Abstract: The bandwidth resource of satellite link is scarce. How to make maximum use of bandwidth resource is an important content of satellite network technology in the current study. The researchers have done a lot of research work on enhancing TCP performance, however, little research has been done on the subject of how to do TCP simulation and how to build simulation platform. The purpose of this paper is to provide a general and flexible method on simulation of TCP connection of satellite link, NS-3 is a new freely simulate software of discrete events for the networks research. This paper simulates TCP connection on satellite link via building simulation scene of satellite link on NS-3, and analyzes 11 kinds of TCP congestion control algorithm in Linux kernel via combining NS-3 with Linux kernel. This paper provides a method of TCP simulation based on NS-3. Readers can simulate TCP connection of satellite link according to this method, of course, can also simulate TCP connection of other scenes. Finally, the simulation results indicate that the proposed methods are correct and resultful.

Key words: satellite communication, satellite link, NS-3 simulation, TCP protocol, congestion control, TCP performance enhancing

摘要： 卫星通信技术一项重要研究内容是如何在TCP连接下最大限度地利用链路带宽。国内外研究人员对 TCP性能改善做了很多研究工作，然而关于如何进行TCP仿真以及如何搭建仿真平台方法研究不多，旨在提供一种通用灵活的卫星链路TCP仿真方法，NS-3是款全新的优秀的网络仿真软件，通过在NS-3仿真软件上搭建卫星链路仿真场景，进行卫星链路的TCP拥塞控制算法仿真；通过将NS-3与linux内核模块结合，仿真分析了linux内核中的11种TCP拥塞控制算法。以此提供了一种基于NS-3搭建TCP连接的仿真方法，可根据此方法仿真卫星链路的TCP连接，同样也可进行其他场景的TCP连接仿真分析。仿真结果证明了提供方法的正确性和有效性。

关键词: 卫星通信, 卫星链路, NS-3仿真, TCP协议, 拥塞控制, TCP加速