Fuzzy Multiple Attribute Access Selection Scheme In Heterogeneous Wireless Network

In the future, the wireless mobile communication technology, intelligent terminal and business applications will form a broad market space. It is an important driving force for the global communications industry. And our national major projects have clearly requirements that we must regard mastering the core technology of mobile communication and independent intellectual property rights as the breakthrough of enhancing the core competitiveness of China’s telecommunications industry. In recent years, our country has emerged a variety of wireless access technologies, such as CDMA2000, WCDMA, TD-SCDMA, TD-LTE and FDD-LTE. Moreover, mobile operators have introduced wireless networks like CMCC, China-Union and China-Net to meet the users’ need for low-cost and high rate access experience. These wireless networks enable that anybody can enjoy high-speed, high-quality communications services experience at anywhere. However, the communication terminal consists of computer, network device and system made by different manufacturers, so it runs at different protocols to support different features or applications. To ensure high-quality communication services and users’ seamless access, how to choose an optimal access network became an important research proposition.The vertical handover technology is the key to achieve effective integration of heterogeneous wireless networks. Currently vertical handover technology is still in the theoretical stage. As it relates to different carriers and network architecture, applying the conventional switch technology to heterogeneous wireless networks has lead to a high dropout rate and handoff delay. Therefore, it is urgent to research a more flexible and efficient vertical handover mechanism and performance optimization algorithm, which meets the dual needs of mobile users for high transfer rates and high business experience. This paper studies the vertical handoff technology on multi-mode mobile terminal in heterogeneous wireless network. It integrates a fuzzy hierarchy analytic process and an adaptive filtering method with the end-to-end connection management, so as to reduce the packet loss rate during vertical handover, handoff delay and improve the radio resource utilization. The main research contents of this paper include:Aiming at the selection of decision factor in the access selection algorithm of heterogeneous wireless network and limitations on normalized processing and decision matrix dynamic prediction, this paper presents a dynamic decision matrix normalization method. Firstly, it chooses a suitable normalization function according to different characteristics in decision-making factor. Then it establishes and predicts a dynamic decision matrix by an adaptive filtering method. Lastly it optimizes to improve the accuracy of normalization network parameters and reduce operation load of the mobile terminal. In addition, the algorithm can guarantee the accuracy of decision results under a continuous changing environment in heterogeneous wireless networks, and we build an access control demo platform to verify the performance of the algorithm based on simulated mobile terminal. The experiment results show that the algorithm can independently select an optimal network and access it on the condition of meeting service’s requirement, user’s preferences in the actual network situation. And it reduces the requirement of calculation capacity in algorithm for terminal. It enhances the experiment result’s accuracy and stability under a continuous changing environment in heterogeneous wireless network and eliminates the easily caused “ping-pong” effect by access selection algorithm in terminal.