摘要
与传统的有线网络不同,无线多跳Ad hoc网络的拥塞主要表现在MAC层的介质竞争,MAC层与TCP层的跨层设计是提高网络性能的一个重要方法。因此,提出了一种基于MAC层拥塞测度的TCP跨层设计方案,当拥塞指示信号超过设置的拥塞门限,对转发的数据包打上标记并通过ECN机制把拥塞信息经ACK捎回给发送端,发送端据此来调节TCP数据流的发送速率。仿真结果表明了RTS重传次数、帧服务延时和信道忙碌比这些MAC层拥塞测度的可行性和有效性,且网络性能得到较大提高。
Different from the traditional wired networks,the congestion in wireless multihop Ad hoc networks mainly results from medium contention at the MAC layer.A cross-layer design which depends on information of MAC is a new method for improving the performance of Ad hoc networks.Based on researches of congestion metrics from MAC layer over wireless networks,an cross-layer ECN scheme was proposed.The TCP sender will reduce the congestion window based on ECN when forwarding nodes detect that congestion signal is larger than the threshold.Extensive simulations showed that RTS retransmission counter,frame service delay and channel business ratio as congestion metrics were reliable.They can prominently improve transport layer performance in wireless multihop Ad hoc networks.
出处
《桂林电子科技大学学报》
2010年第2期128-131,共4页
Journal of Guilin University of Electronic Technology
基金
广西青年科学基金(0832084)
广西自然科学基金(0832246)
广西重点实验室主任基金(PF090109)
