A priority TDMA protocol for satellite data communications

A priority TDMA protocol is presented, aimed at supporting integrated services in a satellite network. The traffic mix includes uninterrupted Circuit-Switched (CS) digital traffic, Interactive (IA) stringent delay data packets, and moderate delay bulk data. The scheme is based on a fixed time frame, partitioned into slots dedicated to the accessing earth stations. A Network Control Center (NCC) is responsible for the slot allocation, based on the traffic load, monitored at the earth stations and reported to the control center. The slot size is depicted such as to guarantee circuit-switched uninterrupted service and interactive timely delivery, specified by 50 msec access delay with 95% confidence (or a 300 msec one-way delay when including the propagation time). The accessing earth stations fill their dedicated slots by giving priority to the various levels of outstanding traffic. The frame partition procedures are executed in regular intervals at the NCC, and the new TDMA frame format is reliably communicated to all accessing earth stations. The protocol exchange guarantees fail safe TDMA operation from unauthorized or misplaced transmission bursts