The Study On Network Selection Aalgorithm In Heterogeneous Wireless Communication Networks

With the advancing of telecommunication technologies, more and more standards for wireless communication network are developed. The integration between different access networks has become the destined trend of communication networks. And the vertical handover technology with optimal network selection has become a research hotspot.Based on the author's research experience in the NSFC project, the thesis discusses existing international research results on heterogeneous wireless network selection and proposes vertical handover network selection algorithms to cope with scenarios in heterogeneous wireless networks.First of all, the research background and contents are outlined. Then, a brief introduction to the state-of-the-art of heterogeneous wireless network technology is given, including the integrated architecture of heterogeneous network, vertical handover technology, network discovery mechanism and typical network selection algorithms. Furthermore a universal network discovery and selection model is proposed based on the fundamentals of the network discovery selection algorithm. In addition, the capability information of access network is constructed and the mechanism of registration and update of capability information is proposed in light of presence architecture by Open Mobile Alliance. Then, Multiple attribute decision making and cooperative game theory (MGT) based network selection scheme is proposed. The scheme features in calculating the utility value to obtain and sort candidate networks by Multiple Attribute Decision Making from the user point of view, followed by using game theory to calculate the preference value of each candidate network from the network point of view, and as a last step integrating both the user and the network viewpoint to decide on the optimal network. Finally, a system level simulation platform is developed to verify to the MGT algorithm. The simulation results have shown that MGT can not only meet the QoS requirements of different services, but also balance the load of heterogeneous networks so as to maximize the number of admitted users and minimize handoff occurrence frequency.