Study Of Network Selection Strategy And Handover Management Mechanism In Cognitive Radio Network

This paper mainly studies the network selection strategies and handover management mechanisms under cognitive wireless network environment, and their applications in resources mobility scenario. Firstly, the basic concepts, research contents and development status of cognitive wireless network and the cognitive radio resources management structure are introduced. Based on these, the concept of resource mobility is introduced and the reasons lead to resource mobility are analyzed, also the network selection strategy and handover management mechanism are pointed out as two main research contents of resource mobility management. Afterwards, based on studying the existing network selection strategies which are used in heterogeneous network environment and considering that the characteristics of network traffic load are always varying with time, we propose an improved network selection strategy and present its corresponding simulations and analyses. Then, this article studies the handover management mechanism during user's movement with the emphasis on how to determine the optimal handover trigger time, and puts forward an improved handover trigger time selection method. This method synthesizes handover time delay estimation and auto-regression model prediction technology to determine the optimal time for the user to trigger handover process. Simulation results show that under the situation of network coverage varying with space, this method can effectively reduce the handover failure probability and ensure service continuity during handover.