| Abstract |
With rapid progresses in mobile computing technologies, the integrated and ubiquitous computing environment has been developed into Telematics services, which focuses on the safety, entertainment and information of vehicles. Vehicular ad-hoc network (VANET) is one of well-known environments where Telematics is applied. Compared with personal computers, the communication capability of on-board devices in vehicles is still limited due to their high mobility. Therefore, how to efficiently utilize the limited communication capability of an on-board device is one of the main challenges on Telematics. To improve the service quality of Telematics, the coordination between wired networks and mobile networks becomes more and more important. However, some features in VANET such as low-bandwidths, high jitters, high packets loss rates and so on make it difficult to guarantee service quality. Furthermore, inter-vehicle communication is short range transmissions. Links between vehicles are difficult to maintain. How to ease the impact of intermittent communications is one of major issues in VANET. This dissertation focuses on the multimedia streaming service for the VANET and proposes a mechanism to improve the service quality of multimedia streaming. The novel mechanism named “QoS control mechanism for multimedia streaming services in VANET” is proposed in the dissertation, which is comprised of four sub-mechanisms: (1) Multimedia QoS Adaptation Module: It makes decision for the adjustment of QoS request based on available bandwidth and resource constraints on the mobile devices; (2) Network-Aware Transmission Adaptation Controller: Layered-coding scheme is employed and base layers and enhancement layers are well scheduled based on their individual features; (3) Bi-directional Routing Protocol for V2V Communication: fast route discovery and local repair routing protocol is proposed to improve the performance of multi-hop V2V communications, and (4) Cooperative Transmission for V2R Communications: involving buddy vehicles with the consideration of collisions to improve the total throughput in a RSU. |
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