratories - Murray Hill NJ

H04J 322

370 84

A plurality of digital signals of one or more digital transmission bit rates are arranged to be combined by employing a unique common channel frame format. The channel frame format includes a plurality of data bit positions and a plurality of overhead bit positions. The number of data bit positions used is dependent on the particular incoming signal. Similarly, the number of frames generated during a specific common framing interval is dependent on the digital transmission bit rate of the particular signal. Specifically, the number of channel frames generated during the common channel frame interval is dependent on a number of equivalent so-called lowest transmission bit rate signals included in the particular signal being formatted. The overhead bits are distributed in the channel frame format.

4924459, May 8, 1990

Sep 27, 1988

7/250026

Eric H. Angell - North Andover MA
Thomas J. Aprille - Andover MA
Rong-Chin Fang - North Andover MA
Byeong G. Lee - Methuen MA
Jan-Dieter Spalink - Woodbridge VA

AT & T Bell Laboratories - Murray Hill NJ

H04J 322

370 84

A plurality of digital signals of one or more digital transmission bit rates are combined into a single transmission signal by employing a unique common channel frame format and one step multiplexing process. The channel frame format includes a plurality of data bit positions and a plurality of overhead bit positions. The number of data bit positions used is dependent on the particular incoming signal. Similarly, the number of frames generated during a specific common framing interval is dependent on the digital transmission bit rate of the particular signal. Specifically, the number of channel frames generated during the common channel frame interval is dependent on a number of equivalent so-called lowest transmission bit rate signals included in the particular signal being formatted. The overhead bits are distributed in the channel frame format. Digital words from the channel frames are inserted into predetermined groups of data word positions in a repetitive frame of a single transmission signal.