Research On Optimized Vertical Handoff Algorithm For Improving User Experience In Heterogeneous Wireless Network

With the rapid development of wireless communication technology,various wireless technologies keep emerging.The next generation wireless networks will be composed of multiple wireless access technologies,which can provide multiple access modes and support the seamless and transparent roaming of the terminal heterogeneous wireless network.In the heterogeneous wireless networks,how to ensure that users switch to the best network reasonably and accurately has become a hot issue in academic research.The current vertical handoff decision algorithm based on artificial intelligence improves the performance of the system,but at the same time increases the complexity of the system,thus affecting the user experience.Aiming at improving user experience in vertical handoff,this paper first proposes an adaptive vertical handoff algorithm based on artificial neural network in combination with type of service,and then proposes a hierarchical vertical handoff algorithm based on fuzzy logic in combination with network and user.Both optimize the complexity of the algorithm and reduce the time cost,thus improving the user experience.The main work of this paper is as follows:1.Current research on vertical handoff algorithm based on artificial neural network has a poor service adaptability and high computational complexity.Considering this problem,an adaptive vertical handoff algorithm based on artificial neural network is proposed.The main idea is: firstly,according to the Received Signal Strength obtained by the terminal,a method of thresholding is used to select a candidate network set.Secondly,in terms of the different types of services classified in this paper,the parameters are normalized and adaptively selected.Thirdly,the selected parameters are input into the artificial neural network to choose the best access network from the candidate network.Finally,the experimental results show that the algorithm can reasonably select the handoff network according to the user's service type,meet the needs of different terminal services,reduce the handoff blocking rate,increase total network throughput and lower the time complexity of the algorithm.2.The parameter weight is difficult to determine for the vertical handoff algorithm considering the parameters of the network and the user,at the same time,the vertical handoff algorithm based on fuzzy logic has high complexity.Considering this problem,a hierarchical vertical handoff algorithm based on fuzzy logic is proposed.Firstly,the received signal strength,bandwidth and delay are input into the first-level fuzzy logic system.Combining with the rule adaptive matching,the QoS fuzzy value is inferred,and the network is initially filtered by the QoS fuzzy value to obtain the candidate network set.Then,the second-level fuzzy logic system is triggered by the trigger mechanism,and the QoS fuzzy value,network load rate and user access cost of the candidate network are input into the second-level fuzzy logic system.At the same time,the output decision value is obtained by combining the adaptive rule matching,so as to select the best access network.Finally,the experimental results show that the algorithm can guarantee the network performance while reducing the time cost of the system.