Research And Improve On Vertical Handoff Trigger And Decision In Heterogeneous Networks

Abstract:With the rapid development of mobile communication and wireless network, a variety of wireless access technologies which can provide different type of service have been put into practice. In order to make full use of the network resources, provide users with support for a various of service needs and ensure the quality of service, the integration of networks becomes the direction of network development. Therefore, the future communication network which can provide different data rates, coverage and support of different service levels will be a heterogeneous network, containing multiple access technologies. As a key technology for mobility management in heterogeneous networks, vertical handoff is used to switch users between different access technologies. Thus, in heterogeneous network, the performance of vertical handoff algorithm is a key factor in the efficient allocation of network resources and the seamless switch of users.Based on the description of the development in mobility management of heterogeneous network and the vertical handoff technologies firstly, this thesis designed a simulation platform which was used to perform system-level simulation for WCDMA and WLAN. It is based heterogeneous network which achieved by MATLAB language. Then, a new vertical handoff algorithm called DPDW was proposed, which include two parts:The first, in handoff trigger phase, two dynamic parameters:the dynamic required SINR DRS and the dynamic monitor time DMT were used to decide every end user’s handoff candidate network set. The second, in handoff decision phase, a new method of computing dynamic weight for a reward function is used by every end user to obtain the weight of three parameters, available bandwidth (B), network delay (D), traffic energy consumption (E) for every network in their candidate network set, and compute the value of reward function, the network with the maximum value of reward function will be chosen by the end user. Finally, simulate the DPDW with two existed algorithms, the simulation result showed that the proposed algorithm has less handoff numbers, less number of dropping and lower energy consumption.The purpose of this thesis is to research the vertical handoff in heterogeneous wireless network. By analysis vertical handoff deeply, a new vertical handoff algorithm called DPDW was proposed, which improved the efficiency of handoff algorithm and the performance of heterogeneous networks. In order to describe the theory and proposed algorithm clearly, this thesis used21images,2tables,66references.