Adaptive retransmission control of slotted ALOHA frequency-hopped spread-spectrum multiple access communication networks

Abstract

In this paper we examine the retransmission control policies of slotted ALOHA frequency-hopped spread-spectrum multiple access system. Optimal packet arrival distribution at the input of the channel that maximizes the channel throughput is found. Based on this, we derive a quasi-optimal retransmission control (QORC) policy which changes the retransmission probability adaptively as a function of the system state such that channel throughput can be maximized. QORC policy is shown to provide a significant performance improvement over the fixed retransmission probability control. Steady state performance improvement obtained by using QORC policy is presented for various input traffic intensity. Finally, the sensitivity of the QORC policy to state estimation error is investigated.