基于虚拟竞争窗口的802.11区分服务机制  

A Service Differentiation Scheme based on Virtual Contention Window in IEEE 802.11 WLAN

作　　者：徐颖[1] 

机构地区：[1]南京航空航天大学金城学院

出　　处：《科技致富向导》2011年第30期76-76,89,共2页Guide of Sci-tech Magazine

摘　　要：针对802.11DCF不能支持区分服务的问题,本文提出了一种基于虚拟竞争窗口的DCF改进机制。在每个数据包由网络层传送给MAC层之前站点发起一次＂虚拟竞争＂。该机制采用Markov Chain模型进行数学分析,通过区分虚拟竞争窗口和重传限制,实现饱和吞吐量的相对区分。仿真结果表明该机制能有效提高高优先级数据流的传输性能,实现区分服务。Considering that 802.11 DCF doed not support any QoS differentiation, this paper proposes a novel scheme based on virtual contention window. A station will initiate a virtual contention process before every date packet frome network layer being delivered to MAC laver. We propose an Markov chain model for the scheme which can achieve saturation throughput differentiation by differentiating the virtual contention window and the retry limit. Simulation results demonstrate that the mechanism can improve the transmission performance of data flows in high priority significantly and support QoS effectively.

关 键 词：DCF 虚拟竞争 区分服务 饱和吞吐量 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]