Research Of Network Selecting Algorithm In Heterogeneous Wireless Networks Based On VAS/MADM

With the development of network technology and the popularity of multi-mode mobile terminals, the applications of wireless mobile communication become more extensive. The diversification of networks, terminals and QoS of traffic, demands higher for seamless handover under the heterogeneous network. Selecting the most appropriate and ideal wireless network for the terminals whenever and wherever to ensure the quality of services, is one of the key technical problem in heterogeneous network integration and mobility management. So the network selection algorithm for vertical handoff is the main research content in this article.Firstly, after the survey and research of review and relevant issues about VHA and network selection algorithm, the article sorts out the related concepts and technology of vertical handover in heterogeneous network, including handover processes and involved parameters. After that, the existing algorithms are classified and introduced, whose notion, characteristics and limitations are summarized.Then, in view of the problems and shortcomings commonly existed in the current algorithms, a new network selection algorithm based on variable attribute system is proposed to meet the requirements of an ideal algorithm. The VAS/MADM makes improvement from traditional MADM algorithm in many aspects, from the process to details. To improve the incompleteness and inflexibility of the original attribute system and the contradiction between attributes, the algorithm deals with the decision attributes in advance, fully considering the various attributes in terms of the network and terminal conditions and eliminating the influence of meaningless attributes on the results. Meanwhile, the complexity of the follow-up process is reduced so that it improves the feasibility of the scheme.Finally, the system simulation model is built in Matlab/Simulink platform, in which several function modules execute different processing, allocation and data analysis for the algorithm. To compare the new algorithm proposed in the article with traditional ones, both of their models are simulated. The parameters and mathematical model is according to the relevant protocol standards and documents. The simulation results show that compared to the traditional ones, VAS/MADM can take more accurate and effective decision to optimal network, with lower handoff times and greater improvement in both user satisfaction and system performance. So it can be a reference for research in the seamless handover in heterogeneous networks.