Xn Handover Call Flow
This section describes Xn Handover call flow.

Step |
Description |
---|---|
1 |
Once signaling that involves the UE, source and destination gNB have taken the decision to handover, the destination gNB constructs a PATH SWITCH REQUEST with the list of PDU sessions that have successfully switched and the list of PDU sessions that were not successful. |
2 |
For each of the PDU Sessions, the AMF constructs a SmContext Modify request and sends it to the corresponding SMF to update the tunnel endpoint ID for the gNB. |
3 |
The SMF responds with either 200 OK or an appropriate cause code. |
4 |
The AMF creates a PATH SWITCH REQUEST ACKNOWLEDGEMENT including PDU sessions that are successful in a success list and the PDU sessions that have failed in a failure list and sends them to the destination gNB. The AMF clears the source gNB context and attaches the destination gNB context to the UE context. |