无线Mesh网络MAC层DCF机制的研究及改进

摘要

To cope with the deficiency that the IEEE 802. 11 DCF in wireless mesh networks deploys all the nodes in the same way and cannot dynamically adjust their contention windows according to their real time status, the authors divides contention window into initial contention window, successfully sent window and conflict contention window. This scheme designs three different back off algorithms for the different windows so that dynamically adjusts the ability of nodes to accessing channel in different status and improves the fairness and throughput of network.%无线Mesh网络传统的IEEE 802.11接入控制协议DCF(Distributed Coordination Function)不能有效解决公平传输问题,提出了一种基于接入公平性的自适应分布式协调机制ADCF(Adaptive Distributed Coordination Function,ADCF),根据节点的实时状态,设计了节点在初始竞争,成功发送数据后和发生冲突时的退避算法,动态地调整了节点在不同状态时的信道获取能力,提高了节点发送数据的公平性和网络的吞吐率.最后用NS-2进行仿真表明,ADCF机制能显著提高节点发送数据的公平性,增大网络的吞吐率以及减小数据包的平均端到端时延.