XnAP Messages

XnAP carries signaling between gNB nodes over Xn for mobility and coordination.

Browse future inter-gNB signaling references related to handover, status transfer, and coordination.

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This is the full published list for the XnAP category. Use the filter section above for a narrower interactive view.

XnAP 5G

5G XnAP - Handover Request

Handover Request is the XnAP message the source NG-RAN node sends to the target NG-RAN node to request preparation of resources for an incoming handover on the Xn interface.

Source NG-RAN node -> Target NG-RAN node 3GPP TS 38.423
XnAP 5G

5G XnAP - Handover Request Acknowledge

Handover Request Acknowledge is the XnAP message the target NG-RAN node sends to the source NG-RAN node to report the prepared resources at the target and confirm that the handover branch is ready to continue.

Target NG-RAN node -> Source NG-RAN node successfulOutcome 3GPP TS 38.423
XnAP 5G

5G XnAP - SN Status Transfer

SN Status Transfer is the XnAP message the source NG-RAN node sends to the target NG-RAN node to transfer PDCP sequence-number and HFN status, and related mobility information, so the target can continue bearer handling without duplicate or out-of-order treatment errors.

Source NG-RAN node -> Target NG-RAN node 3GPP TS 38.423
XnAP 5G

5G XnAP - UE Context Release

UE Context Release is the XnAP message used to indicate that radio and control-plane resources for the associated UE context may be released at the other node after handover success, dual-connectivity release, or UE context retrieval completion.

Target NG-RAN node -> Source NG-RAN node; also M-NG-RAN node -> S-NG-RAN node in DC branches 3GPP TS 38.423
XnAP 5G

5G XnAP - Xn Setup Request

Xn Setup Request is the first XnAP interface-management message an NG-RAN node sends after the Xn-C transport association becomes operational so the peer node can learn the initiating node identity, served-cell inventory, and grouping information before normal inter-node signaling starts.

Initiating NG-RAN node -> Peer NG-RAN node; outcomes: peer -> initiator 3GPP TS 38.423
XnAP 5G

5G XnAP - Xn Setup Response

Xn Setup Response is the successful XnAP outcome the receiving NG-RAN node returns after accepting Xn Setup Request, making the Xn relationship operational and optionally returning the peer-side served-cell and grouping view the initiator should store for later inter-node procedures.

Peer NG-RAN node -> Initiating NG-RAN node successfulOutcome 3GPP TS 38.423

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