基于二次曲线的无线局域网MAC退避算法  

MAC Backoff Algorithm for WLAN Based on Quadratic Curve

作　　者：王建新[1] 奎晓燕[1] 黄家玮[1] 罗玉宏[1] 

机构地区：[1]中南大学信息科学与工程学院,湖南长沙410083

出　　处：《华南理工大学学报（自然科学版）》2009年第4期7-12,共6页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(60673164);新世纪优秀人才支持计划项目(NECT-05-0683);高等学校博士学科点专项科研基金资助项目(20060533057);湖南省杰出青年基金资助项目(06JJ10009);中国博士后科学基金资助项目(20070410991);中南大学博士后科学基金资助项目

摘　　要：为提高无线局域网的吞吐量,提出了一种基于二次曲线的无线局域网介质访问控制(MAC)退避算法QIQD.该算法通过分段二次曲线计算数据帧碰撞冲突后增大竞争窗口的倍乘因子和数据帧成功传输后减小竞争窗口的倍除因子,克服了采用定常退避因子导致冲突加剧的缺点,从而降低了碰撞概率,提高了信道利用率.文中还讨论了QIQD算法中退避窗口阈值Wbasic的取值,并利用大量仿真实验验证了Wbasic=64时,QIQD算法的吞吐量和公平性能最优.仿真实验表明,QIQD算法能够有效降低站点之间的碰撞概率,增加系统整体的吞吐量,同时增强站点之间的公平性.In order to improve the throughput of wireless local area networks （ WLAN）, this paper proposes a MAC （Medium Access Control） backoff algorithm named QIQD （ Quadratic Increase, Quadratic Decrease） based on quadratic curves. QIQD uses piecewise quadratic curves to respectively calculate the muhiplicator of the contending window after a frame collision and the divisor after a successful frame transmission, and overcomes the drawbacks caused by constant backoff factor, thus reducing the collision probability and improving the channel utilization. The backoff window threshold Wbasic of QIQD is then explored and extensive simulations are performed. It is confirmed that when Wbasic= 64, QIQD possesses the highest throughput and the fairest performances. It is also found from the simulations that QIQD effectively reduces the collision probability, improves the network throughput and enhances the fairness between any two stations.

关 键 词：无线局域网 介质访问控制 退避算法 分布式协调控制 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]