  To meet an increasing demand for multimedia services and electronic
connectivity across the world, satellite networks will play an indispensable
role in the deployment of global networks. The new services gaining momentum
include mobile services, private intranets and high data rate internet access
carried over integrated satellite-fiber networks. Several performance issues
need to be addressed before a transport layer protocol, like TCP can
satisfactorily work over satellite ATM for large delay-bandwidth networks. In
this paper, we review the proposed satellite systems and discuss challenges
such as, traffic management and QoS requirements for broadband satellite ATM
networks. The performance results of TCP enhancements for Unspecified Bit Rate
over ATM (ATM-UBR+) for large bandwidth-delay environments with various end
system policies and drop policies for several buffer sizes are presented.
