Which 5G core network function manages registration and mobility?
The 5G core network function that manages registration and mobility is known as the “Access and Mobility Management Function” (AMF). This function is responsible for handling the registration of user equipment (UE) in the network, tracking their mobility as they move between different cells or access points, and ensuring seamless handovers during mobility events.
How the 5G core network manages registration and mobility:
1. Registration Process:
- UE Registration: When a User Equipment (UE) wants to connect to the 5G network, it initiates the registration process. The UE sends a registration request to the Access and Mobility Management Function (AMF) in the core network.
- AMF Verification: The AMF verifies the UE’s identity, its subscription status, and authentication credentials to ensure it’s allowed on the network.
- Assignment of Temporary Identity: If the UE is allowed, the AMF assigns a temporary identity (SUPI or SUCI) to the UE, which is used for subsequent communication.
2. Mobility Management:
- Tracking UE Location: Once registered, the AMF continuously tracks the UE’s location as it moves within the coverage area of the 5G network.
- Mobility Events: When the UE moves between different cells or access points, it triggers mobility events. These events include handovers, which are managed by the AMF.
- Handover Management: The AMF plays a crucial role in handovers, ensuring that the UE’s session is seamlessly transferred to a new cell or access point without service interruption.
3. Session Continuity:
- Session Management: During mobility events, the AMF coordinates with other network functions to maintain the continuity of the UE’s ongoing communication sessions, such as voice calls or data transfers.
- Quality of Service (QoS): The AMF ensures that the QoS requirements of the UE are maintained as it moves, optimizing parameters like latency and bandwidth.
4. Security and Authentication:
- Authentication: The AMF is responsible for initiating and managing the authentication and key agreement (AKA) process to secure the communication between the UE and the network.
- Security Context: It maintains a security context for each UE, which includes encryption keys and authentication tokens to ensure the confidentiality and integrity of data.
5. Context Transfer:
- Interworking with Other Functions: In cases where the UE moves between different 5G networks or interacts with legacy networks (4G, 3G), the AMF facilitates the transfer of relevant context information to ensure a smooth transition.
In summary, the Access and Mobility Management Function (AMF) in the 5G core network is responsible for handling UE registration, tracking UE mobility, managing handovers, ensuring session continuity, maintaining security, and facilitating context transfer. It plays a central role in providing a seamless and secure mobile communication experience for users in 5G networks.