Research On Access Network Selection Algorithm In Multi-terminal Coordinated Network

With the evolution and development of communication network technology and mobile terminal devices, the users have more choices on terminal and network selection to launch a service. The users can not be satisfied with the service quality brought by single terminal and single network. In order to overcome the bottleneck of single wireless access technology, to make full use of terminal and network resources to improve the service experience of users, multi-terminal coordinated communication comes out in this context. It receives much attention of information and communication field as an important branch of ubiquitous networks. In multi-terminal and multi-network environment, it is a key issue to select appropriate terminals and access networks to collaboratively provide best services for users, also it is the main content of this thesis.In single-user and multi-terminal coordinated application scenario, the whole multi-terminal coordinated communication network architecture is studied in the thesis, which is based on the ubiquitous network. The multi-terminal coordinated service platform of the network architecture integrates, controls and manages terminal and network resources. The function of each layer of the network architecture is discussed. Four main function modules of the service platform and the information interactive process among them are designed and discussed in detail. Then the thesis makes a deep study on the network selection algorithm in multi-terminal coordinated network, which includes the following two parts of contents.Firstly, the existing network selection algorithms do not fully consider the user preference information, also the calculation of network parameter weight is too subjective. For this situation, the user-preference based network selection algorithm is proposed in the thesis. The algorithm fully considers service requirements, user preference and network performance to calculate network parameter weight and network preference weight, then optimal access network is selected. Simulation results show that the user-preference based network selection algorithm could select proper access networks which satisfy the service requirements and user preference. Also compared with the traditional network selection algorithms, it reduces the number of handoff times as the user moves through the network boundary frequently.Secondly, it is a key issue to select suitable terminals and its corresponding access networks instantly in multi-terminal coordination mechanism. Then terminal and network cooperative selection mechanism is proposed in the thesis, which combines the terminal selection and network selection. The mechanism puts forward to integrate terminal and its access network as a virtual terminal unit. With the design of terminal and network cooperative selection algorithm, more than one virtual terminal unit would be selected to form a cooperative terminal set to provide services. Simulation results show that the cooperative terminal set selected by the proposed cooperative selection algorithm can effectively help to save energy consumption of terminals as well as ensure the data rates.With the research on terminal and network cooperative selection algorithm, terminal and network resources around users are fully utilized. It provides users with high quality, personalized, intelligent services and improves users’ service experience.