A Novel Random Access Protocol for Ad Hoc Wireless LANs
Wang Chun · Dianzi xuebao · 2005
The BSAC (buffered S-ALOHA CDMA) protocol that applies to the Ad Hoc Wireless LANs is analyzed,and its analytical model is first proposed by Markovian chain approach in this paper.The analytical model uses two Markovian chains;one is for the M/M/1/k queuing model in the individual node,and another is for the number of the busy nodes in whole networks.Two Markovian chains are connected by the idle probability of queue.The effect which the analytical model's input parameters of throughput,delay and times of failure to deliver has on its performance metric of spreading gain,queue size and maximum allowable number of retransmissions is analyzed.The throughput bound of the B-SAC protocol is given.Besides,the delay-capture technology is introduced to greatly decrease the probability of collision of packets and improve the throughput by averagely 29.1% and improve the maximum throughput by 20.8% compared with the pure BSAC protocol and close to theoretical bound.