Research On Key Technology Of 4G Mobile Communication Experiment System Based On NFV

4G mobile communication system includes radio access network and all-IP packet core network EPC(Evolved Packet Core).With the continuous evolution of the core network,the 4G network only defines the packet domain of the all-IP structure and no longer includes the circuit domain.The circuit domain-based voice and SMS services in 2G and 3G will be based on IMS(IP Multimedia Subsystem)in 4G.There is a big difference between the group architecture bearer and the communication process and protocol.Although 3GPP(the 3rd Generation Partnership Project)has established a standard specification for mobile communication networks,because the core network of operator is relatively closed and there are differences in the network deployment and communication business processes,it is impossible to directly carry out technical research,communication service testing,and customized communication services.Therefore,it is necessary to carry out technical research by building experimental systems.This article builds a 4G mobile communication experimental system architecture based on Network Functions Virtualization(NFV)technology,and decouples the main communication network element functions such as wireless access network,core network and IMS core network,and deploys them on x86 general-purpose servers separately to implement Vo LTE(Voice over LTE)voice/video calls,SMS based on IMS,4G internet access services and so on.At the same time,relying on the system to study 4G mobile communications and international roaming interworking network technologies,the potential security issues are analyzed.This article also designs and implements the 4G network protocol monitoring and analysis function based on scalable DPI technology for signaling monitoring and signaling process troubleshooting.The main research contents and innovations of this article are as follows:1.This article studied the mobile core network architecture,network element functions,protocol components and the main signaling process.This article also analyzed the 4G core network architecture and main communication network element functions,roaming interworking network architecture,the user plane and control plane main protocols of core network and signaling procedures such as user attachment,service request,paging,handover and bearer establishment through 3GPP standard specifications.2.This article studied the IMS network architecture,network element functions and VoLET session processes.This article also analyzed the IMS core network composition,call session control network element functions,VoLTE core control protocol,and the end-to-end basic session processes and scenarios including VoLTE registration,call and logout.3.This article implemented to design and construct 4G mobile communication system based on network functions virtualization technology.Through the NFV technology,the traditional centralized 4G core architecture is converted into a distributed architecture,and virtualization technology is used to virtualize the 4G network element functions,and the main network elements of the EPC core network and the IMS core network are decoupled based on the decoupling of the network element equipment hardware and software.These network elements are decoupled so that they are deployed on a separate server or a virtual machine.This experiment used two sets of experimental systems to achieve roaming and interworking between operators through the construction of 4G experiment system,on which users can access the internet,apply Vo LTE voice and video,SMS and other communication services.4.This article designed and implemented a 4G network protocol monitoring and analysis system based on a scalable Deep Packet Inspection(DPI)technology.A protocol filtering module is constructed by the expandable DPI technology in order to filter out the control plane protocol,user plane protocol and Diameter protocol.The detection process is optimized through a combination of many kinds of detection techniques and data stream information detection result caching technology.According to the results of the protocol filtering module,the corresponding protocol analysis module is invoked to complete the data parsing,and the results of parsing data are restored and presented in accordance with the signaling communication flow,in order to implement signaling monitoring and troubleshooting functions.