Control Plane

CP Control Plane

5G Control Plane is responsible for decision-making and signalling. It functions alongside the User Plane (which transmits the data itself). The UE uses the control plane to register, setup and manage sessions, and securely communicate with the network. Those actions are driven by the 5G core network functions: the AMF handles access and mobility signalling, the SMF manages session establishment/modification, the UDM supports subscription data and related identity/accounting data, and the NSSF is involved when network slicing needs to be selected for the UE/service.

On the signaling side, control-plane messages can be separated into layers/components. Most importantly, the NAS procedures. NAS is where you’ll see the key mobility and session-related management signaling between the UE and the core, while other control-plane protocols (like NGAP for the 5G RAN and core side communication) support how those NAS messages get transported through the access network.

🔗 https://www.sharetechnote.com/html/5G/5G_Core_AMF.html
🔗 https://www.sharetechnote.com/html/5G/5G_CallProcess_InitialAttach.html