中文摘要：

在基于IEEE 802.11的移动自组织网络中,MAC（Medium Access Control）层提供了DCF（Distributed Coordi-nate Function）以控制节点对无线信道的争用.DCF包括了BEB（Binary Exponential Backoff）算法.该文对BEB的重要参数——竞争窗口CW（Contention Window）进行研究,通过随机建模,导出了竞争窗口长度的概率分布,并进行数值分析.研究结果可应用于IEEE 802.11移动自组织网络.

英文摘要：

In an IEEE 802.11 based mobile ad hoc network（MANET）,the wireless channel is accessed through the DCF（Distributed Coordinate Function）,which is provided at the MAC（Medium Access Control） layer of the IEEE 802.11 standard to control channel contention among nodes.The DCF embeds the BEB（Binary Exponential Backoff） algorithm.The key parameter CW（contention window） of the BEB is investigated by stochastic analysis modeling so that the probability distribution of the contention window size is derived.Numeric results are presented to analyze the performance of the BEB.The derived probability distribution is applicable in MANETs.