How does the 5G Core network handle mobility management and handover between different network slices?

The 5G Core network is designed to handle mobility management and handover between different network slices efficiently. To understand this process, let's break it down into key technical components and procedures:

1. Network Slicing:
   • Network slicing is a fundamental concept in 5G that allows the creation of multiple logical networks, called slices, on a shared physical infrastructure.
   • Each network slice is tailored to meet specific requirements (e.g., latency, bandwidth) for diverse use cases, such as enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low-latency communications (URLLC).
2. User Plane Function (UPF):
   • The UPF is a crucial element in the 5G architecture responsible for handling the user data and performing data plane functions.
   • In the context of mobility management and handover, the UPF plays a role in routing data between the User Equipment (UE) and the applications or services in the network slice.
3. Session Management:
   • The 5G Core uses a session management procedure to establish and maintain communication sessions between the UE and the network.
   • The Session Management Function (SMF) is responsible for controlling and managing sessions. It handles the mobility-related signaling and keeps track of the user's context during handovers.
4. Mobility Management:
   • Mobility management in 5G involves tracking the UE's movements and ensuring seamless connectivity as the UE moves across different locations and network slices.
   • The Mobility Management Function (AMF) handles mobility-related procedures, such as registration, context updates, and tracking area updates, to keep track of the UE's location and state.
5. Handover Process:
   • Handovers are necessary when a UE moves from one location to another or switches between different network slices. 5G supports various handover scenarios, including intra-slice handovers and inter-slice handovers.
   • During a handover, the AMF initiates a handover procedure, coordinating with the target AMF and UPF in the new network slice.
   • The SMF ensures the continuity of user sessions during handovers, updating the user context and ensuring that data continues to flow seamlessly.
6. Dual Connectivity and Multi-Connectivity:
   • 5G introduces the concepts of dual connectivity and multi-connectivity, allowing a UE to connect to multiple cells or network slices simultaneously.
   • This enables improved data rates, reliability, and efficiency, especially during handovers, as the UE can maintain connections with multiple nodes simultaneously.
7. Reconfiguration and Context Transfer:
   • As part of the handover process, the network elements involved need to reconfigure themselves to support the UE in the new location or network slice.
   • Context transfer mechanisms ensure that the user's context, including authentication and session information, is seamlessly transferred from the source to the target AMF and UPF.