基于 CTCP 的动态调整拥塞控制算法

摘要

Space network has some characteristics , such as long transmission delay and high packet loss rate , which lead it diffi-cult to use ground routing protocols in space network completely .CTCP is a new transport protocol using network coding technolo-gy, and experiment shows that its performance in space network environment is better than TCP ’s.However, CTCP’s congestion control mechanism is similar to TCP-Reno’ s, which congestion window is set statically , causes the result that the performance of CTCP’ s congestion control in the complex network environment is not ideal .This paper presents a dynamically adjustive conges-tion control algorithm H-CTCP based on CTCP , which in real-time estimates the available bandwidth in space network , and dy-namically sets the congestion window .Experimental results indicated that the improved congestion control algorithm H -CTCP is more suitable in space network of high packet loss rate , and increased transmission performance .%空间网络具有传播延时长、信道丢包率高等特点，使得传统的地面路由协议TCP协议难以适应于空间网络。 CTCP是一种结合网络编码技术的新型传输协议，实验表明在高丢包率的空间网络环境中的性能要优于传统的TCP协议。但由于CTCP的拥塞控制方式类似于TCP-Reno，拥塞窗口的调整是静态设定的，使得CTCP的拥塞控制机制在多变复杂的空间网络环境效果并不理想。本文提出一种基于CTCP的动态调整拥塞控制算法H-CTCP，通过对空间网络中的可用带宽进行实时估算，动态设定拥塞窗口。实验证明，改进后的拥塞控制算法更能适应高丢包率的空间网络环境，大大提高CTCP的传输性能。