David Wynne Storey

US Patent:

49657879, Oct 23, 1990

Filed:

Feb 9, 1989

Appl. No.:

7/308705

Inventors:

Gary R. Almond - Frederick MD
David W. Storey - Dickerson MD

Assignee:

Data General Corporation - Westboro MA

International Classification:

H04J 322

US Classification:

370 581

Abstract:

Methods and apparatus are set forth which improve the efficiency of bandwidth usage over the CCITT I. 463 standard, for switching systems having a granularity of better then 64 Kbps (e. g. 8 Kbps). Furthermore, methods and apparatus are set forth which are capable of performing rate adaptation for synchronized sub-rate channels in a manner geared to package sub-rate data in fragment size envelopes (or integer multiples thereof), where the width of a fragment is matched (ideally equal) to the granularity of the system's switch. This improves the efficiency of the rate adaptation process and maximizes the use of the system's switching and bandwidth capacity.

US Patent:

49875701, Jan 22, 1991

Filed:

Feb 9, 1989

Appl. No.:

7/308354

Inventors:

Gary R. Almond - Frederick MD
David W. Storey - Dickerson MD

Assignee:

Data General Corporation - Westboro MA

International Classification:

H04J 307

US Classification:

370 84

Abstract:

Methods and apparatus are set forth which improved the sub-rate channel carrying capacity and the efficiency of bandwidth usage, over the CCITT I. 463 standard, for switching systems having a switching "granularity", defined as the smallest channel size that can be switched through the system, of better then 64 Kbps (e. g. a switching system that can switch 8 Kbps fragments). These methods and apparatus are capable of performing rate adaptation for multiple synchronized subrate channels in accordance with a predefined multiplexing protocol. The protocol calls for "time interleaved" multiplexed rate adaptation to be performed, i. e. , multiple sub-rate channel data is packaged into fragment size envelopes (or integer multiples thereof). The width of a fragment is also matched (ideally equal) to the granularity of the system's switch. As a result of using the time interleaved multiplexed rate adaptation scheme, the rate adaptation process, the channel carrying capacity of the system at large, and the use of the system's switching and bandwidth capacity are all improved.