5g handover call flow

The handover process in a 5G network involves transferring a user's ongoing communication session from one cell to another seamlessly. This can happen for various reasons, such as improving network efficiency, load balancing, or ensuring continuous connectivity as the user moves through the network. The handover call flow in a 5G network can be complex, but I'll provide a simplified overview:

1. Triggering the Handover:
   • Handover can be triggered based on various factors, such as signal strength, load balancing, or user mobility.
   • The decision to handover is made by the network's mobility management functions.
2. Measurement and Report:
   • The user equipment (UE) continuously measures the signal strength and other parameters of neighboring cells.
   • When certain conditions are met, the UE reports its measurements to the serving cell.
3. Handover Decision:
   • The serving cell evaluates the reported measurements and decides whether a handover is necessary.
   • If a handover is deemed necessary, the network determines the target cell for handover.
4. Resource Allocation in Target Cell:
   • The target cell prepares resources for the incoming handover, ensuring that it can accommodate the UE seamlessly.
5. Handover Command:
   • The serving cell sends a handover command to the UE, instructing it to prepare for handover to the target cell.
6. UE Preparation:
   • The UE prepares for handover by adjusting its transmission parameters and allocating resources for the target cell.
7. Data Forwarding:
   • The serving cell starts forwarding the user's data to the target cell, ensuring continuity of the communication session.
8. Handover Execution:
   • The UE physically switches its connection from the serving cell to the target cell.
9. Handover Completion:
   • The target cell acknowledges the successful handover to the serving cell.
10. Data Forwarding in Target Cell:
    • The target cell takes over the communication session, and data continues to be forwarded to and from the UE.

Throughout this process, various signaling messages are exchanged between the UE and the network elements to coordinate the handover. The specific procedures and messages involved can vary depending on the type of handover (e.g., inter-frequency handover, intra-frequency handover) and the network architecture. Additionally, 5G networks may involve both mobility between cells within the same Radio Access Network (RAN) and handovers between different types of RANs (e.g., 5G to LTE).