Indoor VLC And WiFi Heterogeneous Network Handover Algorithm Research

Visible Light Communication(VLC)is a very promising way of indoor communication networking due to the advantages of wide spectrum,fast transmission rate,environment protection,and can combine lighting and communication.However,the direct-radiation characteristic of VLC makes it unable to meet the needs of user’s demand for uninterrupted mobile communication,meanwhile radio frequency(RF)network can achieve non-visual communication,the organic combination of the two will become the main hot research direction of the indoor high-speed communication network.For the optoelectronic heterogeneous network composed of VLC and RF,network handover method is a key scientific problem that must be solved,but only considering the vertical handover of the network cannot cope with the complex reality and provide higher quality of service.Therefore,this paper conducts research on the handover algorithm of indoor visible heterogeneous networks,incorporates horizontal handover with vertical handover,and solves the coordination problem of vertical and horizontal handover,the job is as follows.Firstly,we summarize the research background and development status of VLC and Wi Fi network,briefly explain the relevant principles of VLC/RF and existing algorithms,and point out the main problems in analyzing the current heterogeneous network algorithms.Then,in order to be able to accurately judge the switching timing of vertical handover and horizontal handover under the single-user motion scenario,the horizontal vertical handover algorithm(HVHO)based on dwell time is proposed,which combines vertical handover and horizontal handover through network dwell time,then we compare it with handover delay and the threshold time obtained from throughput calculation.Simulation results show that the proposed HVHO algorithm has higher average throughput and significantly lower average handover failure probability and average number of handovers compared to the traditional immediate vertical handover(IVHO)and dwell vertical handover(DVHO)algorithms.Finally,in the complex multi-user scenario,the Coordinated Horizontal and Vertical Handover(CHVHO)algorithm based on the Quality of Experience(Qo E)is proposed to address the problem of excessive complexity due to too many considerations.The algorithm introduces web servers for the purpose of storing network state information and reducing the time used to calculate and compare Qo E values.The traditional motion model is simplified by reducing the four influencing factors to two influencing factors,network staying time and received signal strength,which are taken into account in the algorithm.Different handovers are executed according to different scenarios.The simulation results show that although the Qo E-based CHVHO scheme considers more factors,the average Qo E,the average number of handover and the average handover failure probability are significantly improved.