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.
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.
Active Time:
Time related to DRX operation, as defined in clause 5.7, during which the MAC entity monitors the PDCCH.
mac-ContentionResolutionTimer:
Specifies the number of consecutive subframe(s) during which the MAC entity shall monitor the PDCCH after Msg3 is transmitted.
DRX Cycle:
Specifies the periodic repetition of the On Duration followed by a possible period of inactivity (see Figure 3.1-1 below).
Except for NB-IoT UEs, BL UEs or UEs in enhanced coverage, it specifies the number of consecutive PDCCH-subframe(s) after the subframe in which a PDCCH indicates an initial UL, DL or SL user data transmission for this MAC entity. For NB-IoT UEs, it specifies the number of consecutive PDCCH-subframe(s), after the subframe in which the HARQ RTT timer or UL HARQ RTT timer expires, or after PDCCH indicates a new UL or DL transmission for one TB when the UE is configured with multiple HARQ processes. For BL UEs or UEs in enhanced coverage, it specifies the number of consecutive PDCCH-subframe(s) following the subframe containing the last repetition of the PDCCH reception that indicates an initial UL or DL user data transmission for this MAC entity.
drx-RetransmissionTimer:
Specifies the maximum number of consecutive PDCCH-subframe(s) until a DL retransmission is received.
drx-RetransmissionTimerShortTTI:
Specifies the maximum number of consecutive TTI(s) until a DL retransmission is received for HARQ processes scheduled using short TTI.
drxShortCycleTimer:
Specifies the number of consecutive subframe(s) the MAC entity shall follow the Short DRX cycle.
drxStartOffset:
Specifies the subframe where the DRX Cycle starts.
drx-ULRetransmissionTimer:
Specifies the maximum number of consecutive PDCCH-subframe(s) until a grant for UL retransmission or the HARQ feedback is received.
drx-ULRetransmissionTimeShortTTI:
Specifies the maximum number of consecutive TTI(s) until a grant for UL retransmission is received for HARQ processes scheduled using short TTI.
Early Data Transmission:
Allows one uplink data transmission optionally followed by one downlink data transmission during the random access procedure as specified in TS 36.300. The S1 connection is established or resumed upon reception of the uplink data and may be released or suspended along with the transmission of the downlink data. Early data transmission refers to both CP-EDT and UP-EDT.
HARQ information:
HARQ information for DL-SCH or for UL-SCH transmissions consists of New Data Indicator (NDI), Transport Block (TB) size. For DL-SCH transmissions and for asynchronous UL HARQ and for autonomous UL HARQ, the HARQ information also includes HARQ process ID, except for UEs in NB-IoT configured with a single HARQ process for which this information is not present. For UL-SCH transmission the HARQ information also includes Redundancy Version (RV). In case of spatial multiplexing on DL-SCH the HARQ information comprises a set of NDI and TB size for each transport block. HARQ information for SL-SCH and SL-DCH transmissions consists of TB size only.
HARQ RTT Timer:
This parameter specifies the minimum amount of subframe(s) before a DL assignment for HARQ retransmission is expected by the MAC entity.
Msg3:
Message transmitted on UL-SCH containing a C-RNTI MAC CE or a CCCH SDU optionally multiplexed with DTCH for the UP-EDT, submitted from upper layer and associated with the UE Contention Resolution Identity, as part of a random access procedure.
NB-IoT:
NB-IoT allows access to network services via E-UTRA with a channel bandwidth limited to 200 kHz.
NB-IoT UE:
A UE that uses NB-IoT.
NR sidelink communication:
AS functionality enabling at least V2X Communication as defined in TS 23.287, between two or more nearby UEs, using NR technology but not traversing any network node.
Non-terrestrial networks:
An E-UTRAN consisting of eNBs, which provide non-terrestrial LTE access to UEs by means of an NTN payload embarked on a space-borne NTN vehicle and an NTN Gateway.
onDurationTimer:
Specifies the number of consecutive PDCCH-subframe(s) at the beginning of a DRX Cycle.
PDCCH:
Refers to the PDCCH (see TS 36.211), EPDCCH (in subframes when configured), MPDCCH (see TS 36.213), for an RN with R-PDCCH configured and not suspended, to the R-PDCCH, for NB-IoT to the NPDCCH or for short TTI to SPDCCH.
PDCCH period (pp):
Refers to the interval between the start of two consecutive PDCCH occasions and depends on the currently used PDCCH search space, as specified in TS 36.213. A PDCCH occasion is the start of a search space and is defined by subframe k0 as specified in clause 16.6 of TS 36.213. The calculation of number of PDCCH-subframes for the timer configured in units of a PDCCH period is done by multiplying the number of PDCCH periods with npdcch-NumRepetitions-RA when the UE uses the common search space or by npdcch-NumRepetitions when the UE uses the UE specific search space. When counting a timer whose length is calculated in PDCCH-subframes, the UE shall include PDCCH-subframes that will be dropped or not required to be monitored as specified in clause 16.6 of TS 36.213. The calculation of number of subframes for the timer configured in units of a PDCCH period is done by multiplying the number of PDCCH periods with duration between two consecutive PDCCH occasions.
PDCCH-subframe:
Refers to a subframe with PDCCH. This represents the union over PDCCH-subframes for all serving cells excluding cells configured with cross carrier scheduling for both uplink and downlink, as specified in TS 36.331; except if the UE is not capable of simultaneous reception and transmission in the aggregated cells where this instead represents the PDCCH-subframes of the SpCell.
For FDD serving cells, all subframes represent PDCCH-subframes, unless specified otherwise in this clause.
For TDD serving cells, all downlink subframes and subframes including DwPTS of the TDD UL/DL configuration indicated by tdd-Config, as specified in TS 36.331 of the cell represent PDCCH-subframes, unless specified otherwise in this clause.
For serving cells operating according to Frame structure Type 3, all subframes represent PDCCH-subframes.
For RNs with an RN subframe configuration configured and not suspended, in its communication with the E-UTRAN, all downlink subframes configured for RN communication with the E-UTRAN represent PDCCH-subframes.
For SC-PTM reception on an FDD cell, all subframes except MBSFN subframes represent PDCCH-subframes, unless specified otherwise in this clause.
For SC-PTM reception on a TDD cell, all downlink subframes and subframes including DwPTS of the TDD UL/DL configuration indicated by tdd-Config, as specified in TS 36.331 of the cell except MBSFN subframes represent PDCCH-subframes, unless specified otherwise in this clause.
For BL UE or UE in enhanced coverage, all subframes in which the UE is required to monitor MPDCCH represent PDCCH-subframes among all valid subframes regardless of whether the subframe is dropped, see clause 9.1.5 of TS 36.213.
For NB-IoT UE, all subframes that are part of the NPDCCH search space represent PDCCH-subframes among all NB-IoT downlink subframes, including those which the UE is not required to monitor as specified in clause 16.6 of TS 36.213.
PDSCH:
Refers to subframe-PDSCH/slot-PDSCH/subslot-PDSCH or for NB-IoT to NPDSCH.
PRACH:
Refers to PRACH or for NB-IoT to NPRACH.
PRACH Resource Index:
The index of a PRACH within a system frame, see TS 36.211
Primary Timing Advance Group:
Timing Advance Group containing the SpCell.
PUCCH SCell:
An SCell configured with PUCCH/SPUCCH.
PUSCH:
Refers to subframe-PUSCH/slot-PUSCH/subslot-PUSCH or for NB-IoT to NPUSCH.
ra-PRACH-MaskIndex:
Defines in which PRACHs within a system frame the MAC entity can transmit a Random Access Preamble (see clause 7.3).
RA-RNTI:
The Random Access RNTI is used on the PDCCH when Random Access Response messages are transmitted. It unambiguously identifies which time-frequency resource was utilized by the MAC entity to transmit the Random Access preamble.
SC Period:
Sidelink Control period, the time period consisting of transmission of SCI and its corresponding data.
SCI:
The Sidelink Control Information contains the sidelink scheduling information such as resource block assignment, modulation and coding scheme, Group Destination ID (for sidelink communication) and PPPP (for V2X sidelink communication), see TS 36.212.
Secondary Timing Advance Group:
Timing Advance Group not containing the SpCell. A Secondary Timing Advance Group contains at least one Serving Cell with an UL configured.
For 1 ms TTI length, the operation with short processing time in UL data transmission and DL data reception.
Short TTI:
TTI length based on a slot or a subslot.
Sidelink:
UE to UE interface for sidelink communication, sidelink discovery and V2X sidelink communication. The sidelink corresponds to the PC5 interface as defined in TS 23.303 for sidelink communication and sidelink discovery, and as defined in TS 23.285 for V2X sidelink communication.
Sidelink communication:
AS functionality enabling ProSe Direct Communication as defined in TS 23.303, between two or more nearby UEs, using E-UTRA technology but not traversing any network node.
Sidelink Discovery Gap for Reception:
Time period during which the UE does not receive any channels in DL from any serving cell, except during random access procedure.
Sidelink Discovery Gap for Transmission:
Time period during which the UE prioritizes transmission of sidelink discovery and associated procedures e.g. re-tuning and synchronisation over transmission of channels in UL, if they occur in the same subframe, except during random access procedure.
Special Cell:
For Dual Connectivity operation the term Special Cell refers to the PCell of the MCG or the PSCell of the SCG, otherwise the term Special Cell refers to the PCell.
Timing Advance Group:
A group of Serving Cells that is configured by RRC and that, for the cells with an UL configured, using the same timing reference cell and the same Timing Advance value.
Transmission using PUR:
Allows one uplink data transmission using preconfigured uplink resource from RRC_IDLE mode as specified in TS 36.300. Transmission using PUR refers to both CP transmission using PUR and UP transmission using PUR.
UE-eNB RTT:
For non-terrestrial networks, the sum of the UE's Timing Advance value (see clause 8.1 of TS 36.211) and k-Mac in units of subframe, not rounded or truncated toward an integer number of subframes.
UL HARQ RTT Timer:
This parameter specifies the minimum amount of subframe(s) before a UL HARQ retransmission grant is expected by the MAC entity.
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.
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.
AS
Access Stratum
AUL
Autonomous Uplink
BL
Bandwidth reduced Low complexity
BR
Bandwidth Reduced
BSR
Buffer Status Report
C-RNTI
Cell RNTI
CBR
Channel Busy Ratio
CC-RNTI
Common Control RNTI
CG
Cell Group
CQI
Channel Quality Indicator
CRI
CSI-RS Resource Indicator
CSI
Channel State Information
DAPS
Dual Active Protocol Stack
DCQR
Downlink Channel Quality Report
DRB
Data Radio Bearer
EDT
Early Data Transmission
eIMTA
Enhanced Interference Management and Traffic Adaptation
eIMTA-RNTI
Enhanced Interference Management and Traffic Adaptation - RNTI
E-UTRA
Evolved UMTS Terrestrial Radio Access
E-UTRAN
Evolved UMTS Terrestrial Radio Access Network
G-RNTI
Group RNTI
H-SFN
Hyper SFN
MAC
Medium Access Control
MCG
Master Cell Group
M-RNTI
MBMS RNTI
MPDCCH
MTC Physical Downlink Control Channel
LCG
Logical Channel Group
NB-IoT
Narrow Band Internet of Things
NPDCCH
Narrowband Physical Downlink Control Channel
NPDSCH
Narrowband Physical Downlink Shared channel
NPRACH
Narrowband Physical Random Access Control Channel
NPUSCH
Narrowband Physical Uplink Shared channel
PCell
Primary Cell
PSCell
Primary Secondary Cell
PHR
Power Headroom Report
PMI
Precoding Matrix Index
PPPP
ProSe Per-Packet Priority
P-RNTI
Paging RNTI
ProSe
Proximity-based Services
pTAG
Primary Timing Advance Group
PTI
Precoding Type Indicator
PUR
Preconfigured Uplink Resource
RA-RNTI
Random Access RNTI
RAI
Release Assistance Indication
RI
Rank Indicator
RN
Relay Node
RNTI
Radio Network Temporary Identifier
SCell
Secondary Cell
SC-FDM
Single-Carrier Frequency Division Multiplexing
SCG
Secondary Cell Group
SCI
Sidelink Control Information
SC-N-RNTI
Single Cell Notification RNTI
SC-PTM
Single Cell Point to Multipoint
SC-RNTI
Single Cell RNTI
SI-RNTI
System Information RNTI
SL
Sidelink
SL-RNTI
Sidelink RNTI
SL-V-RNTI
Sidelink V2X RNTI
SR
Scheduling Request
SRS
Sounding Reference Symbols
SRS-TPC-RNTI
Sounding Reference Symbols-Transmit Power Control-RNTI
SpCell
Special Cell
sTAG
Secondary Timing Advance Group
sTTI
Slot or subslot TTI
TAG
Timing Advance Group
TB
Transport Block
TPC-PUCCH-RNTI
Transmit Power Control-Physical Uplink Control Channel-RNTI
TPC-PUSCH-RNTI
Transmit Power Control-Physical Uplink Shared Channel-RNTI