QoS guarantees for multimedia services on a TDMA-based satellite network

This article describes a proposed network architecture for both the ground and space segments of a satellite network supporting multimedia services with quality of service (QoS) guarantees. The space segment proposal is geared toward a TDMA-based satellite network comprising many nongeostationary satellites, while the ground segment proposal does not put any restriction on the satellite network. The ground segment proposal is based on the new ATM adaptation layer 2 (AALZ) which we consider to have a major role to play in offering an efficient way to provide multimedia services over ATM networks. Indeed, it allows easy encapsulation of the complete set of media component sessions which forms a multimedia transaction into a single ATM virtual channel connection. An additional advantage of AALZ is that it can run over any arbitrary slotted access system independent of the ATM format (i.e., without transporting the ATM cell headers). This is important for efficient interfacing of the ground and space segments. The space segment proposal aims at providing a robust, easily managed and controlled architecture to guarantee QoS by using a combination of connectionless and connection-oriented techniques. This is achieved by: defining a fixed logical network architecture (i.e., independent of the motion of the satellites); limiting the functionality of the switches in the sky; and using adequate addressing and routing procedures.