无线自组织网络MAC协议公平性分析与改进

对MAP不公平性进行了仿真,发现某些节点由于始终检测到信道繁忙而无法接入信道,建立了一个概率模型,分析了MAP不公平性与MAC协议参数之间的定量关系,指出MAP不公平性是由于一个节点同时暴露于多个冲突域中,当多个冲突域进行空分复用时而引起的.利用概率模型进一步分析了节点获得公平性的条件,并以此为基础提出了一种基于竞争窗口调节的公平性改进方案,仿真表明该方法能够有效解决无线自组网络中的MAP不公平性问题.

Analyzing and improving the MAC fairness in wireless ad hoc networks

There exists severe MAP unfairness in the IEEE 802.11 DCF protocol based multi-hop wireless ad hoc networks.We first study the MAP unfairness by simulation and find some nodes cannot access the channel because the medium is busy all the time.To reveal the unfairness causation we propose a probability model and analyze the quantitative relation between the MAP unfairness and MAC parameters.We find MAP unfairness originates from the exposition of one node to multiple contention areas.We also analyze the fairness condition among the nodes using the probability model and propose a novel fairness improvement scheme based on the contention window adjustment technique,simulation results show its effectiveness to solve the MAP unfairness problem in wireless ad hoc networks.