Research On Access Selection For Terrestrial-Satellite Networks Oriented To Multi-Service Of Power Grid

With the construction and development of the power grid,the transmission lines have covered the entire region.In order to achieve real-time and reliable monitoring of the transmission lines,to solve the problems of untimely manual monitoring and high maintenance costs,the application of automatic transmission line monitoring technology is inevitable for the future power grid trend.However,in remote areas with harsh natural environments,the construction cost of optical fiber networks is too high,and the coverage of wireless public networks is poor,and the bandwidth is very limited,which cannot meet the future transmission line monitoring requirements for highdefinition video,high-definition images,and large amounts of sensor data.In order to ensure the communication coverage and reliability of transmission line monitoring services in remote areas,the low-orbit satellite network and the 5G network are combined to form a terrestrial-satellite network to provide network connection for transmission line monitoring terminals,which can ensure the reliable execution of various services.In order to ensure the stability of the transmission line monitoring service,this thesis proposes a terrestrial-satellite network architecture for grid multi-service by analyzing the communication characteristics of the transmission line monitoring service.Under the terrestrial-satellite network architecture,the monitoring terminal does not directly transmit data with the satellite,the low-orbit satellite network is integrated with the 5G network by providing data backhaul for the low-orbit satellite small base stations.At the same time,the 5G network includes macro base stations and traditional ground small base stations.Base station,the monitoring terminal can access the terrestrial-satellite network through three different types of base stations.In the scenario of multiple monitoring terminals and multiple networks,how to perform access selection has become a key technology for network management.This article studies this issue,and the main work includes:1.Considering the different communication requirements of different transmission line monitoring services and the performance difference of different networks,in order to ensure the Qo S of services and the reliability of transmission line monitoring,an access selection algorithm based on service Qo S is proposed.According to the service requirements,the attribute factors that affect the terminal access options are determined,and design utility functions according to the characteristics of different attributes to replace the traditional range transformation method to normalize the attribute values of the network,construct a weight calculation model that combines subjective and objective,and use The analytic hierarchy process(AHP)calculates the subjective weight,uses the entropy weight method to calculate the objective weight,and finally,calculates the relative closeness of each network by the Technique for Order Preference by Similarity to an Ideal Solution(TOPSIS),and sorts the candidate networks to obtain the best candidate network for each monitoring terminal to access.Simulation results show that the algorithm can better meet the communication needs of different transmission line monitoring services,has a low service blocking rate,ensures reliable operation of the service,and can improve the utilization rate of network resources.2.In the terrestrial-satellite network,the performance difference between different networks is large.In order to ensure the balance between the user side and the network side and maximize the comprehensive income,an access selection algorithm based on user and network bilateral profit is proposed.The factors affecting the revenue of the user side and the network side are analyzed,and the user side utility function and the network side utility function are respectively defined to calculate the revenue of the user side and the network side after performing the corresponding access;then the matching parameters of the user side and the available load of network are used as matching restriction conditions,and matching windows of the user side and the network side are defined to improve the execution efficiency of the access selection algorithm service and network complete access selection through matching game in matching window,.Simulation results show that the access selection algorithm based on matching game can better meet the differentiated Qo S requirements of transmission monitoring services,to a certain extent,it ensures the load balancing of the terrestrial-satellite network,has a lower service blocking rate and a higher access selection efficiency.