Research On Key Technologies Of Service Convergence

With the continuous development and evolution of network technologies and capabilities of terminals, the service boundaries among telecommunication networks, Internet networks and television networks have gradually vanished, and a lot of new services have been derived for each kind of networks. However, the service requirements from users have gradually changed, from simple voice communication to multimedia information interaction, from single network single terminal access to multi-network multi-terminal access and multi-device cooperative communication, from unified service delivery to intelligent personalized service delivery. Therefore, developing a new converged service with capabilities of multi-network multi-terminal access and environment-aware has become an inevitable trend.In this dissertation, the author researched systematically some key technologies of service convergence, including architecture of service convergence, framework and model of information convergence, cross-device mobility and continuity of converged service, and the transfer efficiency of real-time media streams over radio access network environment. The main contributions of the dissertation are as follows:1. Traditional communication services were designed independently according different service architectures, service capabilities could not be reused, and the service experience is simple. So, this dissertation proposes a new converged service architecture. This service architecture is built as horizontal layers and components, supporting the convergence of a variety of service enablers and media types, supporting the collaborating communication of multiple devices, supporting cross-device service mobility and continuity, supporting dynamical reuse of service components, with context-aware capabilities, and with the abilities of intelligent and personal service delivery.2. In current network and service environment, user information supporting the converged service enablers is usually stored dispersedly, and the content of user information is usually redundant and inconsistent. Therefore, the quality of service is usually bad. This dissertation proposes a centralized model and framework of converged user information, and a unified user-centric information association model, a unified semantic-based information storage model, and a push-based dynamic awareness model of user information. This model and framework has obvious advantages in efficiency of information query, information consistency and integrity, network traffic, service providing delay, service accuracy and intelligence, etc. It addresses the performace problems that may exist and the scalability issues of converged service system, therefore enhances the user’s service experience.3. Studies systematically the cross-device service/session mobility and continuity of converged service. A framework and scheme of cross-device service/session mobility and continuity is proposed, which includes a service mobility mamagement server and a context-aware repository. The mobility control mechanism and methods are specified. Based on queuing theory, a network model is built for the behavior of across-device service/session mobility in converged service. The delay of cross-device service/session mobility is evaluated by theoretical analysis and simulation. It shows that the proposed cross-device service/session mobility solutions can ensure session continuity during cross-device mobility, mobility delay is short, and user’s service experience is better.4. For the speciality of WLAN broadband wireless access network, a multi-state auto-adaptive voice frame combination model is proposed, which can improve the efficiency of voice streams. The model considers multiple STA competing, MAC layer retransmission mechanism, the signal to noise ratio of physical channel and other factors, which can adjust automatically the length of the application layer combination of voice frames according to the real-time changes of WLAN network environment. Therefore improves the transmission efficiency of real-time voice streams in WLAN network. Theoretical analysis, simulation and experiments have proved the validity of the model.