无线移动网络中增强TCP性能的技术综述

AN OVERVIEW OF MECHANISMS FOR IMPROVING TCP PERFORMANCE OVER WIRELESS MOBILE NETWORKS

TCP是因特网上的主要传输协议,在数据包丢失主要是由拥塞引起的传统网络上,TCP可以充分发挥其性能,但是在无线移动网络中,TCP将无线信道比特差错和移动切换引起的数据包丢失误归于网络发生拥塞而采取拥塞控制措施,不必要地降低了端到端的吞吐率,导致自身性能的下降.首先简述了当前无线移动网络的发展状况和TCP面临的问题.在此基础上,综述和评价了各种增强TCP性能的技术方案.最后,结合无线移动通信系统的最新进展,分析和探讨了当前存在的问题和进一步的研究方向.

In the Internet, TCP is the dominating transport protocol tuned to perform well in traditional networks where congestion is the primary cause of packet loss. However, wireless networks also suffer from significant losses due to bit errors and mobile handoffs. TCP responds to all losses by invoking congestion control and avoidance algorithms, resulting in the degraded end-to-end performance unnecessarily. Firstly the recent development of wireless mobile networks and the problems with TCP are introduced. Then the survey and evaluation of mechanisms proposed to enhance TCP performance in wireless networks are presented. Finally, based on the tendency of wireless mobile telecommunication systems, the current problems and the challenges of future research are discussed and analyzed.