Research On Vertical Handoff Strategy Based On Media Independent

With the fast evolution of mobile communications, mobile users will more likely face the environment in which a diverse number of wireless networks coexist. Besides, the development of multimode terminals and diversified user demands has strengthened the concept of heterogeneous networks. Further, the fourth generation of mobile communication network is aiming at integrating the resources of heterogeneous wireless networks and offering seamless services. To accomplish integration and inter-working among heterogeneous networks, the universal seamless handoff technology is a key point and remains a challenging problem.This paper focuses on the problem of vertical handoff decision mechanism in heterogeneous networks in the following two aspects:1、an application scenario of the integration of heterogeneous networks;2、 vertical handoff decision algorithm based on the application scene of the heterogeneous network integration.First of all, this paper makes the research on the theory of heterogeneous network handoff and the protocol module of multi-mode terminals in wireless heterogeneous networks. And then we analyze the new characteristics of vertical handoff and summarize existing vertical handoff decision algorithms.Secondly, this paper focuses on the research on the vertical handoff protocol structure analysis and the research on802.21protocols. Then we propose an application scenario of the integration of heterogeneous networks based on media independent handoff. In the fourth chapter, we will propose a two-step adaptive service vertical handoff decision algorithm based on dynamic weight compensation, from the view of the user performance first. The experimental results show that our algorithm outperforms the traditional algorithm by increasing the consistency of decision matrix, fully taking advantages of the range of network choices and reaching a better load balance of the whole wireless environment.And in the fifth chapter, we will put forward new handoff parameters, new handoff blocking probability and the lowest pre-handoff blocking probability. Then we will propose a smart vertical handoff decision algorithm based on queuing theory from the aspect of load balancing, the experimental results show that the proposed algorithm outperforms the traditional algorithm with low handoff blocking probability and a better load balance of the whole wireless environment.