Design And Implementation Of Location Management Method In Integrated Terrestrial-Satellite Network

With the rapid growth of mobile data traffic and the number of terminal equipment,the limitation of coverage and network capacity in terrestrial network is becoming more and more obvious.Satellite network with large communication capacity,wide coverage and high flexibility can make up for the deficiency of terrestrial network.Therefore,the integrated terrestrial-satellite network based on terrestrial network and expanded by satellite network is an important development trend of future network.In location management,due to the high-speed movement of LEO satellite nodes,the topological structure of the integrated terrestrial-satellite network is complex and highly variable,and the access satellites of terminals are constantly changing,which leads to frequent location updates,high signaling overhead,high location query complexity and low efficiency.This paper proposes a hierarchical location management method based on identity separation according to the highly variable topology of the integrated terrestrial-satellite network.Based on the separation of identity identification and location identification,this method tracks the location of users in the network through dynamic location identification and takes the mapping relationship between identity and location identification as the basis of location management,which improves the performance of location management and the support of mobility.Firstly,a hierarchical location update method is designed for location update,which can be divided into intra domain update and inter domain update.The intra domain update only needs to update the intra domain relationship and requires less signaling.By reducing the number of inter domain updates,the signaling overhead in location management is reduced.Then,in location query,a location query method based on consistency verification is designed.The user caches the location information of the correspondent node during communication.When the user initiates communication again,the user queries the cache first and tests the location information found in the cache through the consistency verification process.After confirmation,the user communicates directly,reducing the query steps.In the process of location query,by caching and testing the location information,the query complexity is reduced and the query efficiency is improved.Finally,simulation experiments are carried out.Through comparative analysis,it is proved that the proposed method can effectively reduce the cost of location update and improve the efficiency of location query.This paper designs and develops the location management system of integrated terrestrial-satellite network to further verify the performance of the proposed method.Firstly,the function of the system is clarified through demand analysis.Then the system design is introduced in detail from four modules:user management,LEO satellite management,domain mapping server management and visualization.Finally,each functional module of the system is tested,and the system interface and satellite constellation operation track are displayed.By simulating the location management process,the proposed method is compared and analyzed,which further verifies that it has better performance in location update cost and location query.