基于星上处理的卫星ATM中ABR业务拥塞控制算法研究

The Research on the ABR Congestion Control Algorithm in Satellite ATM Based on Onboard Processing

卫星ATM是近年来通信领域的研究热点 ,拥塞控制是其中很关键的一个问题 .本文主要研究基于星上处理的卫星ATM网的ABR流量控制 ,它通过对流量的长时预测来达到控制目的 .由于卫星信道的大延时 ,无法实现精确的长时预测 ,因而将预测结果直接用于ABR的拥塞控制效果不甚理想 .将长时预测同动态利用因子控制的方法结合之后 ,在链路效率、信元丢失率、不同连接数目和暂态响应等方面都取得很好的结果 .

Satellite ATM(Asychronous transfer mode) is a hot research area of satellite communication in recent years and congestion control is one of the key issues.This paper focuses on the ABR(Available bit rate) congestion control algorithm in the satellite ATM network based on onboard processing,which is implemented by using the traffic prediction.Owing to the long propagation delay of satellite channel,the accuracy of prediction decreases and it degrades the performance of ABR congestion control.In order to overcome the impact of inaccuracy,a new method ‘Long time prediction plus dynamic control bandwidth utilization factor’ is suggested.Simulation results show that this method has advantages on the cell loss probability,link usage,fairness,adaptation to different number of TCP(Transport Control Protocol) sources and transient response.