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
As used in this document, the suffixes "-based"
refer respectively to the node that is responsible for making the positioning calculation (and which may also provide measurements) and a node that provides measurements (but which does not make the positioning calculation). Thus, an operation in which measurements are provided by the UE to the LMF to be used in the computation of a position estimate is described as "UE-assisted"
(and could also be called "LMF-based"
), while one in which the UE computes its own position is described as "UE-based"
A measure of the trust in the accuracy of the position-related data and the ability to provide associated alerts.
Pre-configured assistance data:
Refers to the DL-PRS assistance data (with associated validity criteria) that can be provided to the UE (before or during an ongoing LPP positioning session), to be then utilized for potential positioning measurements at a future time (e.g. for deferred MT-LR). Pre-configured DL-PRS assistance data may consist of multiple instances, where each instance is applicable to a different area within the network.
Protection Level (PL):
A statistical upper-bound of the Positioning Error (PE) that ensures that, the probability per unit of time of the true error being greater than the AL and the PL being less than or equal to the AL, for longer than the TTA, is less than the required TIR, i.e., the PL satisfies the following inequality:
Prob per unit of time [((PE>AL) & (PL≤AL)) for longer than TTA] < required TIR
When the PL bounds the positioning error in the horizontal plane or on the vertical axis then it is called Horizontal Protection Level (HPL) or Vertical Protection Level (VPL) respectively.
A specific equation for the PL is not specified as this is implementation-defined. For the PL to be considered valid, it must simply satisfy the inequality above.
A TP which only transmits PRS, DL-PRS signals and is not associated with a cell.
PRS Processing Window (PPW):
The PRS Processing Window is configured by the network to a UE for NR DL-PRS measurements without measurement gap.
Reception Point (RP):
A set of geographically co-located receive antennas (e.g. antenna array (with one or more antenna elements)) for one cell, part of one cell or one UL-SRS-only RP. Reception Points can include base station (ng-eNB or gNB) antennas, remote radio heads, a remote antenna of a base station, an antenna of a UL-SRS-only RP, etc. One cell can include one or multiple reception points. For a homogeneous deployment, each reception point may correspond to one cell.
Rx Time Delay:
From a signal reception perspective, there will be a time delay from the time when the RF signal arrives at the Rx antenna to the time when the signal is digitized and time-stamped at the baseband.
Rx Timing Error:
Result of Rx time delay involved in the reception of a signal before reporting measurements that are obtained from the signal. It is the uncalibrated Rx time delay, or the remaining delay after the UE/TRP internal calibration/compensation of the Rx time delay, involved in the reception of the DL-PRS/UL SRS signals. The calibration/compensation may also include the calibration/compensation of the relative time delay between different RF chains in the same UE/TRP and may also possibly consider the offset of the Rx antenna phase centre to the physical antenna centre.
An RP which only receives UL-SRS signals and is not associated with a cell.
Transmission Point (TP):
A set of geographically co-located transmit antennas (e.g. antenna array (with one or more antenna elements)) for one cell, part of one cell or one DL-PRS-only TP. Transmission Points can include base station (ng-eNB or gNB) antennas, remote radio heads, a remote antenna of a base station, an antenna of a DL-PRS-only TP, etc. One cell can include one or multiple transmission points. For a homogeneous deployment, each transmission point may correspond to one cell.
Transmission-Reception Point (TRP):
A set of geographically co-located antennas (e.g. antenna array (with one or more antenna elements)) supporting TP and/or RP functionality.
TRP Rx 'Timing Error Group' (TRP Rx TEG):
Rx timing errors, associated with TRP reporting of one or more UL measurements, that are within a certain margin.
TRP RxTx 'Timing Error Group' (TRP RxTx TEG):
Rx timing errors and Tx timing errors, associated with TRP reporting of one or more gNB Rx-Tx time difference measurements, which have the 'Rx timing errors+Tx timing errors' differences within a certain margin.
TRP Tx 'Timing Error Troup' (TRP Tx TEG):
Tx timing errors, associated with TRP transmissions on one or more DL-PRS resources, that are within a certain margin.
Tx Time Delay:
From a signal transmission perspective, the time delay from the time when the digital signal is generated at baseband to the time when the RF signal is transmitted from the Tx antenna.
Tx Timing Error:
Result of Tx time delay involved in the transmission of a signal. It is the uncalibrated Tx time delay, or the remaining delay after the TRP/UE internal calibration/compensation of the Tx time delay, involved in the transmission of the DL-PRS/UL SRS signals. The calibration/compensation may also include the calibration/compensation of the relative time delay between different RF chains in the same TRP/UE and may also possibly consider the offset of the Tx antenna phase centre to the physical antenna centre.
UE Rx 'Timing Error Group' (UE Rx TEG):
Rx timing errors, associated with UE reporting of one or more DL measurements (RSTD), that are within a certain margin.
UE RxTx 'Timing Error Group' (UE RxTx TEG):
Rx timing errors and Tx timing errors, associated with UE reporting of one or more UE Rx-Tx time difference measurements, which have the 'Rx timing errors+Tx timing errors' differences within a certain margin.
UE Tx 'Timing Error Group' (UE Tx TEG):
Tx timing errors, associated with UE transmissions on one or more UL SRS resources for positioning purpose, that are within a certain margin.
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
5G Core Network
Azimuth-Angle of Arrival
Accumulated Delta Range
Angle of Arrival
Antenna Reference Point
BeiDou Navigation Satellite System
Basic Service Set Identifier
Cell-ID (positioning method)
Centimetre Level Augmentation Service
Downlink Positioning Reference Signal
Downlink Time Difference Of Arrival
Do Not Use
Enhanced Serving Mobile Location Centre
Enhanced Cell-ID (positioning method)
European Geostationary Navigation Overlay Service
Evolved Universal Terrestrial Radio Access Network
Frequency Division Multiple Access
Flächenkorrekturparameter (Engl: Area Correction Parameters)
GPS Aided Geo Augmented Navigation
GLObal'naya NAvigatsionnaya Sputnikovaya Sistema (Engl.: Global Navigation Satellite System)
Gateway Mobile Location Centre
Global Navigation Satellite System
Global Positioning System
Geodetic Reference System 1980
Homogeneous Extended Service Set Identifier
Location Management Function
LTE Positioning Protocol
Master Auxiliary Concept
Metropolitan Beacon System
Mobile Originated Location Request
Mobile Terminated Location Request
Multi-Round Trip Time
NAVigation with Indian Constellation
NG Control plane
NG Application Protocol
Network Induced Location Request
Network - Real-Time Kinematic
NR Positioning Protocol A
Observed Time Difference Of Arrival
Protocol Data Unit
Positioning System Information
Precise Point Positioning
Precise Point Positioning - Real-Time Kinematic
Positioning Reference Signal (for E-UTRA)
Positioning Reference Unit
Quasi-Zenith Satellite System
Radio Resource Management
Reference Signal Received Power
Reference Signal Received Path Power
Reference Signal Received Quality
Received Signal Strength Indicator
Reference Signal Time Difference
Space Based Augmentation System
Small Data Transmission
SUPL Enabled Terminal
System Information Block
SUPL Location Platform
Sounding Reference Signal
Synchronization Signal Block
Service Set Identifier
State Space Representation
Secure User Plane Location
Terrestrial Beacon System
Total Electron Content
Timing Error Group
Time To Alert
Tx Timing Error Group
Uplink Angle of Arrival
Uplink Relative Time of Arrival
Uplink Sounding Reference Signal
Uplink Time Difference of Arrival
User Range Accuracy
Wide Area Augmentation System
World Geodetic System 1984
Wireless Local Area Network
Zenith Angles of Arrival