多速率移动自组网中交叉层优化的性能分析

Performance Analysis of Cross-layer Optimization in Multi-rate Mobile Ad Hoc Networks

由于严格分层的协议无法很好地适应移动自组织网络(Mobile Ad hoc Network,MANET)的动态变化,交叉层设计与优化近年来成为MANET的一个研究热点。针对802.11b标准支持的多速率通信,分别在网络层和MAC层实现了两种多速率控制方案,并通过仿真实验详细分析了这两种速率控制方案的性能。实验结果表明,在网络层引入物理层提供的多速率信息作为路由选取标准,可有效提高网络吞吐率,降低端到端延迟;同时,在MAC层使用高速率转发中继,对网络层路由进行局部优化,可以进一步改善对拓扑动态变化的适应性。

Cross-layer design and optimization in mobile ad hoc networks（MANET） have been the focus of several research efforts in recent years, due to the fact that some inherent issues of MANET cannot be handled well by traditional layered network protocol. The characters of cross-layer processing in 802.1 lb multi-rate MANET were studied in different protocol layers. Using network simulator NS-2 in implementing two types of cross-layer multi-rate control at network layer and MAC layer respectively. Simulation result shows that the combination of routing strategy at network layer and multi-rate information at physical layer can effectively optimize throughput and the average end-to-end packet delay. Moreover, employing relay node at MAC layer to locally optimize route selection may also improve performance of MANET in dynamic scenarios.