一种用于移动自组织网的多址接入动态时延退避策略

A dynamic delay backoff strategy for multiple access in mobile Ad Hoc network

在移动AdHoc网络中,信道接入公平性和吞吐率是MAC协议需解决的重要问题,而IEEE802.11等协议采用的二进制指数退避算法BEB难以满足公平性要求。本文提出了一种基于对节点竞争失败次数(无效RTS)进行计数的方法估计信道争用情况,动态地分配退避计数器初值,从而实现移动AdHoc网络的公平多址接入。研究表明,该接入方法能够有效地反映源节点特性,接入公平性好,同时在高负荷和低负荷的情况下,都能提高网络吞吐量,提供良好的QoS保障。

In mobile ad hoc network, the channel access fairness and throughput are very important issues. Unfortunately, the BEB algorithm used in IEEES02.11 and other protocols cannot meet the practical fairness requirements. In this paper, an strategy based on counting the defeats of node competition （invalid RTS） is proposed to estimate the channel competition and to assign dynamically the initial value of the backoff counter, hence realizing fair multiple access control in mobile Ad Hoc network. Our investigation shows that, the proposed strategy has excellent access fairness and can increase the network throughput, as well as guarantees the system quality of service （QoS）, due to the fact that it reflects effectively the characteristic of the source nodes.