改进的卫星网络多路径并行传输算法

Improved algorithm of concurrent multi-path transfer for satellite networks

针对传统多路径并行传输(concurrent multi-path transfer,CMT)协议无法适应卫星网络高误码特性,提出了一种CMT改进算法。首先,在缓解接收端缓存阻塞的基础上,根据链路中传输的传输序列号(trans mission sequence number,TSN)相对连续的分组时延抖动,正确判断网络的拥塞状况;然后,接收端选取返回时延最短的路径,将拥塞因子及时反馈给源端,源端调节相应链路的拥塞窗口,调整注入网络的数据量。仿真结果表明:本文算法在缓解因卫星链路差异造成的接收缓存阻塞的同时,能够根据网络状况自适应区分拥塞与误码,实现链路的高效利用。相对于传统CMT协议,改进的CMT协议在网络吞吐量、窗口抖动、时延和丢包率等方面都有明显提高。

Aiming at the traditional concurrent multi-path transfer（CMT） protocol cannot adapt to the high bit error characteristics of satellite networks,an improved CMT algorithm is proposed.Firstly,based on alleviating the receiver blocking,the network congestion status is corrrectly judged according to the delay of relatively continuous packet which is numbered by transmission sequence number（TSN）.Then a path with the shortest delay is selected by the receiver and the congestion factor is feedback to the sender.The sender adjusts the corresponding congestive window and the quantity of data injected into the network.Simulation results show that the proposed algorithm achieves good distinction between congestion and error according to network conditions,while the receiver blocking caused by different satellite links is also alleviated.Compared with the traditional CMT protocol,the proposed algorithm can effectively improve performances such as network throughput,window jitter,delay and packet loss rate.