High capacity low delay packet broadcasting multiaccess schemes for satellite repeater systems
Abstract
Demand assigned packet radio schemes using satellite repeaters can achieve high capacities but often exhibit relatively large delays under low traffic conditions when compared to random access. Several schemes which improve delay performance at low traffic but which have high capacity are presented and analyzed. These schemes allow random acess attempts by users, who are waiting for channel assignments. The performance of these are considered in the context of a multiple point communication system carrying fixed length messages between geographically distributed (ground) user terminals which are linked via a satellite repeater. Channel assignments are done following a BCC queueing discipline by a (ground) central controller on the basis of requests correctly received over a collision type access channel. In TBACR Scheme A, some of the forward message channels are set aside for random access transmissions; the rest are used in a demand assigned mode. Schemes B and C operate all their forward message channels in a demand assignment mode but, by means of appropriate algorithms for trailer channel selection, allow random access attempts on unassigned channels. The latter scheme also introduces framing and slotting of the time axis to implement a more efficient algorithm for trailer channel selection than the former.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- December 1980
- Bibcode:
- 1980PhDT........71B
- Keywords:
-
- Broadcasting;
- Communication Satellites;
- Repeaters;
- Access Time;
- Algorithms;
- Optimization;
- Queueing Theory;
- Random Processes;
- Communications and Radar