Content for TS 38.423 Word version: 18.2.0
1 Scope p. 17
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 and TS 38.420.
2 References p. 17
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
- References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific.
- For a specific reference, subsequent revisions do not apply.
- For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
[1]
TR 21.905: "Vocabulary for 3GPP Specifications".
[2]
TS 38.401: "NG-RAN; Architecture Description".
[3]
TS 38.420: "NG-RAN; Xn General Aspects and Principles".
[4]
TS 38.422: "NG-RAN; Xn Signalling Transport".
[5]
TS 38.413: "NG-RAN; NG Application Protocol (NGAP) ".
[6]
TS 25.921: "Guidelines and principles for protocol description and error handling".
[7]
TS 23.501: "System Architecture for the 5G System".
[8]
TS 37.340: "Evolved Universal Terrestrial Radio Access (E-UTRA) and NR; Multi-connectivity; Stage 2".
[9]
TS 38.300: "NR; NR and NG-RAN Overall Description; Stage 2".
[10]
TS 38.331: "NR; Radio Resource Control (RRC) Protocol specification".
[11]
TS 38.323: "NR; Packet Data Convergence Protocol (PDCP) specification".
[12]
TS 36.300: "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2".
[13]
TS 23.502: "Procedures for the 5G System; Stage 2".
[14]
TS 36.331: "Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC) protocol specification".
[15]
ITU-T Recommendation X.691 (2002-07): "Information technology - ASN.1 encoding rules - Specification of Packed Encoding Rules (PER) ".
[16]
ITU-T Recommendation X.680 (2002-07): "Information technology - Abstract Syntax Notation One (ASN.1): Specification of basic notation".
[17]
ITU-T Recommendation X.681 (2002-07): "Information technology - Abstract Syntax Notation One (ASN.1): Information object specification".
[18]
TS 29.281: "General Packet Radio Service (GPRS); Tunnelling Protocol User Plane (GTPv1-U)".
[19]
TS 38.424: "NG-RAN; Xn data transport".
[20]
TS 38.414: "NG-RAN; NG data transport".
[21]
TS 38.412: "NG-RAN; NG Signalling Transport".
[22]
TS 23.003: "Numbering, Addressing and Identification".
[23]
TS 32.422: "Trace control and configuration management".
[24]
TS 38.104: "NR; Base Station (BS) radio transmission and reception".
[25]
TS 36.104: "Base Station (BS) radio transmission and reception ".
[26]
TS 36.211: "Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation".
[27]
TS 36.101: "User Equipment (UE) radio transmission and reception".
[28]
TS 33.501: "Security architecture and procedures for 5G System".
[29]
TS 33.401: "3GPP System Architecture Evolution (SAE); Security architecture".
[30]
TS 24.501: "Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3".
[31]
TS 36.413: "Evolved Universal Terrestrial Radio Access Network (E-UTRAN); S1 Application Protocol (S1AP)".
[32]
TS 25.413: "UTRAN Iu interface RANAP signalling".
[33]
TS 38.304: "NR; User Equipment (UE) procedures in Idle mode and RRC Inactive state".
[34]
TS 36.304: "Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) procedures in idle mode".
[35]
TS 38.321: "NR; Medium Access Control (MAC) protocol specification".
[36]
TS 36.321: "Evolved Universal Terrestrial Radio Access (E-UTRA); Medium Access Control (MAC) protocol specification".
[37]
RFC 5905: "Network Time Protocol Version 4: Protocol and Algorithms Specification".
[38]
TS 23.287: "Architecture enhancements for 5G System (5GS) to support Vehicle-to-Everything (V2X) services".
[39]
TS 38.211: "NR; Physical channels and modulation".
[40]
TS 38.213: "NR; Physical layer procedures for control".
[41]
TS 38.473: "NG-RAN; F1 application protocol (F1AP)".
[42]
TS 38.314: "NR; Layer 2 measurements".
[43]
TS 37.320: "Radio measurement collection for Minimization of Drive Tests (MDT)"
[44]
TS 36.423: "Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 application protocol (X2AP)".
[45]
TS 29.244: "Interface between the Control Plane and the User Plane Nodes; Stage 3".
[46]
TS 23.247: "Architectural enhancements for 5G multicast-broadcast services; Stage 2".
[47]
TS 26.247: "Transparent end-to-end Packet-switched Streaming Service (PSS); Progressive Download and Dynamic Adaptive Streaming over HTTP (3GP-DASH)".
[48]
TS 23.304: "Proximity based Services (ProSe) in the 5G System (5GS)".
[49]
TS 38.455: "NG-RAN; NR Positioning Protocol A (NRPPa)".
[50]
TS 29.571: "5G System; Common Data Types for Service Based Interfaces; Stage 3".
[51]
TS 37.213: "NR; Physical layer procedures for shared spectrum channel access".
[52]
TS 38.101-1: "NR; User Equipment (UE) radio transmission and reception; Part 1: Range 1 Standalone".
[53]
TS 26.114: "IP Multimedia Subsystem (IMS); Multimedia Telephony; Media handling and interaction".
[54]
TS 26.118: "Virtual Reality (VR) profiles for streaming applications".
[55]
TS 28.405: "Telecommunication management; Quality of Experience (QoE) measurement collection; Control and configuration".
[56]
TS 23.256: "Support of Uncrewed Aerial Systems (UAS) connectivity, identification and tracking; Stage 2".
[57]
TS 23.527: "5G System; Restoration procedures".
3 Definitions, symbols and abbreviations p. 19
3.1 Definitions p. 19
For the purposes of the present document, the terms and definitions given in TR 21.905 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905.
Boundary IAB-node:
as defined in TS 38.401.
CAG Cell:
As defined in TS 38.300.
Conditional Handover:
As defined in TS 38.300.
Conditional PSCell Change:
As defined in TS 37.340.
DAPS Handover:
As defined in TS 38.300.
Elementary Procedure:
XnAP protocol consists of Elementary Procedures (EPs). An XnAP Elementary Procedure is a unit of interaction between two NG-RAN nodes. An EP consists of an initiating message and possibly a response message. Two kinds of EPs are used:
F1-terminating IAB-donor:
- Class 1: Elementary Procedures with response (success or failure),
- Class 2: Elementary Procedures without response.
as defined in TS 38.401.
Immediate Handover:
Used in the context of Conditional Handover, to refer to a handover that is executed immediately after the UE receives the Handover Command.
MBS Session Resource:
As defined in TS 38.401.
Mobile IAB-node:
as defined in TS 38.300.
Mobile IAB-MT:
as defined in TS 38.300.
NG-RAN MBS session resource context:
as defined in TS 38.401.
NG-RAN node:
as defined in TS 38.300.
Non-CAG Cell:
As defined in TS 38.300.
Non-F1-terminating IAB-donor:
as defined in TS 38.401.
PDU Session Resource:
As defined in TS 38.401.
PDU session split:
as defined in TS 37.340.
Public Network Integrated NPN:
as defined in TS 23.501.
RRC-terminating IAB-donor:
as defined in TS 38.401.
Stand-alone Non-Public Network:
as defined in TS 23.501.
Subsequent Conditional PSCell Addition or Change (Subsequent CPAC):
as defined in TS 37.340.
3.2 Abbreviations p. 20
For the purposes of the present document, the abbreviations given in TR 21.905 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905.
5QI
5G QoS Identifier
AI
Artificial Intelligence
AMF
Access and Mobility Management Function
A2X
Aircraft-to-Everything
BH
Backhaul
CAG
Closed Access Group
CGI
Cell Global Identifier
CHO
Conditional Handover
CP
Control Plane
CPA
Conditional PSCell Addition
CPAC
Conditional PSCell Addition or Change
CPC
Conditional PSCell Change
DAPS
Dual Active Protocol Stack
DL
Downlink
EN-DC
E-UTRA-NR Dual Connectivity
E-RAB
E-UTRAN Radio Access Bearer
GUAMI
Globally Unique AMF Identifier
IAB
Integrated Access and Backhaul
IMEISV
International Mobile station Equipment Identity and Software Version number
LBT
Listen-Before-Talk
MBS
Multicast/Broadcast Service
MCG
Master Cell Group
ML
Machine Learning
MT-SDT
Mobile Terminated Small Data Transmission
M-NG-RAN node
Master NG-RAN node
NGAP
NG Application Protocol
NID
Network Identifier
NPN
Non-Public Network
NSAG
Network Slice AS Group
NSSAI
Network Slice Selection Assistance Information
PEIPS
Paging Early Indication with Paging Subgrouping
PNI-NPN
Public Network Integrated Non-Public Network
ProSe
Proximity Services
RANAC
RAN Area Code
RedCap
Reduced Capability
RSN
Redundancy Sequence Number
RSPP
Ranging/SL Positioning Protocol
SCG
Secondary Cell Group
SCTP
Stream Control Transmission Protocol
SNPN
Stand-alone Non-Public Network
S-CPAC
Subsequent CPAC
S-NG-RAN node
Secondary NG-RAN node
S-NSSAI
Single Network Slice Selection Assistance Information
SUL
Supplementary Uplink
SDT
Small Data Transmission
TAC
Tracking Area Code
TAI
Tracking Area Identity
UL
Uplink
UPF
User Plane Function
V2X
Vehicle-to-Everything
