Network Selection In Heterogeneous Networks

Heterogeneous network is one of the characteristics of next-generation mobile communication systems.The future mobile communication networks will include a variety of wireless access technologies, and which will offer different coverage,throughput and QoS and so on. The complement of these technologies in performance makes heterogeneous network convergence an inevitable trend. In the heterogeneous network environment, the network access selection is to be an important research topic. The methods for how the multi-mode terminal selects the most appropriate and most effective radio bearer in a variety of complex environments, and it will enable the users to maintain accessing to the best network and get the most satisfactory service, also the entire radio resource utilization is up to the maximum.This dissertation describes the convergence of heterogeneous network at different levels and different degrees of integration firstly. The integration of heterogeneous network includes integration in terminals, access network and core network. The current integration programs include tightly coupled and loosely coupled. Also we describe briefly the research status of radio resource management and development status of access selection.This dissertation puts forward different style in different coupled scenarios. Convergence between networks can be divided into tightly coupled and loosely coupled. This dissertation has studied the access selection in the no coupling, loose coupling and tight coupling of the access scenes.As long as there is a coupling between the networks the terminal-secondary network-controlled access style can be used. Then we study network selection architecture and the network selection process in this style.This dissertation also puts forward to two kinds of algorithms using fuzzy multi-attribute decision making. In the network selection process, the application of fuzzy logic is to determine some measure of uncertainty and non-uniform parameter values;the application of AHP is to determine the weight of each attribute based on different service request; for multi-attribute decision-making algorithm that often appears sorted disorder order issue, the improved TOPSIS is proposed; also a fuzzy gray correlation method is proposed for different occasions and service requests.In addition, the dissertation also proposed the use of game theory methods to solve the network selection programs, and a new type of payoff function. Most of the existing network programs only consider single-user access selection cases, but in the actual communication environment, sometimes there are multiple users' requests at the same time, while game theory can be an effective solution to this problem.This dissertation analyzes three different game types of network selection model,puts forward a new expression of the payoff function, you can get a more comprehensive game process involved in players' payoff; it also gives the Nash equilibrium concept and balanced approach for calculating the Nash equilibrium.