Satellite ATM is a hot topic on satellite communication field in recent years.TCP over satellite ATM is one of the most important research issues because the long propagation delay of satellite channel can reduce the efficiency of TCP congestion control.Since the congestion control of TCP is implemented by using window

we propose an explicit window indication strategy for TCP over UBR.The simulation results show that this method can enhance the link efficiency greatly and keep good fairness;at the same time it works well under VBR background traffic.It is easy to implement; the buffer size requirement of the gateway for zero cell loss is very small and independent of the numbers of TCP sources.