Performance Research And Evalution Of Heterogeneous Network Handover Algorithm In Emergency Scenario

Building an efficient and smooth emergency communication network in case of various natural disasters and emergencies is very important to ensure the safety of people’s lives and property.However,at present,a variety of communication systems in the emergency communication network mostly adopt the form of independent deployment,strong heterogeneity and lack of effective vertical handover means,which makes it difficult for disaster and rescue personnel to access the best communication system in time according to different emergency communication needs.Therefore,this paper designs and builds a system level simulation platform to study and evaluate the performance of heterogeneous network vertical handover algorithm under different disaster conditions and different emergency communication services.The main work contents and innovations include:Firstly,according to relevant protocols and standards,this paper designs and builds a heterogeneous network system level simulation platform for emergency scenarios.In the platform,a variety of communication sub networks including ultrashort wave communication,LTE communication,5g communication,tethered UAV Communication,fixed wing UAV Communication and other communication systems are built,as well as emergency business models including emergency voice communication,emergency video communication and emergency video data buffer stream transmission.The platform realizes the functions of propagation model,antenna model and adaptive coding modulation of different communication systems,and calibrates with the results in the standard to verify the correctness of the platform.Then,based on the system level simulation platform,the performance of heterogeneous network vertical handover algorithms based on received signal strength,signal to interference noise ratio,simple weighting method and Q-learning in different emergency scenarios are simulated.The simulation results show that in the emergency scenario with a base station damage probability of 20%,using the vertical handover algorithm based on Q-Learning can make the emergency communication network have better performance.In the emergency scenario where the damage probability of the base station is 50%or 80%,the vertical handover algorithm based on saw can make the emergency communication network have better performance.In the emergency scenario where the emergency video data buffer streaming service accounts for 80%,the use of SINR based vertical handover algorithm can make the emergency communication network have better performance.In the emergency scenario with user priority,when the damage probability of the base station is 20%or 50%,using the vertical handover algorithm based on Q-Learning can make the emergency communication network have better performance.When the base station damage probability is 80%,the use of SAW based vertical handover algorithm can make the emergency communication network have better performance.Finally,by comprehensively analyzing the advantages and disadvantages of the current vertical handover algorithms,this paper proposes a heterogeneous network vertical handover algorithm based on migration-Q learning,and verifies the performance of the proposed algorithm based on the system level simulation platform.Simulation results show that the algorithm has fast convergence speed,is suitable for all emergency scenarios,can effectively improve the network performance in emergency scenarios,and has certain practical value.Compared with the Q-learning algorithm with the best performance among the existing algorithms,the proposed algorithm can reduce the simulation time loss by 50.3%and improve user satisfaction by at least 1.4%in all scenarios.By building a heterogeneous network system level simulation platform for emergency scenarios,this paper simulates and evaluates the performance of common vertical handover algorithms in different emergency scenarios,and proposes a heterogeneous network vertical handover algorithm based on migration-Q learning.The algorithm is suitable for emergency scenarios with different structures and has fast convergence speed.At the same time,it can effectively improve the performance of the network in emergency scenarios,which provides a reference for the setting and application of vertical handover algorithm in emergency scenarios.