Abstract
The increasing demand for broadband multimedia services and their extension to mobiles has spurred provision via satellites. This is because satellite systems can provide a truly global coverage that cannot be economically realised by either fixed wireline systems or terrestrial mobile systems. Most of next generation satellite systems proposed, such as Astrolink, SPACEWAY and SkyBridge, consider using ATM or ATM based technology over satellite to provide broadband services requiring mobility and higher bandwidth. This thesis therefore concerns future broadband satellite networks that use on-board processing and intersatellite links to extend the terrestrial ATM provision to worldwide satellite systems. This thesis discusses the air interface connection management and call handling schemes for integrated mobile/fixed ATM-satellite networks. The prime aim is to research an integrated solution that provides effective radio connection management and mobility support whilst maintaining the required QoS at both user terminals and gateway earth stations. We target at minimising the difference in performance between terrestrial ATM and ATM over satellite and providing mobility extension to the ATM protocols, whilst maintaining a high satellite channel efficiency and keeping as little as possible signalling modifications. In this thesis, an efficient radio connection management scheme, which is designed for a QoS-provisioning transport of ATM traffic over satellite links, and a mobility-enhanced signalling protocol scheme for mobile ATM-satellite networks are proposed. Another large proportion of this thesis is devoted to the optimisations of multiple access and logic link control because these are the major factors that effecting the performance within ATM- satellite integrated systems. As a result, a semi-permanent signalling protocol, a reliability- dependent Selective Repeat Automatic Repeat reQuest (SR ARQ) and an adaptive timer SR ARQ are proposed. In addition to the proposed connection management scheme, a reservation meta-signalling for setting up signalling connections at the user-network radio interface and a mobility-enhanced call handling protocol derived from Q.2931 are proposed. Call control functions such as call routing, location update, paging, handover and authentication are discussed as well. The proposed signalling protocol architecture provides a protocol reference model for ATM-satellite integrated systems. The verification and demonstration of the advantages of the semi-permanent signalling protocol, which offers a new method to improve the system channel efficiency on signalling connections, have been achieved. The proposed reliability-dependent SR ARQ protocol provides a novel approach to optimise the transmission throughput to support a variety of traffic types with different QoS requirements in ATM-satellite systems. The proposed connection management scheme effectively manages the air interface connections for ATM services through diversifying connection types, establishing QoS-based connections and deploying an efficient connection mapping and control scheme. The proposed radio connection management scheme together with the optimised Multiple Access Control (MAC) and ARQ provides a framework of interworking protocols for ATM over satellites. It can also find application in other similar systems that involve the integration of terrestrial protocols and mobile satellites. The research work that has been accomplished herein provides a solution and guidance to the design of signalling protocols for mobile satellite systems to implement ATM technology or indeed other future protocols.