【摘要】 无线Mesh网上机会路由协议是一个研究热点.现有机会路由协议大多采用固定速率数据发送方式和端到端数据应答方式,因而产生了网络拥塞和大量数据重传等问题.该文针对以上问题提出一种建立在机会路由内部的速率控制方法,同时引入一种循环轮转的数据发送方式.文中提出的速率控制方法充分考虑了无线链路的质量和机会路由无固定传输路径的特点,通过比较本地和邻居的数据"实际"缓存长度来检测局部网络的拥塞状况,调节各节点的数据发送速率以达到拥塞控制的目的.循环轮转的数据发送方式在保证数据传输可靠性的同时减少了由于应答数据丢失造成的不必要重传,从而提高了端到端的数据吞吐量和资源利用效率.仿真实验表明,与具有代表性的机会路由协议MORE相比,改进后的机会路由协议在多种场景下均获得明显的性能提升.更多还原

【Abstract】 Opportunistic routing(OR) has attracted increasing attentions,and several practical protocols over wireless mesh networks(WMNs) have been proposed.Opportunistic routing protocols usually use a fixed rate to send data packet and end-to-end acknowledgement to ensure reliability,which cause congestions and duplicated retransmissions in the networks.In this paper,we propose a built-in rate control mechanism in opportunistic routing to avoid performance degradation due to network congestion.It takes full consideration of the wireless link quality and the non-deterministic multi-path characteristics of opportunistic routing.We also introduce a round-Robin packet sending fashion to reduce unnecessary retransmissions and improve throughput. Simulations show that the modified protocol significantly outperforms the state-of-the-art opportunistic routing protocol,MORE,in both single and multiple flow scenarios.更多还原