Abstract
ATM is specified as a standard for multimedia communications, which provides universal information exchange independent of the end system and the types of traffic (data, audio, video). In addition, it is suitable for high speed networks, and provides flexibility and scalability in the network design. Satellite communication systems have also considered ATM as a technology for the global network infrastructure. The role of satellites have changed from purely transparent communication nodes to fast packet switching nodes in the sky. An ATM on-board satellite switch can be seen as a key network entity for the future global communication systems. It is a promising means to increase the bandwidth efficiency and to provide QoS guarantees. But, because the resources of satellite communication systems are limited and more expensive when compared to those of terrestrial systems, the design of an ATM on-board switch needs careful considerations. The long propagation delay, the maximum utilisation of the network resources and the QoS guarantees of multimedia services are considered as the main design parameters. To meet these requirements, a satellite system should employ a robust congestion control scheme. In this thesis an investigation of the congestion control schemes suggested by ATM Forum followed by a new proposal are presented. The new scheme was implemented in OPNET modeller and its performance was evaluated through simulation. The work presented here focuses on the performance evaluation under various traffic conditions.