二零二三年 优质公开课signalingflowofLTE.pptx

Signaling Flow of LTEMobile Communication TechnologyLecturer：Wenmao Luoetwork architectureProtocol stack structureWorking mode and state of UEUE identificationCONTENT 01Network architecturePART ONE Network architectureLTE network architecture Network architectureThe whole TD-LTE system consists of three parts：Core network （EPC, Evolved Packet Core ）Access network （eNodeB）User equipment （UE）EPC is divided into three parts：MME (Mobility Management Entity, Responsible for signaling processing part ）S-GW (Serving Gateway , Responsible for local network user data processing ）P-GW (PDN Gateway， Responsible for processing user packets and other network  processing)Access network (also known as E-UTRAN) is composed of eNodeBnetwork interfaceS1 Interface ：eNodeB and EPCX2 Interface ： between eNodeB Uu Interface ：eNodeB and UELTE Network Entity Network architectureFunctions of eNB ：Wireless resource management related functions, including wireless bearer control, admission control, connection mobility management, uplink / downlink dynamic resource allocation / scheduling, etc;IP header compression and user data stream encryption;Mme selection when UE is attached;Provide routing of user interface data to S-GW;Paging message scheduling and transmission;Scheduling and transmission of system broadcast information;Measurement and measurement report configuration.Functions of MME：Paging message distribution, Mme is responsible for distributing paging messages to relevant ENB according to certain principles;Safety control;Mobility management in idle state;EPC load control;Encryption and integrity protection of non access layer signaling.Functions of network element Network architectureFunctions of S-GW：Terminate the user plane data packets generated due to paging;Support user plane handoff due to UE mobility.Functions of P-GW：Filtering and checking of per user packets;User IP assignment.Functions of network element 02Protoco