| The commercialization of multimedia services over wireless and mobile networks appears inevitable in coming years. Two main features characterize the next generation multimedia services: a wide range of customized multimedia applications and the coexistence of different access technologies. This provides great opportunities, yet challenges for the research and development of QoS supports for various wireless access technologies. Although wireless technologies, such as 802.11, 802.16, Bluetooth and IP-based 3G cellular mobile networks, etc., target different markets, better QoS provisioning may make one technology more attractive and competitive over the other. Therefore, QoS is moving towards the center stage of the development of next generation wireless networks. Issues having been addressed in this thesis will play a critical role for the success of the next generation wireless multimedia services and even to the success of the whole IT industry.; In this thesis, the author tackles primary problems of wireless multimedia networks, such as bandwidth management, end-to-end performance, etc. A series of algorithms and protocols are proposed to improve the quality of service for multimedia applications from different domains, including multimedia content, communication subsystem and network. High quality multimedia services can only be realized with the supports and collaboration from all the domains. In the multimedia content domain, the most critical issues are bandwidth scalability and error resilience. We developed a conditional replenishment based coding technique to achieve these features with low complexity. In the communication subsystem domain, we design a SMART protocol to solve the problem of inter- and intra-stream synchronization in wireless networks with large end-to-end delay and jitter. In the network domain, we aim to introduce innovative QoS solutions for IEEE 802.11 based WLAN and multi-hop ad hoc networks. In this part of work, we first propose a unified analytical model that is able to analyze the performance of IEEE 802.11e service differentiation, and thus provides a general guide on mobile station configuration to optimize the network performance. We then propose a technological framework in multi-hop multi-rate ad hoc networks based on cross-layer co-operation. Both solutions in the network domain are aimed to improve the end-to-end performance (i.e., throughput and delay) for multimedia services.; The technological solutions presented in this thesis show the great impetus behind the impressive market demands of multimedia services and applications with QoS guarantees over next generation wireless networks and directly contribute towards the realization of these demands. |
