【作者】 孙芳蕾；

【导师】 曾平；

【作者基本信息】 西安电子科技大学 ， 计算机系统结构， 2004， 硕士

【摘要】 传输控制协议TCP是专门设计用于在Internet上提供可靠的、健壮的、端到端的通讯协议。TCP能在分组丢失率低，且丢失主要由网络拥塞所致的传统网络中获得成功，然而，在有线／无线异构网络的传输中却面临巨大的挑战。 本文在全面综合各类方案，重点分析部分机制后，提出一种新的基于无线TCP的数据链路层解决机制，即簇生丢失重传协议CLRP(Clustered-loss Retransmission Protocol)。该协议中，首先提出一种针对无线链路多分组丢失的检测机制，即选择否定性确认机制SNACK(Selective Negative Acknowledge)。与该机制相结合，CLRP由两个协议组件构成，即运行在基站端的SN-CLRP与运行在移动主机端的SN-TCP，分工完成对无线丢失分组的探测及重传功能。最后，通过原理分析及仿真数据，充分说明了CLRP在数据传输的两个方向上均能有效提高无线TCP的传输性能，特别是在分组丢失率高，突发丢失性强的网络中。更多还原

【Abstract】 Transmission Control Protocol (TCP) is a reliable, robust and end-to-end transmission protocol designed for Internet. TCP can work well on the traditional wired networks where packet loss rate is low and packet losses are mainly caused by network congestion. When running on wired/wireless heterogeneous networks, TCP meets a huge challenge.After synthesizing many kinds of the TCP enhancement schemes and analyzing several of them carefully, a new link layer solution mechanism is proposed, named Clustered-loss Retransmission Protocol (CLRP). In this protocol, a detection mechanism to multiple wireless losses is presented firstly, called Selective Negative Acknowledge (SNACK) mechanism. Combined with it, CLRP consists of two protocol components, which are SN-CLRP deployed on base stations and SN-TCP deployed on mobile hosts, mainly performing the functions of detection and retransmission for wireless packet losses. Finally, according to the principle analyses and simulation results. CLRP can effectively improve the TCP transmission performance over wireless networks, particularly to the networks with high packet loss rate and strong bursty losses.更多还原