COMBINED FIXED AND DEMAND ASSIGNMENT SATELLITE MULTIPLE ACCESS PROTOCOL FOR INTEGRATED CIRCUIT AND PACKET SWITCHING.

The authors consider a satellite system operated as a time-division multiple-access (TDMA) broadcast channel serving a large number of ground stations. They study the performance of the combined fixed- and demand-assignment multiple-access technique with integrated circuit and packet switching. Two models of voice traffic are considered. These are call initiation and termination and talkspurt/silence alternation of speakers. The combined scheme is analyzed, using a Markov chain model to determine its performance for both fixed and movable boundary schemes. The authors show that the overall performance of the combined scheme with movable boundary is superior to the one with fixed boundary. They also show that the movable boundary improves the performance in the combined protocol, but the performance of the pure F-TDMA system with movable boundary is degraded during the period of time when the voice traffic load exceeds its statistical average.