中文摘要：

详细分析了传统的TCP拥塞控制算法在无线多跳网络环境下面临的问题,指出无线多跳环境下的MAC层信道竞争以及TCP拥塞窗口的过激增长机制是影响TCP性能的主要原因,提出一种新的TCP跨层拥塞控制机制TCP-CR.该机制中节点通过MAC层维护的链表信息,将冲突概率定时向源节点的传输层进行反馈,源节点根据获取的反馈信息做出拥塞窗口调整.仿真结果证明,该机制中源节点能有效根据当前MAC层网络状况做出及时动态调整,从而提高TCP的吞吐量.

英文摘要：

In this paper, we have a detailed analysis of the problems when traditional TCP congestion control mechanism encounters in wireless multihop networks. We find that the main reason is medium contention at the MAC layer and overshooting congestion win- dow. We propose a new cross layer solution called TCP based on collision ratio protocol （ TCP-CR ）. Based on this mechanism, a node can feed back collision ratio to its source node periodically through its chain at MAC layer. Thus source node can adjust its congestion window from the feedback information. Simulation results show that our proposed protocol can effectively adjust the amount of out- standing data based on the level of current medium contention and significantly improve the throughput of the network.