3 Abbreviations and Definitions
38.3003GPPNRNR and NG-RAN Overall descriptionRelease 17Stage 2TS
3.1 Abbreviations
For the purposes of the present document, the abbreviations given in TR 21.905 [1], in TS 36.300 [2] 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 [1] and TS 36.300 [2].
5GC 5G Core Network
5GS 5G System
5QI 5G QoS Identifier
A-CSI Aperiodic CSI
AGC Automatic Gain Control
AKA Authentication and Key Agreement
AMBR Aggregate Maximum Bit Rate
AMC Adaptive Modulation and Coding
AMF Access and Mobility Management Function
ARP Allocation and Retention Priority
BA Bandwidth Adaptation
BCCH Broadcast Control Channel
BCH Broadcast Channel
BFD Beam Failure Detection
BH Backhaul
BL Bandwidth reduced Low complexity
BPSK Binary Phase Shift Keying
C-RNTI Cell RNTI
CAG Closed Access Group
CAPC Channel Access Priority Class
CBRA Contention Based Random Access
CCE Control Channel Element
CD-SSB Cell Defining SSB
CFRA Contention Free Random Access
CG Configured Grant
CHO Conditional Handover
CIoT Cellular Internet of Things
CLI Cross Link interference
CMAS Commercial Mobile Alert Service
CORESET Control Resource Set
CP Cyclic Prefix
CPA Conditional PSCell Addition
CPC Conditional PSCell Change
DAG Directed Acyclic Graph
DAPS Dual Active Protocol Stack
DFT Discrete Fourier Transform
DCI Downlink Control Information
DCP DCI with CRC scrambled by PS-RNTI
DL-AoD Downlink Angle-of-Departure
DL-SCH Downlink Shared Channel
DL-TDOA Downlink Time Difference Of Arrival
DMRS Demodulation Reference Signal
DRX Discontinuous Reception
E-CID Enhanced Cell-ID (positioning method)
EHC Ethernet Header Compression
ETWS Earthquake and Tsunami Warning System
FS Feature Set
FSA ID Frequency Selection Area Identity
G-CS-RNTI Group Configured Scheduling RNTI
G-RNTI Group RNTI
GFBR Guaranteed Flow Bit Rate
GIN Group ID for Network selection
GSO Geosynchronous Orbit
H-SFN Hyper System Frame Number
HAPS High Altitude Platform Station
HRNN Human-Readable Network Name
IAB Integrated Access and Backhaul
IFRI Intra Frequency Reselection Indication
I-RNTI Inactive RNTI
INT-RNTI Interruption RNTI
KPAS Korean Public Alarm System
L2 Layer-2
L3 Layer-3
LDPC Low Density Parity Check
LEO Low Earth Orbit
MBS Multicast/Broadcast Services
MCE Measurement Collection Entity
MCCH MBS Control Channel
MDBV Maximum Data Burst Volume
MEO Medium Earth Orbit
MIB Master Information Block
MICO Mobile Initiated Connection Only
MFBR Maximum Flow Bit Rate
MMTEL Multimedia telephony
MNO Mobile Network Operator
MPE Maximum Permissible Exposure
MRB MBS Radio Bearer
MT Mobile Termination
MTCH MBS Traffic Channel
MTSI Multimedia Telephony Service for IMS
MU-MIMO Multi User MIMO
Multi-RTT Multi-Round Trip Time
MUSIM Multi-Universal Subscriber Identity Module
NB-IoT Narrow Band Internet of Things
NCD-SSB Non Cell Defining SSB
NCGI NR Cell Global Identifier
NCL Neighbour Cell List
NCR Neighbour Cell Relation
NCRT Neighbour Cell Relation Table
NGAP NG Application Protocol
NGSO Non-Geosynchronous Orbit
NID Network Identifier
NPN Non-Public Network
NR NR Radio Access
NSAG Network Slice AS Group
NTN Non-Terrestrial Network
P-MPR Power Management Maximum Power Reduction
P-RNTI Paging RNTI
PCH Paging Channel
PCI Physical Cell Identifier
PDC Propagation Delay Compensation
PDCCH Physical Downlink Control Channel
PDSCH Physical Downlink Shared Channel
PEI Paging Early Indication
PH Paging Hyperframe
PLMN Public Land Mobile Network
PNI-NPN Public Network Integrated NPN
PO Paging Occasion
PRACH Physical Random Access Channel
PRB Physical Resource Block
PRG Precoding Resource block Group
PRS Positioning Reference Signal
PS-RNTI Power Saving RNTI
PSS Primary Synchronisation Signal
PTM Point to Multipoint
PTP Point to Point
PTW Paging Time Window
PUCCH Physical Uplink Control Channel
PUSCH Physical Uplink Shared Channel
PWS Public Warning System
QAM Quadrature Amplitude Modulation
QFI QoS Flow ID
QMC QoE Measurement Collection
QoE Quality of Experience
QPSK Quadrature Phase Shift Keying
RA Random Access
RA-RNTI Random Access RNTI
RACH Random Access Channel
RANAC RAN-based Notification Area Code
REG Resource Element Group
RIM Remote Interference Management
RLM Radio Link Monitoring
RMSI Remaining Minimum SI
RNA RAN-based Notification Area
RNAU RAN-based Notification Area Update
RNTI Radio Network Temporary Identifier
RQA Reflective QoS Attribute
RQoS Reflective Quality of Service
RS Reference Signal
RSRP Reference Signal Received Power
RSRQ Reference Signal Received Quality
RSSI Received Signal Strength Indicator
RSTD Reference Signal Time Difference
RTT Round Trip Time
SCS SubCarrier Spacing
SD Slice Differentiator
SDAP Service Data Adaptation Protocol
SDT Small Data Transmission
SFI-RNTI Slot Format Indication RNTI
SHR Successful Handover Report
SIB System Information Block
SI-RNTI System Information RNTI
SLA Service Level Agreement
SMC Security Mode Command
SMF Session Management Function
S-NSSAI Single Network Slice Selection Assistance Information
SNPN Stand-alone Non-Public Network
SNPN ID Stand-alone Non-Public Network Identity
SPS Semi-Persistent Scheduling
SR Scheduling Request
SRAP Sidelink Relay Adaptation Protocol
SRS Sounding Reference Signal
SRVCC Single Radio Voice Call Continuity
SS Synchronization Signal
SSB SS/PBCH block
SSS Secondary Synchronisation Signal
SSSG Search Space Set Group
SST Slice/Service Type
SU-MIMO Single User MIMO
SUL Supplementary Uplink
TA Timing Advance
TB Transport Block
TCE Trace Collection Entity
TNL Transport Network Layer
TPC Transmit Power Control
TRP Transmit/Receive Point
TRS Tracking Reference Signal
U2N UE-to-Network
UCI Uplink Control Information
UDC Uplink Data Compression
UE-Slice-MBR UE Slice Maximum Bit Rate
UL-AoA Uplink Angles of Arrival
UL-RTOA Uplink Relative Time of Arrival
UL-SCH Uplink Shared Channel
UPF User Plane Function
URLLC Ultra-Reliable and Low Latency Communications
VR Virtual Reality
V2X Vehicle-to-Everything
Xn-C Xn-Control plane
Xn-U Xn-User plane
XnAP Xn Application Protocol
3.2 Definitions
For the purposes of the present document, the terms and definitions given in TR 21.905 [1], in TS 36.300 [2] 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 [1] and TS 36.300 [2].
BH RLC channel: an RLC channel between two nodes, which is used to transport backhaul packets.
Boundary IAB-node: as defined in TS 38.401 [4].
CAG Cell: a PLMN cell broadcasting at least one Closed Access Group identity.
CAG Member Cell: for a UE, a CAG cell broadcasting the identity of the selected PLMN, registered PLMN or equivalent PLMN, and for that PLMN, a CAG identifier belonging to the Allowed CAG list of the UE for that PLMN.
CAG-only cell: a CAG cell that is only available for normal service for CAG UEs.
Cell-Defining SSB: an SSB with an RMSI associated.
Child node: IAB-DU’s and IAB-donor-DU’s next hop neighbour node; the child node is also an IAB-node.
Conditional Handover (CHO): a handover procedure that is executed only when execution condition(s) are met.
CORESET#0: the control resource set for at least SIB1 scheduling, can be configured either via MIB or via dedicated RRC signalling.
DAPS Handover: a handover procedure that maintains the source gNB connection after reception of RRC message for handover and until releasing the source cell after successful random access to the target gNB.
Direct Path: a type of UE-to-Network transmission path, where data is transmitted between a UE and the network without sidelink relaying.
Downstream: direction toward child node or UE in IAB-topology.
Early Data Forwarding: data forwarding that is initiated before the UE executes the handover.
Earth-centered, earth-fixed: a global geodetic reference system for the Earth intended for practical applications of mapping, charting, geopositioning and navigation, as specified in NIMA TR 8350.2 [51].
Feeder link: wireless link between the NTN Gateway and the NTN payload.
Geosynchronous Orbit: earth-centered orbit at approximately 35786 kilometres above Earth’s surface and synchronised with Earth’s rotation. A geostationary orbit is a non-inclined geosynchronous orbit, i.e. in the Earth’s equator plane.
Group ID for Network Selection: an identifier used during SNPN selection to enhance the likelihood of selecting a preferred SNPN that supports a Default Credentials Server or a Credentials Holder, as specified in TS 23.501 [3].
gNB: node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC.
High Altitude Platform Station: airborne vehicle embarking the NTN payload placed at an altitude between 8 and 50 km.
IAB-donor: gNB that provides network access to UEs via a network of backhaul and access links.
IAB-donor-CU: as defined in TS 38.401 [4].
IAB-donor-DU: as defined in TS 38.401 [4].
IAB-DU: gNB-DU functionality supported by the IAB-node to terminate the NR access interface to UEs and next-hop IAB-nodes, and to terminate the F1 protocol to the gNB-CU functionality, as defined in TS 38.401 [4], on the IAB-donor.
IAB-MT: IAB-node function that terminates the Uu interface to the parent node using the procedures and behaviours specified for UEs unless stated otherwise. IAB-MT function used in 38-series of 3GPP Specifications corresponds to IAB-UE function defined in TS 23.501 [3].
IAB-node: RAN node that supports NR access links to UEs and NR backhaul links to parent nodes and child nodes. The IAB-node does not support backhauling via LTE.
IAB topology: the unison of all IAB-nodes and IAB-donor-DUs that are interconnected via BH links and terminate F1 and/or RRC at the same IAB-donor-CU.
Indirect Path: a type of UE-to-Network transmission path, where data is forwarded via a U2N Relay UE between a U2N Remote UE and the network.
Inter-donor partial migration: migration of an IAB-MT to a parent node underneath a different IAB-donor-CU while the collocated IAB-DU and its descendant IAB-node(s), if any, are terminated at the initial IAB-donor-CU. The procedure renders the said IAB-node as a boundary IAB-node.
Intra-system Handover: handover that does not involve a CN change (EPC or 5GC).
Inter-system Handover: handover that involves a CN change (EPC or 5GC).
Late Data Forwarding: data forwarding that is initiated after the source NG-RAN node knows that the UE has successfully accessed a target NG-RAN node.
Mapped Cell ID: in NTN, it corresponds to a fixed geographical area.
MSG1: preamble transmission of the random access procedure for 4-step random access (RA) type.
MSG3: first scheduled transmission of the random access procedure.
MSGA: preamble and payload transmissions of the random access procedure for 2-step RA type.
MSGB: response to MSGA in the 2-step random access procedure. MSGB may consist of response(s) for contention resolution, fallback indication(s), and backoff indication.
Multi-hop backhauling: using a chain of NR backhaul links between an IAB-node and an IAB-donor.
ng-eNB: node providing E-UTRA user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC.
NG-C: control plane interface between NG-RAN and 5GC.
NG-U: user plane interface between NG-RAN and 5GC.
NG-RAN node: either a gNB or an ng-eNB.
Non-CAG Cell: a PLMN cell which does not broadcast any Closed Access Group identity.
Non-Geosynchronous orbit: earth-centered orbit with an orbital period that does not match Earth’s rotation on its axis. This includes Low and Medium Earth Orbit (LEO and MEO). LEO operates at altitudes between 300 km and 1500 km and MEO at altitudes between 7000 km and 25000 km, approximately.
Non-terrestrial network: an NG-RAN consisting of gNBs, which provide non-terrestrial NR access to UEs by means of an NTN payload embarked on an airborne or space-borne NTN vehicle and an NTN Gateway.
NR backhaul link: NR link used for backhauling between an IAB-node and an IAB-donor, and between IAB-nodes in case of a multi-hop backhauling.
NR sidelink communication: AS functionality enabling at least V2X communication as defined in TS 23.287 [40] and the ProSe communication (including ProSe non-Relay and UE-to-Network Relay communication) as defined in TS 23.304 [48], between two or more nearby UEs, using NR technology but not traversing any network node.
NR sidelink discovery: AS functionality enabling ProSe non-Relay Discovery and ProSe UE-to-Network Relay discovery for Proximity based Services as defined in TS 23.304 [48] between two or more nearby UEs, using NR technology but not traversing any network node.
NTN Gateway: an earth station located at the surface of the earth, providing connectivity to the NTN payload using the feeder link. An NTN Gateway is a TNL node.
NTN payload: a network node, embarked on board a satellite or high altitude platform station, providing connectivity functions, between the service link and the feeder link. In the current version of this specification, the NTN payload is a TNL node.
Numerology: corresponds to one subcarrier spacing in the frequency domain. By scaling a reference subcarrier spacing by an integer N, different numerologies can be defined.
Parent node: IAB-MT’s next hop neighbour node; the parent node can be IAB-node or IAB-donor-DU
PC5 Relay RLC channel: an RLC channel between L2 U2N Remote UE and L2 U2N Relay UE, which is used to transport packets over PC5 for L2 UE-to-Network Relay.
PLMN Cell: a cell of the PLMN.
RedCap UE: a UE with reduced capabilities as specified in clause 4.2.21.1 in TS 38.306 [11].
Relay discovery: AS functionality enabling 5G ProSe UE-to-Network Relay Discovery as defined in TS 23.304 [48], using NR technology but not traversing any network node.
Satellite: a space-borne vehicle orbiting the Earth embarking the NTN payload.
Service link: wireless link between the NTN payload and UE.
SNPN Access Mode: mode of operation whereby a UE only accesses SNPNs.
SNPN-only cell: a cell that is only available for normal service for SNPN subscribers.
SNPN Identity: the identity of Stand-alone NPN defined by the pair (PLMN ID, NID).
Transmit/Receive Point: part of the gNB transmitting and receiving radio signals to/from UE according to physical layer properties and parameters inherent to that element.
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.
Upstream: direction toward parent node in IAB-topology.
Uu Relay RLC channel: an RLC channel between L2 U2N Relay UE and gNB, which is used to transport packets over Uu for L2 UE-to-Network Relay.
V2X sidelink communication: AS functionality enabling V2X communication as defined in TS 23.285 [41], between nearby UEs, using E-UTRA technology but not traversing any network node.
Xn: network interface between NG-RAN nodes.