Research On Robust Handoff Algorithm In Heterogeneous 5G Networks

With the commercialization of 5G wireless networks,it is bound to form more complex heterogeneous 5G network environments with the existing wireless networks.In this environment,various wireless network technologies overlap with each other,which can increases the interference between networks and the complexity of network handoff.Therefore,how to improve the robustness of algorithm and select a network that meets the demands of mobile terminals in heterogeneous 5G network environment has become a hot issue.This thesis improves algorithm robustness and user satisfaction from the parameter fluctuation and terminal demand respectively.The main work of this thesis is as follows:1.In the heterogeneous 5G networks,a robust vertical handover algorithm based on interval mark decision is proposed,target to the problem of low handoff accuracy of current handoff algorithm due to the poor robustness.Firstly,the median average filter method is used to obtain more accurate network attribute values.Secondly,based on the analysis of parameter fluctuation characteristics,an interval mark decision algorithm is proposed to guarantee the candidate network screening pass rate and accuracy,and improve the robustness of the interval mark decision algorithms.Thirdly,according to the transmission layer requirements of the mobile terminals and the trend of the mobile terminals motion,the utility function of different weights is used to obtain the best target network.Finally,the simulation results show that the algorithm can effectively improve the accuracy of handoff and system throughput,reduce the failed handoff and the pingpong effect,and choose the best target network through the demands of mobile terminals.2.Although the above algorithm has improves the handoff accuracy from the perspective of reducing noise interference,it ignores the problems of unnecessary handoff and uneven load causing by overlapping coverage of networks with different coverage radii and network performance differences.Therefore,a vertical handoff algorithm base on adaptive terminal demand is proposed.Firstly,according to the relationship between network performance and terminal demand,a handoff level evaluation algorithm is proposed to calculate the handoff factor,which can reduce unnecessary handoffs and meet the demands of the terminal.Secondly,the network performance gains after handoff are calculated,and the accuracy of network performance gains is increased by predicting the switching state of mobile terminals at the next moment.Again,the handoff factor and network performance gain are used as the input of the optimized fuzzy logic to obtain the output value for the final handoff decision.Finally,the simulation results show that the algorithm can trigger handoff according to the terminal demand,enhance the stability of network service,balance the network load,and improve the overall performance of the system while improving the terminal demand satisfaction.Finally,simulations show that the algorithm triggers switching based on terminal demands,enhances the stability of network services,and improves the overall performance of the system while ensuring terminal satisfaction.