海上船舶网络中TCP协议性能分析

摘要

According to the characteristics and the service demanding of the maritime ship networks, the main factors that affect the transmission performance of the Transmission Control Protocol(TCP) in the wired and wireless hybrid networks is analyzed, and the survey is concentrated at the effect of Mobile Ad hoc Networks (MANETs) that have some inherent limitations among the ships, which causes the lower efficiency of the tradi-tional TCP. Based on the analysis and comparison of several hot schemes to improve the performance of TCP in MANETs, a solution for data transmission based on TCP in the wired and wireless hybrid maritime ship networks is proposed. This solution is end to end, and it includes wired part, access server and wireless part. Standard TCP is adopted in the wired part. The modified TCP or UDP is adopted in the wireless part, which aims to improve the performance of TCP in MANETs. The access sever which had protocol conversion function connects the wired and wireless parts. The simulation results based on QualNet simulator shows that the throughput of the improved scheme increased obviously, compared with the traditional TCP.%根据海上船舶网络的特点及其业务需求，深入分析了该有线/无线混合网络中影响TCP（Transmission Control Protocol ，传输控制协议）传输性能的主要因素。其中，着重研究了船舶间MANETs(Mobile Ad hoc Networks,移动自组织网)的影响，该网络存在一些固有局限，使得传统的 TCP 协议应用于其中时效率低下。在分析对比目前业界改进 MANETs中 TCP性能的一些热点方案的基础上，提出了一种海上船舶有线/无线混合网络中基于 TCP的业务传输解决方案。该方案是一种“端到端”的解决方案，包括三部分：即有线部分、接入服务器以及无线部分。有线部分采用标准的 TCP协议；无线部分采用改进的 TCP协议或者是UDP协议承载，以改善TCP协议在MANETs中的性能；接入服务器连接有线和无线部分，具有协议转换功能。利用QualNet进行仿真分析，结果表明，与传统TCP协议相比，该改进方案吞吐量有显著提高。