Design And Simulation Of Satellite-terrestrial Integrated Core Network Based On 5G

In order to cope with the rapid growth of traffic caused by various emerging business applications,and to meet the needs of users in the fields of public security,emergency and military,Satellite-Terrestrial Integrated Network have become a hot spot for domestic and foreign researchers.With the depth of related research,there are two problems that bring serious challenges to the improvement of the performance of the Satellite-Terrestrial Integrated Network: First,the existing network architecture lacks the ability to control user access on the satellite,which brings increased data processing response delay and packet loss;second,the current satellite networking mechanism cannot effectively guarantee the response delay of satellite networking and the flexibility of network expansion.To address the above problems,this thsis designs a satellite-terrestrial integrated core network architecture in combination with 5G core network technology,and proposes a dynamic deployment scheme for satellite control nodes to achieve flexible expansion of satellite networks while ensuring the response delay of satellite networking.The main work of this thsis is as follows:1.To address the problem that the existing Satellite-Terrestrial Integrated Network architecture lacks on-board access control capability and is limited by satellite resources,a5G-based satellite-terrestrial integrated core network architecture is designed.The core network functions are designed to be lightweight and relocated to the satellite to realize the sinking of the core network functions to the data edge,and to design the terminal lightweight access signaling and process to reduce the user access processing delay for the frequent access problems caused by the high-speed movement of satellite nodes.The satellite networking control function is added to the ground core network to manage satellite networking,task offloading and data caching to realize integrated control of the satelliteterrestrial network.2.To address the problems of high response delay and low flexibility of satellite network,we design a delay-based dynamic deployment scheme for satellite control nodes.Firstly,divide the satellite mobile core subnet area according to the mobile task coverage requirements,then analyze the delay of the network control surface in the satellite mobile core subnet,establish a delay-optimized satellite control node deployment model,and optimize the node deployment with the goal of minimizing the delay;Then design an approximation algorithm to solve the model to obtain the results of satellite network control node deployment.Then,we design an approximation algorithm to solve the model to obtain the results of satellite network control node deployment;finally,we verify through simulation that the solution can improve the flexibility of the network while ensuring the response delay of the satellite network.3.Based on the EXata simulation platform,we build an experimental scenario to verify that the design of this thsis can reduce 38% of the user access processing delay and 55% of the average network packet loss rate compared with the standard satellite-terrestrial integrated network solution.