Research On Vertical Handover Algorithm For Integrated 5G And WiFi Networks

5G,the next generation wireless mobile communication system,should outperform the traditional cellular network in terms of metrics such as transmission rate,system capacity and spectrum utilization.However,with the increase of data traffic,a kind of wireless network cannot meet the growing of users' requirement.Therefore,the future mobile network will be a heterogeneous form which consist of variety of wireless networks.Vertical handover is a key technology in heterogeneous network,which becomes a research focus in academic field.With being widely used of WiFi,how to choose the best network to perform seamless handover is one of difficult problem in integrated 5G and WiFi networks,then a good handover scheme becomes very important.This paper focuses on the vertical handover algorithm for 5G integrated network.The main research work and innovative achievements are as follows:Firstly,the technological evolution of 5G and WiFi is expounded.Then the technical requirement of heterogeneous network is introduced.Meanwhile,the vertical handoff technologies in heterogeneous environment are summarized,including some typical vertical handoff algorithms.Secondly,based on the MADM algorithm,in order to resolve the disadvantage of monolithic handover decision system(HDS)sequentially processes switching parameters only by one method,a new handoff algorithm based on modular multi-attribute decision making(M-MDAM)is proposed.This algorithm based on the modular HDS design,and the handover parameters are classified into NQ module,UP module and DS module.Then,based on traditional TOPSIS and fuzzy theory,the NQ module and UP mudule are completed simultaneously.According to the output of DS module,candidate networks are ranked and chosen.The simulation results show that the proposed M-MADM algorithm can solve the problem of long computation time and poor performance of network selection,avoid the Ping-Pong effect.Thirdly,in order to solve the problem of severe mobility management in integrated 5G and WiFi networks,a vertical handoff scheme based on moving speed prediction is proposed to choose the appropriate network for users.First of all,the Gauss Markov mobility model is used to estimate the trajectory of users,determine the users' location and whether it meets the pre-decision conditions.Then,the maximum handoff failure probability and unnecessary handoff probability is used to get the marginal velocity.Finally,choose the appropriate network dynamically according to users' estimated speed.Simulation indicates that the proposed algorithm can effectively reduce handoff failure probability and unnecessary handoff probability,comparing with traditional algorithms.This paper deeply studies the problem of vertical handover for integrated 5G and WiFi networks,and works out some meaningful research results,which will provide some theoretical values and practical meanings for the design and implementation of 5G heterogeneous networks in the future.