TS 38.423 – NG-RAN Xn Application Protocol
3GPP TS 38.423 is the 3GPP Technical Specification for NG-RAN Xn Application Protocol. Its official 3GPP title is “Xn application protocol (XnAP)”. It is published in 5 releases (Rel-15 to Rel-19); the latest version is 19.4.0 in Rel-19.
Defines XnAP control-plane signaling procedures between NG-RAN nodes, supporting mobility, resource coordination, dual connectivity, and other inter-node functions.
Releases and versions of TS 38.423
| Release | Latest version | Links |
|---|---|---|
| Rel-19 | 19.4.0 | Read · Download (3GPP) |
| Rel-18 | 18.9.0 | Read · Download (3GPP) |
| Rel-17 | 17.14.0 | Read · Download (3GPP) |
| Rel-16 | 16.20.0 | Read · Download (3GPP) |
| Rel-15 | 15.20.0 | Read · Download (3GPP) |
Scope of TS 38.423
Category: Radio Access (Xn Application Protocol). Technology generation: 5G. Network layer: RAN.
Who should read this specification?
- Network operators
- Device manufacturers
- Researchers and academics
Implementation notes
Complexity level: Expert. Implementation difficulty: High.
Key technologies
Excerpt from TS 38.423
1 Scope
The present document specifies the radio network layer signalling procedures of the control plane between NG-RAN nodes in NG-RAN. XnAP supports the functions of the Xn interface by signalling procedures defined in this document. XnAP is developed in accordance to the general principles stated in TS 38.401 [2] and TS 38.420 [3].
Excerpt from the official 3GPP document (Rel-19). Read the full specification with interactive table of contents.
Specifications referenced by TS 38.423
- TS 38.331 NR Radio Resource Control (RRC)
- TS 38.323 PDCP Protocol Specification
- TS 36.300 E-UTRAN Radio Interface Protocol Architecture
- TS 23.502 5G System Procedures
- TS 36.331 E-UTRA Radio Resource Control (RRC) Protocol
- TS 29.281 GTPv1-U Protocol Specification
- TS 38.424 Xn Interface User Plane Transport Protocol
- TR 21.905 3GPP Terminology and Definitions
- TS 38.414 NG Interface User Plane Protocol
- TS 38.412 NG Signalling Transport
- TS 23.003 Numbering, Addressing and Identification
- TS 32.422 Trace, MDT and UE Measurement Control
Specifications that reference TS 38.423
- TS 23.501 5G System Architecture
- TS 23.502 5G System Procedures
- TS 38.300 NR and NG-RAN Overall Description
- TS 36.300 E-UTRAN Radio Interface Protocol Architecture
- TS 38.331 NR Radio Resource Control (RRC)
- TS 38.413 NG Application Protocol (NGAP) Specification
- TS 28.541 5G Network Resource Model (NRM) Stage 2 and 3
- TS 28.552 5G Network Performance Measurements
- TS 23.216 SRVCC Architecture Enhancements
- TS 23.247 5G Multicast and Broadcast Services
- TS 23.287 5G V2X Architecture Enhancements
- TS 37.340 Overview of Multi-Connectivity Operation using E-UTRA and NR
Other specifications in the 38 series
- TS 38.415 PDU Session User Plane Protocol
- TS 38.420 Introduction to Xn interface specifications
- TS 38.421 Xn Interface Layer 1 Specification
- TS 38.422 Xn Signalling Transport Specification
- TS 38.424 Xn Interface User Plane Transport Protocol
- TS 38.425 NR User Plane Protocol Specification
- TS 38.455 NR Positioning Protocol A
- TS 38.460 E1 Interface General Aspects and Principles
Frequently asked questions
What is 3GPP TS 38.423?
3GPP TS 38.423 is the 3GPP Technical Specification for NG-RAN Xn Application Protocol. Defines XnAP control-plane signaling procedures between NG-RAN nodes, supporting mobility, resource coordination, dual connectivity, and other inter-node functions.
Which 3GPP releases include TS 38.423?
TS 38.423 is published in 5 releases, from Rel-15 to Rel-19. The latest version on 3GPP Explorer is 19.4.0 (Rel-19).
What category does TS 38.423 belong to?
TS 38.423 belongs to the Radio Access (Xn Application Protocol) category of 3GPP specifications. It applies to 5G networks.
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