Abstract: The performance of TCP and the fairness are poor in LEO satellite networks because the difference among the path lengths is evident. A method is proposed to adjust TCP initial congestion window and the increasing speed of the window according to the number of satellites in the path. The new formula of increasing the congestion window is deducted. It is adaptable and can rightly treat different connections respectively. Simulation results show that the performance of TCP is improved effectively, especially when the delay is long. The fairness index is near to 1 when the connections with various delays coexist. The method is easy to implement and compatible with all kinds of TCP versions.

Key words: congestion control, TCP, LEO satellite networks, fairness

摘要： 针对LEO卫星网中不同连接时延差别大、TCP性能降低、公平性较差等问题，提出基于路径中卫星数调节TCP初始窗口和窗口增大速度以改善较长时延连接性能的方法。推导出新的拥塞控制窗口增长公式，区别对待不同时延的连接，具有自适应能力。仿真结果表明，该方法能有效提高长时延条件下TCP的性能，在不同时延的连接间公平性指数接近于1，适用于多种版本TCP在LEO卫星网中的改进。

关键词: 拥塞控制, TCP协议, LEO卫星网, 公平性

CLC Number: 

• TP393