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.