Inter-eNodeB Handover on the X2 Interface
1.A UE sends a measurement report to
the eNodeB
to trigger the eNodeB
to initiate a handover.
2.The source eNodeB
sends a handover request to the target eNodeB.
3.After receiving this message, the
target eNodeB
checks whether the UE handover conditions are met. If the conditions are met,
the target eNodeB
sends a Handover Request Acknowledge message to the source eNodeB
to indicate that the handover preparation is ready.
4.The source eNodeB
sends the Handover Request Acknowledge message to the UE.
5.The source eNodeB
starts the transferring procedure by sending the SN Status Transfer message if
E-RABs are to be transferred.
6.Based on the RRC Connection
Reconfiguration message containing the MobilityControlInfo
IE, the UE changes radio parameter values and hands over to the target eNodeB.
7.After accessing the target eNodeB,
the UE sends the RRC Connection Reconfiguration Complete message to the target eNodeB.
8.Upon receiving the RRC Connection
Reconfiguration Complete message, the target eNodeB
sends the Path Switch Request message requesting the EPC to change the
user-plane path.
9.The EPC sends a Path Switch Request
Acknowledge message to the target eNodeB
if the EPC allows the user-plane handover.
10.Upon receiving the Path Switch
Request Acknowledge message, the target eNodeB
send the UE Context Release message to the UE, requesting the source eNodeB
to release the UE. This indicates the handover is successful. After receiving
the UE Conext
Release Command message, the source eNodeB
waits until local data transmission is complete and then releases the UE.
Inter-eNodeB X2 Handover Instance
Signaling tracing over the Uu interface on the UE side
Signaling tracing over the Uu interface on the source eNodeB side
Signaling tracing over the X2 interface on the source eNodeB side,
Signaling tracing over the Uu interface on the target eNodeB side
Signaling tracing over the S1 interface on the target eNodeB side
From group: eLTE Industry Wireless Network
