基于CFB模式的802.11e EDCA网络研究  

The 802.11e EDCA Network Based on CFB Mode

作　　者：张南[1] 肖扬[1] 殷慧文[2] 卫婧 

机构地区：[1]北京交通大学计算机与信息技术学院信息所,北京100044 [2]辽宁大学计算中心,沈阳110036 [3]铁道部信息技术中心,北京100844

出　　处：《辽宁大学学报（自然科学版）》2012年第1期64-68,共5页Journal of Liaoning University：Natural Sciences Edition

基　　金：国家自然科学基金No.60572093;国家教育部博士点基金No.20050004016~~

摘　　要：IEEE 802.11 DCF作为无线局域网介质访问层基本协议未考虑优先级,而IEEE 802.11e EDCA协议在数据竞争接入信道时引入了优先级的概念,不同级别的业务流可采用不同的信道接入参数.EDCA机制允许采用CFB(竞争空闲突发)模式,即站点在整个TXOP持续时间内都能对媒体进行控制,可减少竞争信道的时间.不同的业务流在以上三种MAC接入机制是否能得到服务质量保证是本文要解决的问题.本文比较复杂拓扑结构下DCF,EDCA和EDCA+CFB三种模式系统的性能,仿真结果证明EDCA+CFB模式能进一步提高多优先级业务流的服务质量,保证高优先级业务流的吞吐量和丢包率、延迟等性能.IEEE 802.11 DCF is one of WLAN MAC(medium access control) layer protocol which hasn't considered the priority.The IEEE 802.11e EDCA standard introduces different ACs(access categories) and each AC has different priority and channel access parameters.When the CFB(contention free burst) mode for EDCA can be employed,in the entire TXOP time,the access stations can control the connected media traffics which can save some time to compete the channel.However,whether the different priority traffics for their QoS can be guaranteed in above three kinds of MAC layers of network is the problem to be solved in this paper.The access mechanisms of three kinds of MAC layers of network: DCF,EDCA and EDCA + CFB mode are studied,and simulated in the complex topology network,the system performance comparisons under three MAC layers of network are provided.The simulation results reveal that the EDCA + CFB mode can provide multi-priority traffics with QoS support and ensure the system throughput and packet loss rate,delay performance for higher priority traffics.

关 键 词：无线局域网 DCF EDCA CFB QOS 

分 类 号：TN92[电子电信—通信与信息系统]