| dc.description.abstract | By the rapidly evolving mobile communication technologies, broad transmission bandwidth and sophisticated Quality of Service guarantee mechanisms enable plenty of multimedia applications. Today, multimedia contents have dominated the consumption of wireless communication network resources. Providing suitable access technologies to smooth subscribers’’ experiences in multimedia service consumption is much crutial.
In fact, mobile communication networks bring mobility to mobile subscribers and win significantly success in modern communication markets. The mobility provides session continuity to mobile subscribers and assists them to obtain some level of ``smooth’’ to their consuming applications. However, seamless handover has still been one of the main issues to provide service smoothly to mobile subscribers.
Toward the next generation multimedia communication, all-IP core networks and heterogeneous access networks would construct ubiquitous multimedia communication environments. The Next Generation Multimedia Network (NGMN) would provide not only session mobility, but also service mobility to subscribers. The ubiqutous communication enables multimedia subscribers access their interested multimedia services using anydevice at anytime, in anyplace. The mobility becomes more flexible but knotty.
The 3rd Generation Partnership Project proposes IP multimedia subsystem to build the NGMN. The IP multimedia subsystem is an integrated platform for developing and deploying multimedia applications speedy and easily. It overlays heterogeneous access networks, including fixed and mobile ones, to support service mobility to subscribers. Thus, heterogeneous handover is unavoidable but much difficult while one considers smoothly services. When investigating the mobile services in the IP multimedia subsystem, we find that the services suffer from several handover latencies. The latencies prevent various of multimedia services which are usually real-time from serving smoothly. In addition, inconsistent Quality of Service policies and distinct mechanisms between heterogeneous access networks corrupt the smooth, besides varing channel conditions.
In this dissertation, we invoke the scalable video coding (SVC) scheme to provide streaming video services over the IP multimedia subsystem. The scalable video coding scheme utilizes layered-based technology to overcome the inconsistency between heterogeneous access networks and radio channel conditions. The scheme can support smooth services to mobile subscribers in its design spirit, however, the existing Open Systems Interconnection (OSI) model-based networks hide the efficiency. This dissertation, thus, first exposes the importance of the SVC-encoded video data to existing OSI-based network nodes. By the exposure, the network nodes can successfully perform conscientious protection to more important parts of SVC-encoded video data, and invoke the scalability of the SVC scheme to obtain smooth service from application aspect. Furthermore, this dissertation introduces Media Independent Handover (MIH) service to the IP Multimedia Subsystem, and proposes a Fast IMS Service Recovery Mechanism (FISERM) to mitigate handover latencies in heterogeneous access networks. The Media Independent Handvoer service assists mobile subscribers to handover between mobile access network smoothly. In addition, this dissertation invokes the MIH service to achieve seamless servoce. In fact, seamless service is preferred rather than seamless handover in the design of FISERM. The seamless service considers not only lower-layer handover procedures between heterogeneous access networks, but also application layer handover that the IP Multimedia Subsystem invokes for service mobility and Quality of Service guarantee.
Finally, this dissertation proposes an active seamless service scheme to the SVC streaming video services over IP multimedia subsystem. The active seamless service scheme get really seamless service to SVC streaming video services by an advanced buffer filling strategy. The strategy fills the service gap that starves the video buffer of the streaming video services and disturbes the playback. System simulations evidence that the proposed schemes provide outstanding performance to the real-time multimedia service over the IP Multimedia Subsystem, expecially for Scalable Video Coding streaming video services.
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