Elimination of bistability in spread-spectrum multiple-access networks
R. Murali, B.L. Hughes · 2002
The article considers packet radio networks in which users transmit using spread-spectrum multiple-access (SSMA) signaling, slotted ALOHA random access, and forward-error-correction (FEC). It is well known that these networks can exhibit bistable behavior similar to narrowband ALOHA systems. We analyze the impact of FEC parameters on the throughput, delay, and drift of slow frequency-hop (FH)/SSMA networks. We present exact expressions for throughput, delay, and drift, and, furthermore, characterize bistable systems by their first exit times (FET). Drift analysis suggests an approach to eliminating bistability that involves increasing both the average retransmission time and the blocklength. Numerical examples are provided to illustrate our approach. A noteworthy feature of this approach is that the elimination of bistability is achieved by careful selection of system parameters without using active control.