Content for TS 38.473 Word version: 18.2.0
1 Scope p. 21
The present document specifies the 5G radio network layer signalling protocol for the F1 interface. The F1 interface provides means for interconnecting a gNB-CU and a gNB-DU of a gNB within an NG-RAN, or for interconnecting a gNB-CU and a gNB-DU of an en-gNB within an E-UTRAN. The F1 Application Protocol (F1AP) supports the functions of F1 interface by signalling procedures defined in the present document. F1AP is developed in accordance to the general principles stated in TS 38.401 and TS 38.470.
2 References p. 21
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 38.470: "NG-RAN; F1 general aspects and principles".
[3]
TS 38.413: "NG-RAN; NG Application Protocol (NGAP)".
[4]
TS 38.401: "NG-RAN; Architecture Description".
[5]
ITU-T Recommendation X.691 (2002-07): "Information technology - ASN.1 encoding rules - Specification of Packed Encoding Rules (PER)".
[6]
TS 38.300: "NR; Overall description; Stage-2".
[7]
TS 37.340: "NR; Multi-connectivity; Overall description; Stage-2".
[8]
TS 38.331: "NR; Radio Resource Control (RRC); Protocol specification".
[9]
TS 36.423: "Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 Application Protocol (X2AP)".
[10]
TS 23.401: "General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access".
[11]
TS 23.203: "Policy and charging control architecture".
[12]
ITU-T Recommendation X.680 (07/2002): "Information technology - Abstract Syntax Notation One (ASN.1): Specification of basic notation".
[13]
ITU-T Recommendation X.681 (07/2002): "Information technology - Abstract Syntax Notation One (ASN.1): Information object specification".
[14]
TR 25.921: (version.7.0.0): "Guidelines and principles for protocol description and error".
[15]
TS 36.413: "Evolved Universal Terrestrial Radio Access Network (E-UTRAN); S1 Application Protocol (S1AP)".
[16]
TS 38.321: "NR; Medium Access Control (MAC) protocol specification".
[17]
TS 38.104: "NR; Base Station (BS) radio transmission and reception".
[18]
TS 29.281: "General Packet Radio System (GPRS); Tunnelling Protocol User Plane (GTPv1-U) ".
[19]
TS 38.414: "NG-RAN; NG data transport".
[20]
TS 36.300: "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2".
[21]
TS 23.501: "System Architecture for the 5G System".
[22]
TS 38.472: "NG-RAN; F1 signalling transport".
[23]
TS 23.003: "Numbering, addressing and identification".
[24]
TS 38.304: "NR; User Equipment (UE) procedures in Idle mode and RRC Inactive state ".
[25]
TS 36.104: "Base Station (BS) radio transmission and reception".
[26]
TS 38.101-1: "NR; User Equipment (UE) radio transmission and reception; Part 1: Range 1 Standalone".
[27]
TS 36.211: "Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and modulation".
[28]
TS 38.423: "NG-RAN; Xn application protocol (XnAP)".
[29]
TS 32.422: "Trace control and configuration management".
[30]
TS 38.340: "NR; Backhaul Adaptation Protocol (BAP) specification".
[31]
TS 38.213: "NR; Physical layer procedures for control".
[32]
TS 38.314: "NR; Layer 2 measurements".
[33]
TS 38.211: "NR; Physical channels and modulation".
[34]
TS 38.214: "NR; Physical layer procedures for data".
[35]
TS 37.320: "Radio measurement collection for Minimization of Drive Tests (MDT)".
[36]
TS 23.032: "Technical Specification Group Services and System Aspects; Universal Geographical Area Description (GAD)".
[37]
TS 38.455: "NG-RAN; NR Positioning protocol A (NRPPa)".
[38]
TS 38.133: "NR; Requirements for support of radio resource management".
[39]
TS 37.355: "LTE Positioning Protocol (LPP)".
[40]
TS 23.287: "Architecture enhancements for 5G System (5GS) to support Vehicle-to-Everything (V2X) services".
[41]
TS 36.331: "Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification".
[42]
TS 38.305: "NG Radio Access Network (NG-RAN); Stage 2 functional specification of User Equipment (UE) positioning in NG-RAN".
[43]
TS 38.215: "NR; Physical layer (PHY); Measurements".
[44]
TS 23.304: "Proximity based Services (ProSe) in the 5G System (5GS)".
[45] Void
[46]
TS 37.213: "NR; Physical layer procedures for shared spectrum channel access".
[47]
TS 37.483: "E1 Application Protocol (E1AP)".
[48]
IEEE Std 1588: "IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems", Edition 2019.
[49]
TS 23.273: "5G System (5GS) Location Services (LCS); Stage 2".
[50]
TS 29.571: "5G System; Common Data Types for Service Based Interfaces; Stage 3".
3 Definitions and abbreviations p. 23
3.1 Definitions p. 23
elementary procedure:
F1AP consists of Elementary Procedures (EPs). An Elementary Procedure is a unit of interaction between gNB-CU and gNB-DU. These Elementary Procedures are defined separately and are intended to be used to build up complete sequences in a flexible manner. If the independence between some EPs is restricted, it is described under the relevant EP description. Unless otherwise stated by the restrictions, the EPs may be invoked independently of each other as standalone procedures, which can be active in parallel. The usage of several F1AP EPs together is specified in stage 2 specifications (e.g., TS 38.470).
An EP consists of an initiating message and possibly a response message. Two kinds of EPs are used:
BH RLC channel:
- Class 1: Elementary Procedures with response (success and/or failure).
- Class 2: Elementary Procedures without response.
Successful:
Class 2 EPs are considered always successful.
- A signalling message explicitly indicates that the elementary procedure successfully completed with the receipt of the response.
- A signalling message explicitly indicates that the EP failed.
- On time supervision expiry (i.e., absence of expected response).
- One signalling message reports both successful and unsuccessful outcome for the different included requests. The response message used is the one defined for successful outcome.
as defined in TS 38.300.
CG-SDT-CS-RNTI:
as defined in TS 38.300.
Conditional handover:
as defined in TS 38.300.
Conditional PSCell Addition:
as defined in TS 37.340.
Conditional PSCell Change:
as defined in TS 37.340.
DAPS Handover:
as defined in TS 38.300.
EN-DC operation:
Used in this specification when the F1AP is applied for gNB-CU and gNB-DU in E-UTRAN.
F1-terminating IAB-donor:
as defined in TS 38.401.
gNB:
as defined in TS 38.300.
gNB-CU:
as defined in TS 38.401.
gNB-CU UE F1AP ID:
as defined in TS 38.401.
gNB-DU:
as defined in TS 38.401.
gNB-DU UE F1AP ID:
as defined in TS 38.401.
en-gNB:
as defined in TS 37.340.
IAB-DU:
as defined in TS 38.300.
IAB-MT:
as defined in TS 38.300.
IAB-donor:
as defined in TS 38.300.
IAB-donor-CU:
as defined in TS 38.401.
IAB-donor-DU:
as defined in TS 38.401.
IAB-node:
as defined in TS 38.300.
MBS-associated signalling:
When F1AP messages associated to one MBS session uses the MBS-associated logical F1-connection for association of the message to the MBS session in gNB-DU and gNB-CU.
MBS-associated logical F1-connection:
The MBS-associated logical F1-connection uses the identities GNB-CU MBS F1AP ID and GNB-DU MBS F1AP ID according to the definition in TS 38.401. For a received MBS-associated F1AP message the gNB-CU identifies the associated MBS session based on the GNB-CU MBS F1AP ID IE and the gNB-DU identifies the associated MBS session based on the GNB-DU MBS F1AP ID IE.
MBS Session context in a gNB-DU:
as defined in TS 38.401.
MBS session resource:
as defined in TS 38.401.
Mobile IAB-DU:
as defined in TS 38.300.
Mobile IAB-MT:
as defined in TS 38.300.
Mobile IAB-node:
as defined in TS 38.300.
MP Relay UE:
as defined in TS 38.300.
MP Remote UE:
as defined in TS 38.300.
Multi-path:
as defined in TS 38.300.
Multicast F1-U Context:
as defined in TS 38.401.
Other SI:
as defined in TS 38.300.
PC5 Relay RLC channel:
as defined in TS 38.300.
Public network integrated NPN:
as defined in TS 23.501.
RRC-terminating IAB-donor:
as defined in TS 38.401.
SRAP:
Sidelink relay adaptation protocol, as defined in TS 38.300.
Stand-alone Non-Public Network:
as defined in TS 23.501.
UE-associated logical F1-connection:
The UE-associated logical F1-connection uses the identities GNB-CU UE F1AP ID and GNB-DU UE F1AP ID according to the definition in TS 38.401. For a received UE associated F1AP message the gNB-CU identifies the associated UE based on the GNB-CU UE F1AP ID IE and the gNB-DU identifies the associated UE based on the GNB-DU UE F1AP ID IE. The UE-associated logical F1-connection may exist before the F1 UE context is setup in gNB-DU.
UE-associated signalling:
When F1AP messages associated to one UE uses the UE-associated logical F1-connection for association of the message to the UE in gNB-DU and gNB-CU.
U2N Relay UE:
a UE that provides functionality to support connectivity to the network for U2N Remote UE(s).
U2N Remote UE:
a UE that communicates with the network via a U2N Relay UE.
U2U Relay UE:
as defined in TS 38.300.
U2U Remote UE:
as defined in TS 38.300.
Uu Relay RLC channel:
as defined in TS 38.300.
3.2 Abbreviations p. 25
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.
5GC
5G Core Network
5QI
5G QoS Identifier
A2X
Aircraft-to-Everything
AMF
Access and Mobility Management Function
ARP
Antenna Reference Point
ARPI
Additional RRM Policy Index
BH
Backhaul
CAG
Closed Access Group
CG
Cell Group
CG-SDT
Configured Grant-Small Data Transmission
CGI
Cell Global Identifier
CHO
Conditional Handover
CN
Core Network
CP
Control Plane
CPA
Conditional PSCell Addition
CPAC
Conditional PSCell Addition or Change
CPC
Conditional PSCell Change
DAPS
Dual Active Protocol Stack
DL
Downlink
DL-PRS
Downlink Positioning Reference Signal
EN-DC
E-UTRA-NR Dual Connectivity
EPC
Evolved Packet Core
eRedCap
Enhanced Reduced Capability
FSA ID
MBS Frequency Selection Area (FSA) ID
GPSI
Generic Public Subscription Identifier
IAB
Integrated Access and Backhaul
IMEISV
International Mobile station Equipment Identity and Software Version number
LMF
Location Management Function
LTM
L1/L2 Triggered Mobility
MBS
Multicast/Broadcast Service
MP
Multi-path
MT-SDT
Mobile Terminated Small Data Transmission
N3C
Non-3GPP Connection
NID
Network Identifier
NPN
Non-Public Network
NSAG
Network Slice AS Group
NSSAI
Network Slice Selection Assistance Information
PDC
Propagation Delay Compensation
PEIPS
Paging Early Indication with Paging Subgrouping
PNI-NPN
Public Network Integrated NPN
posSIB
Positioning SIB
PSI
PDU Set Importance
PTM
Point to Multipoint
PTP
Point to Point
QMC
QoE Measurement Collection
QoE
Quality of Experience
RANAC
RAN Area Code
RedCap
Reduced Capability
RIM
Remote Interference Management
RIM-RS
RIM Reference Signal
RRC
Radio Resource Control
RSPP
Ranging/Sidelink Positioning Protocol
RSRP
Reference Signal Received Power
S-CPAC
Subsequent Conditional PSCell Addition or Change
S-NSSAI
Single Network Slice Selection Assistance Information
SDT
Small Data Transmission
SNPN
Stand-alone Non-Public Network
SUL
Supplementary Uplink
TAC
Tracking Area Code
TAI
Tracking Area Identity
TEG
Timing Error Group
TRP
Transmission-Reception Point
TSS
Timing Synchronisation Status
U2N
UE-to-Network
U2U
UE-to-UE
UL-AoA
Uplink Angle of Arrival
UL-RSCP
UL Reference Signal Carrier Phase
UL-RTOA
Uplink Relative Time of Arrival
UL-SRS
Uplink Sounding Reference Signal
V2X
Vehicle-to-Everything
Z-AoA
Zenith Angles of Arrival
