The Research On Dynamic Handover Algorithm In The Archetecture Of Heterogeneous Wireless Networks

With the invention of telegram and telephone and the discovery of electromagnetic wave, fundamental changes take place largely in the communication field of human, wired communication and even wireless communication coming out. The wireless communication has come to the third generation up to now, and the fourth is in active construction. Many fast and high efficient access technologies derive from that, such as GSM, WCDMA, WiFi and WiMAX.People demand more than the full use of rich network resource, and hope their mobile terminals can hand over fast to the network of best cost performance in different conditions (time and space), which refers to the dynamic handover in heterogeneous wireless networks. Handover is the groundwork on which users can enjoy service of different networks, and dynamic handover can make mobile terminals access to the best network effectively and quickly. This paper proposes one universal scheme of vertical handover, extending to multiple networks with good scalability.Power consumption is the essential factor to considerate in vertical handover. This paper adopts a service-oriented semi-active handover strategy from the point of the whole network, taking consumption of both mobile terminals and base stations in account. The corresponding handover policy is used in line with features of different networks to reduce the consumption burden of terminals and base stations comprehensively.How mobile terminals hand over freely and correctly among different networks, a good network selection algorithm is needed. Currently, kinds of target network selection schemes with QoS indexes are piled. Though it does some improvement on handover accuracy, massive calculation is not beneficial to energy-limited terminals. This paper presents a location-based network selection algorithm with RSS as a basis, which ensures battery performance of terminals, and guarantees the high rapidity and accuracy of dynamic handover.Besides, it is one of key goals to relieve ping-pong effect for vertical handover algorithm. In that case, this paper describes a prediction mechanism for handover scenes, inspecting the motion trace of terminals adaptively and choosing the relative handover mode to lighten ping-pong effect and make sure the communication quality.The latter part in this paper simulates the process of vertical handover on the platform of Matlab with WCDMA and WiFi as example and verifies the proposed algorithm prevents the occurrence of a ping-pong effect better and enhances more speed and accuracy than the traditional algorithm.