5G • RAN
XnAP
Xn Application Protocol
Signaling protocol operating over Xn-C standardizing procedural messages between peer gNodeBs.
Technical Explanation
Specified in 3GPP TS 38.423, XnAP defines elementary procedures between gNodeBs: Handover Request / Request Acknowledge, S-Node Addition / Modification (Dual Connectivity), Retrieve UE Context (for RRC_INACTIVE resume), RAN Paging, Resource Status Reporting, and Secondary RAT Data Usage Reporting.
Key Functions
- Standardizes signaling messages between neighboring gNodeBs
- Executes Handover Preparation, Cancellation, and SN Addition procedures
- Transfers dormant UE context records during RRC resume
Specifications
3GPP TS 38.423
Interfaces
XnXn-C
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