Sign in Subscribe

UL Handover Preparation Transfer Complete

Last updated on 

The "UL Handover Preparation Transfer Complete" is a technical procedure in mobile communication networks, such as LTE (Long-Term Evolution) and 5G, that signifies the successful completion of the preparation phase for an uplink (UL) handover. An uplink handover is the process of transferring the UL communication from the source cell to the target cell to ensure seamless connectivity while a User Equipment (UE) moves within the network. Here's a detailed technical explanation of the "UL Handover Preparation Transfer Complete" procedure:

1. Handover Trigger and Preparation:

  • The UL Handover Preparation Transfer Complete procedure is part of the overall handover process, which is triggered by various events, such as the UE's mobility or network optimization needs.
  • Prior to the handover, the network initiates preparations, which include selecting a target cell and allocating resources in the target cell for the UE's uplink transmission.

2. UE Handover Preparation:

  • The UE also prepares for the handover. It tunes its UL transmission parameters to align with the target cell's frequency and timing.
  • The UE may also perform measurements on neighboring cells to determine the best target cell for the handover.

3. Handover Request and Configuration:

  • Once preparations are complete, the network generates an "UL Handover Preparation Transfer Request" message to instruct the UE to begin the handover process.
  • This message includes information about the target cell, timing, and UL configuration details.

4. Transmission to the UE:

  • The "UL Handover Preparation Transfer Request" message is transmitted from the network to the UE over the source cell's downlink channel.
  • The UE receives the message and processes the instructions.

5. UE Acknowledgment:

  • Upon successfully receiving and processing the "UL Handover Preparation Transfer Request" message, the UE acknowledges it by sending an acknowledgment message back to the network.
  • This acknowledgment confirms the UE's readiness to proceed with the handover.

6. Network Verification:

  • The network verifies the acknowledgment from the UE to ensure that the UE is prepared and ready for the handover.

7. UL Handover Preparation Transfer Complete:

  • Once the network has verified the UE's acknowledgment and is satisfied that the preparations are complete, it sends an "UL Handover Preparation Transfer Complete" message to the UE.
  • This message signifies that the handover preparation phase has been successfully completed.

8. Handover Execution:

  • Following the "UL Handover Preparation Transfer Complete" message, the actual handover execution phase begins.
  • The UE switches its UL transmission to the target cell, and the network ensures that the resources are allocated and synchronized for the UE's UL communication in the target cell.

9. Procedure Completion:

  • The "UL Handover Preparation Transfer Complete" procedure is considered complete when the UE has successfully transitioned its UL communication to the target cell, and the network resources are ready for the UE's UL transmission.
  • This sets the stage for the seamless continuation of the UL communication in the new cell.

The "UL Handover Preparation Transfer Complete" procedure is a critical step in ensuring a smooth handover process for uplink transmissions. It verifies that both the UE and the network are ready for the handover, reducing the chances of communication interruption during the transition.