IEEE 802.11e无线局域网中改进信道接入的简单策略  

Enhancement of Channel Access Mechanism for IEEE 802.11e WLANs

作　　者：程艳红[1] 李志蜀[1] 朱丽[1] 

机构地区：[1]四川大学计算机学院,成都610065

出　　处：《系统仿真学报》2009年第3期695-699,715,共6页Journal of System Simulation

基　　金：国家中小企业创新基金(06C26225101730);四川省科技厅重点项目(05GG021-003-2)

摘　　要：针对IEEE 802.11e在高负载下性能降低的问题,提出了一种改进信道接入的策略,这是一种不需要通过实时测量来估计网络状态的简便策略。该策略根据竞争窗口(CW)的大小改变各业务流的仲裁帧间间隔(AIFS),从而使各业务流能适应网络状态动态调整其优先级,同时结合减慢CW在成功传输时更新速度的措施以降低高负载下的冲突概率。仿真结果表明该策略不仅能提升各优先级业务流的吞吐量、时延和抖动等性能,而且能改善高负载下各优先级业务流之间信道的不公平分配,明显减轻了低优先级业务流的饥饿现象,同时提高了相同优先级业务流的公平性。A simple and efficient mechanism was proposed to enhance channel access for IEEE 802.1 le without needing to estimate channel status through real-time measurement, which allows first, dynamic priorities provision by adjusting the arbitrary interframe space （AIFS） parameter according to the size of the Contention Window （CW）, secondly, the decrease of the collision probability by reducing the update speed of the CW after each successful transmission. The extensive simulation results show that the proposed scheme outperforms the IEEE 802.1 l e EDCF in throughput, delay and jitter and at the same time ameliorates starvation of low priority traffics and improves the fairness among the traffics with the same priority.

关 键 词：802.11e 无线局域网 QOS 公平性 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]