Research On Vertical Handoff Decision Algorithm In Heterogeneous Wireless Network

With the rapid development of mobile communication technology, the nextgeneration mobile communication system will be the heterogeneous wirelessnetworks, where a variety of access technologies coexist. The networks coveroverlapping, complementary advantages, so as to provide users with the best accessservice. As an important part of mobility management, the vertical handofftechnology that ensures the users can acquire the best service quality has become oneof the most challenging key technologies in heterogeneous network.This paper analyzes some typical vertical algorithm: based on the received signalstrength, simple additive weighting and multiplicative exponent weighting, techniquefor order preference by similarity to an ideal solution, grey relational analysis, andanalytic hierarchy process. For these deficiencies and heterogeneous environmentscharacterized by dynamic network conditions. This paper introduces the applicationof fuzzy logic method for vertical handoff in heterogeneous wireless network. UMTSand WiMAX are two kinds of typical wireless access mode, this paper studied verticalhandoff based on communication simulation scenario which established by the twokinds of networks.According to the different business type and user requirement, this paper putforward an improved vertical handoff algorithm. The algorithm can be divided intotwo stages: the pre-decision stage and the ifnal decision stage. In the pre-decisionstage, the algorithm uses the fuzzy logic approach, which can reduce the ping-pongeffect by the cause of dynamic change of network condition. In the ifnal decision stage, the cost function is used to weighted decision factor. This can guarantee thequality of customer service while also consideration of user preferences. This papercarries out simulation analysis for the provided vertical handoff algorithm, the resultsshow that the proposed algorithm can select the best access network according to thedifferent business types and service requirement, and effectively reduce the ping-pongeffcct and power consumption.