具有节点访问公平性的WLAN改进退避算法

An Improved Back-off Algorithm with Node Access Fairness in WLAN

以获得无线局域网(WLAN)尽可能大的吞吐量和尽量小的丢包率与平均延迟为目标,对无线局域网MAC协议中影响网络性能的载波检测机制,特别是冲突退避算法进行了深入研究.通过对现存冲突退避算法的分析,提出了一种充分考虑了节点对网络访问的公平性的改进退避算法.通过基于NS2网络仿真平台的设计与实现,对所提改进算法进行了性能仿真.结果表明,由于算法中对发送站和非发送站,根据监测到先前包是否冲突情况,采用不同的退避窗口调节策略.不仅保证了节点间数据包发送的公平性原则,其吞吐量、丢包率和包平均延迟性能都获得一定程度的提高.

In order to obtain greater throughput,smaller packet loss rate and the average delay,research on carrier detection mechanisms,especially the collision back-off algorithm which impact on network performance was carried out.By analysis to several traditional algorithms,an improved collision back-off algorithm with node access fairness is proposed.With the design and implementation of the improved algorithm using NS2,simulation to WLAN performances was performed.Because that different window regulating competition strategy,according to a previous packet monitoring the collision situation,were used for sending stations and non-sending stations,the results showed that the algorithm not only ensures the fairness of data sending among stations,but also improves the performance of throughput,packet loss rate and packet average delay to some extent.