Performance analysis of multiple access protocols for multimedia satellite networks

In this paper, several TDMA-based packet multiple access protocols are studied and evaluated in the geostationary satellite environment. The distributed queueing random access protocol, DQRAP, originally proposed for HFC networks is adapted to the satellite environment. Another protocol, the announced retransmission random access protocol, ARRA, proposed for wireless networks is also studied. Both protocols are modeled and simulated in a VSAT network context. We then propose a new protocol which combines the advantages of both studied schemes and is more adapted to interactive multimedia applications over satellite uplinks, The generalized retransmission announcement protocol, GRAP, regroups the immediate access by contention at low loads, and the reservation access at higher loads, to achieve a better channel efficiency. An analytical model is proposed to calculate the channel throughput obtained by GRAP under different Loading conditions. Simulation results illustrate an improved throughput/delay characteristics and a higher protocol stability compared to both DQRAP and ARRA, Enhanced versions of the protocol are also proposed and evaluated to further improve its efficiency, with reasonable additional complexity.