For the purposes of the present document, the abbreviations given in TR 21.905
, in TS 36.300
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
and TS 36.300
5G Core Network
5G QoS Identifier
Automatic Gain Control
Authentication and Key Agreement
Aggregate Maximum Bit Rate
Adaptive Modulation and Coding
Access and Mobility Management Function
Allocation and Retention Priority
Broadcast Control Channel
Beam Failure Detection
Bandwidth reduced Low complexity
Binary Phase Shift Keying
Closed Access Group
Channel Access Priority Class
Contention Based Random Access
Control Channel Element
Cell Defining SSB
Common Frequency Resource
Contention Free Random Access
Cellular Internet of Things
Cross Link interference
Commercial Mobile Alert Service
Control Resource Set
Conditional PSCell Addition
Conditional PSCell Change
Directed Acyclic Graph
Dual Active Protocol Stack
Discrete Fourier Transform
Downlink Control Information
DCI with CRC scrambled by PS-RNTI
Downlink Shared Channel
Downlink Time Difference Of Arrival
Demodulation Reference Signal
Enhanced Cell-ID (positioning method)
Ethernet Header Compression
enhancements of Public Warning System
Earthquake and Tsunami Warning System
Frequency Selection Area Identity
Group Configured Scheduling RNTI
Guaranteed Flow Bit Rate
Group ID for Network selection
Global Navigation Satellite System
Hyper System Frame Number
High Altitude Platform Station
Human-Readable Network Name
Integrated Access and Backhaul
Intra Frequency Reselection Indication
Korean Public Alarm System
Low Density Parity Check
Low Earth Orbit
Measurement Collection Entity
MBS Control Channel
Maximum Data Burst Volume
Medium Earth Orbit
Master Information Block
Mobile Initiated Connection Only
Maximum Flow Bit Rate
Mobile Network Operator
Maximum Permissible Exposure
MBS Radio Bearer
MBS Traffic Channel
Multimedia Telephony Service for IMS
Multi User MIMO
Multi-Round Trip Time
Multi-Universal Subscriber Identity Module
Narrow Band Internet of Things
Non Cell Defining SSB
NR Cell Global Identifier
Neighbour Cell List
Neighbour Cell Relation
Neighbour Cell Relation Table
NG Application Protocol
NR Radio Access
Network Slice AS Group
Power Management Maximum Power Reduction
Physical Cell Identifier
Propagation Delay Compensation
Physical Downlink Control Channel
Physical Downlink Shared Channel
Paging Early Indication
Public Land Mobile Network
Public Network Integrated NPN
Physical Random Access Channel
Physical Resource Block
Precoding Resource block Group
Positioning Reference Signal
Power Saving RNTI
Primary Synchronisation Signal
Point to Multipoint
Point to Point
Paging Time Window
Physical Uplink Control Channel
Physical Uplink Shared Channel
Public Warning System
Quadrature Amplitude Modulation
QoS Flow ID
QoE Measurement Collection
Quality of Experience
Quadrature Phase Shift Keying
Random Access RNTI
Random Access Channel
RAN-based Notification Area Code
Resource Element Group
Remote Interference Management
Radio Link Monitoring
Remaining Minimum SI
RAN-based Notification Area
RAN-based Notification Area Update
Radio Network Temporary Identifier
Reflective QoS Attribute
Reflective Quality of Service
Reference Signal Received Power
Reference Signal Received Quality
Received Signal Strength Indicator
Reference Signal Time Difference
Round Trip Time
Service Data Adaptation Protocol
Small Data Transmission
Sidelink Discovery RSRP
Slot Format Indication RNTI
Successful Handover Report
System Information Block
System Information RNTI
Service Level Agreement
Security Mode Command
Session Management Function
SS/PBCH block Measurement Timing Configuration
Single Network Slice Selection Assistance Information
Stand-alone Non-Public Network
Stand-alone Non-Public Network Identity
Sidelink Relay Adaptation Protocol
Sounding Reference Signal
Single Radio Voice Call Continuity
Secondary Synchronisation Signal
Search Space Set Group
Single User MIMO
Trace Collection Entity
Transport Network Layer
Transmit Power Control
Tracking Reference Signal
Uplink Control Information
Uplink Data Compression
UE Slice Maximum Bit Rate
Uplink Angles of Arrival
Uplink Relative Time of Arrival
Uplink Shared Channel
User Plane Function
Ultra-Reliable and Low Latency Communications
Xn Application Protocol
For the purposes of the present document, the terms and definitions given in TR 21.905
, in TS 36.300
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
and TS 36.300
BH RLC channel:
an RLC channel between two nodes, which is used to transport backhaul packets.
A radio bearer configured for MBS broadcast delivery.
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.
a CAG cell that is only available for normal service for CAG UEs.
an SSB with an RMSI associated.
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.
the control resource set for at least SIB1 scheduling, can be configured either via MIB or via dedicated RRC signalling.
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.
a type of UE-to-Network transmission path, where data is transmitted between a UE and the network without sidelink relaying.
direction toward child node or UE in IAB-topology.
Early Data Forwarding:
data forwarding that is initiated before the UE executes the handover.
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 
wireless link between the NTN Gateway and the NTN payload.
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
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.
gNB that provides network access to UEs via a network of backhaul and access links.
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
, on the IAB-donor.
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
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.
the unison of all IAB-nodes and IAB-donor-DUs whose F1 and/or RRC connections are terminated at the same IAB-donor-CU.
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.
handover that does not involve a CN change (EPC or 5GC).
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.
MBS Radio Bearer:
A radio bearer configured for MBS delivery.
preamble transmission of the random access procedure for 4-step random access (RA) type.
first scheduled transmission of the random access procedure.
preamble and payload transmissions of the random access procedure for 2-step RA type.
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.
A point-to-multipoint service as defined in TS 23.247
A radio bearer configured for MBS multicast delivery.
using a chain of NR backhaul links between an IAB-node and an IAB-donor.
node providing E-UTRA user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC.
control plane interface between NG-RAN and 5GC.
user plane interface between NG-RAN and 5GC.
either a gNB or an ng-eNB.
a PLMN cell which does not broadcast any Closed Access Group identity.
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.
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:
NR sidelink discovery:
AS functionality enabling at least V2X communication as defined in TS 23.287
and the ProSe communication (including ProSe non-Relay and UE-to-Network Relay communication) as defined in TS 23.304
, between two or more nearby UEs, using NR technology but not traversing any network node.
AS functionality enabling ProSe non-Relay Discovery and ProSe UE-to-Network Relay discovery for Proximity based Services as defined in TS 23.304
between two or more nearby UEs, using NR technology but not traversing any network node.
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.
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.
corresponds to one subcarrier spacing in the frequency domain. By scaling a reference subcarrier spacing by an integer N, different numerologies can be defined.
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.
a cell of the PLMN.
AS functionality enabling 5G ProSe UE-to-Network Relay Discovery as defined in TS 23.304
, using NR technology but not traversing any network node.
a space-borne vehicle orbiting the Earth embarking the NTN payload.
wireless link between the NTN payload and UE.
Sidelink Discovery RSRP:
RSRP measurements on PC5 link related to NR sidelink discovery.
RSRP measurements on PC5 link related to NR sidelink communication.
SNPN Access Mode:
mode of operation whereby a UE only accesses SNPNs.
a cell that is only available for normal service for SNPN subscribers.
the identity of Stand-alone NPN defined by the pair (PLMN ID, NID).
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.
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
, between nearby UEs, using E-UTRA technology but not traversing any network node.
network interface between NG-RAN nodes.