Section: 10.16.3 Inter-system handover from 5GS to EPS with the Source Node used as target Secondary Node
Content: Inter-system handover from 5GS to EPS with the Source Node used as target Secondary Node refers to a deployment scenario where the source gNB and the target en-gNB are realised within the same network entity. Figure 10.16.3-1: Inter-system handover from 5GS to EPS with the Source Node used as target Secondary Node 1. The (source) gNB triggers handover preparation phase including in the Source eNB to Target eNB Transparent Container the Source NG-RAN node ID and the RAN UE NGAP ID. 2. The target eNB receives the Source NG-RAN node ID and the RAN UE NGAP ID in the Source eNB to Target eNB Transparent Container. 3.-4. The X2AP SgNB Addition procedure is performed towards the (target) en-gNB indicated in the Source NG-RAN node ID received in step 2. The eNB includes the RAN UE NGAP ID received in step 2 in the X2 SgNB Addition Request message. 5.-8. Handover proceeds. 9. DL UP data is forwarded in a node-internal way for the SN terminated bearers.