二零二三年 优质公开课SignalingFlowof5G.pptx

Signaling Flow of 5GMobile Communication TechnologyLecturer：Gu Yanhua What is SignlingSignaling is a messaging mechanism.?gNodeBgNodeBgNodeB 010203Access Process of 5GMobility Management Process of 5GRelease Process of 5GCONTENT 01Access Process of 5GPART ONE Access Process of 5GTerminals in SA network directly complete initial access in 5G.UE searches SSB, completes downlink synchronization, obtains PCI,demodulate MIB message, and completes downlink frame synchronization.Obtain RMSIaccording to the parameters in the MIB message to complete the downlink cell resident.Initiate random access process in the current cell to complete uplink synchronization.?UE enters the initial access process after random access. Access Process of 5G(1) UE sends the RM-NAS registration request to the new AMF.(2)The new AMF sends the context information of UEContextTransfer request UE to the old AMF, and the old AMF sends the corresponding information to the new AMF.?(3) As an optional process, the new AMF sends an identity request message to the UE.?(4) UE authentication initiated by new AMF.?(5) The new AMF notifies the old AMF that UE has completed registration.?(6) The new AMF initiates a request to query the validity of IMEI.?(7) The terminal replies to IMEI. Access Process of 5G(8) Establish UE context in the new AMF. (9) The new AMF initiates PCF communication to obtain the user billing policy. (10) PCF requests UE event subscription. (11) Activate the user plane connection of the PDU session. (12) New AMF notifies UE that the registration request has been received. (13) UE confirms the completion of registration. 02Mobility Management Process of 5GPART TWO Mobility Management Process of 5GMobility management process refers to the process of UE switching in the connected state. Switching refers to the process of UE moving between different cells in the connected state to complete the update of UE context. The mobility management process in the NSA network c