Improving the satellite communication efficiency of the accumulative acknowledgement strategies

The performances of two finite buffer error recovery strategies-HDLC-Ms.SREJ+REJ and the q.SREJ modified protocols-are analyzed. In both strategies the retransmission request decision between selective repeat and continuous retransmission is based on an imminent buffer overflow condition. These are accumulative acknowledgement schemes, but in the second strategy the selective-repeat control frame is uniquely an individual negative acknowledgement. The two strategies take advantage of the availability of a greater buffer capacity, making the most of the selective repeat, postponing the sending of a continuous retransmission request. Numerical results show a better performance very close to the ideal, but it does not integrally conform to the high-level data link control (HDLC) procedures. It is shown that these strategies are well suited for high-speed data transfer in the high-error-rate satellite environment