8.6.2 Transport block size determination
36.2133GPPEvolved Universal Terrestrial Radio Access (E-UTRA)Physical layer proceduresRelease 17TS
For a non-BL/CE UE and for 
, the UE shall first determine the TBS index (
) using 
except if the transport block is disabled in DCI format 4/4A/4B as specified below. For a transport block that is not mapped to two-layer spatial multiplexing, the TBS is determined by the procedure in Clause 7.1.7.2.1. For a transport block that is mapped to two-layer spatial multiplexing, the TBS is determined by the procedure in Clause 7.1.7.2.2.
For, DCI format 7-0A/7-0B, the derived transport block size as described in clause 7.1.7.2.1 when the transport block is mapped to one spatial layer and the derived transport block size after TBS translation as described in clauses 7.1.7.2.2, 7.1.7.2.4, 7.1.7.2.5 when the transport block is mapped to more than one spatial layer is scaled by 
, then rounded to the closest valid transport block size
– in Table 7.1.7.2.1-1 when the transport block is mapped to one spatial layer,
– the union of Table 7.1.7.2.1-1 and Table 7.1.7.2.2-1 when the transport block is mapped to two spatial layers,
– the union of Table 7.1.7.2.1-1 and Table 7.1.7.2.4-1when the transport block is mapped to three spatial layers,
– the union of Table 7.1.7.2.1-1 and Table 7.1.7.2.5-1when the transport block is mapped to four spatial layers,
where
– 
is given by higher layer parameter tbs-scalingFactorSubslotSPS-UL-Repetitions for subslot-PUSCH if the UE is configured with higher layer parameter totalNumberPUSCH-SPS-STTI-UL-Repetitions when the PDCCH/SPDCCH CRC is scrambled by SPS C-RNTI.
– 
for slot-PUSCH except if the UE is configured with a higher layer parameter symPUSCH-UpPts-r14 and the TB is transmitted in UpPTS of the special subframe in frame structure type 2, for slot-PUSCH in special subframe configuration with up to 3 UpPTS SC-FDMA data symbols, for slot-PUSCH in special subframe configuration with more than 3 UpPTS SC-FDMA data symbols, 
for subslot-PUSCH with one data symbol in the subslot, and 
for subslot-PUSCH with two or three data symbols in the subslot.
If the scaled TBS is closest to two valid transport block sizes, it is rounded to the larger transport block size.
For subframe-PUSCH, the UE shall determine the TBS index (
) using
and Table 8.6.1-3, if the UE is configured with higher layer parameter enable256QAM, and if the PDCCH corresponding to the PUSCH transmission is located in UE specific search space with CRC scrambled by the C-RNTI, and
– if higher layer parameter tpc-SubframeSet is configured, higher layer parameter subframeSet1-DCI-Format0=TRUE, the associated DCI is of format 0/0A/0B, and the subframe of the PUSCH belongs to uplink power control subframe set 1, or,
– if higher layer parameter tpc-SubframeSet is configured, higher layer parameter subframeSet1-DCI-Format4=TRUE, the associated DCI is of format 4/4A/4B, and the subframe of the PUSCH belongs to uplink power control subframe set 1, or,
– if higher layer parameter tpc-SubframeSet is configured, higher layer parameter subframeSet2-DCI-Format0=TRUE, the associated DCI is of format 0/0A/0B, and the subframe of the PUSCH belongs to uplink power control subframe set 2, or,
– if higher layer parameter tpc-SubframeSet is configured, higher layer parameter subframeSet2-DCI-Format4=TRUE, the associated DCI is of format 4/4A/4B, and the subframe of the PUSCH belongs to uplink power control subframe set 2, or,
– if higher layer parameter tpc-SubframeSet is not configured, higher layer parameter dci-Format0=TRUE, and the associated DCI is of format 0/0A/0B, or,
– if higher layer parameter tpc-SubframeSet is not configured, higher layer parameter dci-Format4=TRUE, and the associated DCI is of format 4/4A/4B;
otherwise, the UE shall determine the TBS index (
) using
and Table 8.6.1-1.
For subslot/slot-PUSCH, the UE shall determine the TBS index (
) using
and Table 8.6.1-3, if the UE is configured with higher layer parameter Enable256QAMSTTI, and if the PDCCH/SPDCCH corresponding to the PUSCH transmission is located in UE specific search space with CRC scrambled by the C-RNTI, and
– if higher layer parameter tpc-SubframeSet is configured, higher layer parameter subframeSet1-256QAM-STTI=TRUE, the associated DCI is of format 7-0A/7-0B, and the subframe of the slot/subslot-PUSCH belongs to uplink power control subframe set 1, or,
– if higher layer parameter tpc-SubframeSet is configured, higher layer parameter subframeSet2-256QAM-STTI=TRUE, the associated DCI is of format 7-0A/7-0B, and the subframe of the slot/subslot-PUSCH belongs to uplink power control subframe set 2, or,
– if higher layer parameter tpc-SubframeSet is not configured, and the associated DCI is of format 7-0A/7-0B;
otherwise, the UE shall determine the TBS index (
) using
and Table 8.6.1-1.
If the UE is configured with higher layer parameter symPUSCH-UpPts-r14, ttiBundling=FALSE, and the transport block is transmitted in UpPTS of the special subframe in frame structure type 2, then
– for special subframe configuration with up to 3 UpPTS SC-FDMA data symbols:
– set the Table 7.1.7.2.1-1 column indicator to 
instead of 
– otherwise:
– set the Table 7.1.7.2.1-1 column indicator to 
instead of 
.
If the transport block is transmitted on an LAA SCell,
– If 
, then
– if the UE is transmitting a Partial PUSCH Mode 2, or if the UE is transmitting a Partial PUSCH Mode 3 ending at symbol #6
– set the Table 7.1.7.2.1-1 column indicator to 
instead of 
– if the UE is transmitting a Partial PUSCH Mode 3 ending at symbol #3
– set the Table 7.1.7.2.1-1 column indicator to 
instead of 
– If the UE is configured with Partial PUSCH Mode 2 or 3 on the LAA SCell and 
, the transport block size shall be determined from the latest PDCCH/EPDCCH with DCI format 0A/0B/4A/4B for the same transport block using 
.
For a non-BL/CE UE and for 
,
– if DCI format 0/0A/0B/7-0A/7-0B is used and 
and N =1 (determined by the procedure in Clause 8.0) or, if DCI format 4 is used and only 1 TB is enabled and for the enabled TB and the number of transmission layers is 1 or if DCI format 4A/4B is used and 
for both TBs and N =1 (determined by the procedure in Clause 8.0), and if
– the "CSI request" bit field is 1 bit and is set to trigger an aperiodic CSI report and 
or,
– the "CSI request" bit field is 2 bits and is triggering an aperiodic CSI report for one serving cell according to Table 7.2.1-1A, and , 
or,
– the "CSI request" bit field is 2 bits and is triggering aperiodic CSI report for more than one serving cell according to Table 7.2.1-1A and, 
or,
– the "CSI request" bit field is 2 bits and is triggering an aperiodic CSI report for one CSI process according to Table 7.2.1-1B and 
or,
– the "CSI request" bit field is 2 bits and is triggering an aperiodic CSI report for more than one CSI process according to Table 7.2.1-1B and, 
or,
– the "CSI request" bit field is 2 bits and is triggering an aperiodic CSI report for one CSI process or {CSI process, CSI subframe set}-pair according to Table 7.2.1-1C and 
or,
– the "CSI request" bit field is 2 bits and is triggering an aperiodic CSI report for more than one CSI process and/or {CSI process, CSI subframe set}-pair according to Table 7.2.1-1C and 
, or
– the "CSI request" bit field is 3 bits and is triggering an aperiodic CSI report for one CSI process according to Table 7.2.1-1D or Table 7.2.1-1E or Table 7.2.1-1F or Table 7.2.1-1G and 
, or
– the "CSI request" bit field is 3 bits and is triggering an aperiodic CSI report for 2 to 5 CSI processes according to Table 7.2.1-1D or Table 7.2.1-1E or Table 7.2.1-1F or Table 7.2.1-1G and 
, or
– the "CSI request" bit field is 3 bits and is triggering an aperiodic CSI report for more than 5 CSI processes according to Table 7.2.1-1D or Table 7.2.1-1E or Table 7.2.1-1F or Table 7.2.1-1G, or
– the "CSI request" bit field in DCI format 0A/0B/4A/4B/7-0A/7-0B is set to trigger an aperiodic CSI report, or
– the "CSI request" bit field is 4 bits and is triggering an aperiodic CSI report for one CSI process according to Table 7.2.1-1H or Table 7.2.1-1I and 
, or
– the "CSI request" bit field is 4 bits and is triggering an aperiodic CSI report for 2 to 5 CSI processes according to Table 7.2.1-1H or Table 7.2.1-1I and 
, or
– the "CSI request" bit field is 4 bits and is triggering an aperiodic CSI report for more than 5 CSI processes according to Table 7.2.1-1H or Table 7.2.1-1I, or
– the "CSI request" bit field is 5 bits and is triggering an aperiodic CSI report for one CSI process according to Table 7.2.1-1J or Table 7.2.1-1K and 
, or
– the "CSI request" bit field is 5 bits and is triggering an aperiodic CSI report for 2 to 5 CSI processes according to Table 7.2.1-1J or Table 7.2.1-1K and 
, or
– the "CSI request" bit field is 5 bits and is triggering an aperiodic CSI report for more than 5 CSI processes according to Table 7.2.1-1J or Table 7.2.1-1K, or
– the "CSI request" bit field in DCI is set to trigger an aperiodic CSI report and UE is configured with higher layer parameter advancedCodebookEnabled,
– the "CSI request" bit field in DCI is set to trigger an aperiodic CSI report and UE is configured with higher layer parameter FeCoMPCSIEnabled,
then there is no transport block for the UL-SCH and only the control information feedback for the current PUSCH reporting mode is transmitted by the UE.
– Otherwise, the transport block size shall be determined from the initial PDCCH/EPDCCH/SPDCCH for the same transport block using 
. If there is no initial PDCCH/EPDCCH/SPDCCH with an uplink DCI format for the same transport block using 
, the transport block size shall be determined from
– the most recent semi-persistent scheduling assignment PDCCH/EPDCCH/SPDCCH, when the initial PUSCH for the same transport block is semi-persistently scheduled, or,
– the random access response grant for the same transport block, when the PUSCH is initiated by the random access response grant.
In DCI format 4 a transport block is disabled if either the combination of 
and 
or the combination of 
and 
is signalled, otherwise the transport block is enabled.
In DCI formats 4A/4B a transport block is disabled if 
and otherwise the transport block is enabled.
If DCI format 4B is used and 
for both TBs, UE is not expected to receive the value of N >1 as determined by the procedure in Clause 8.0.
If DCI format 0B is used and 
, UE is not expected to receive the value of N >1 as determined by the procedure in Clause 8.0.
For a BL/CE UE configured with CEModeA and a PUSCH transmission not scheduled by the Random Access Response Grant,
– if the UE is configured with higher layer parameter ce-PUSCH-SubPRB-Config-r15,
– if the value of the ‘number of resource units’ field in the scheduling grant is set to ’01’, the TBS is determined according to the procedure in Clause 7.1.7.2.1 with 
and 
for 
,
– elseif the value of the ‘number of resource units’ field in the scheduling grant is set to ’10’, the TBS is determined according to the procedure in Clause 7.1.7.2.1 with 
and 
for 
,
– elseif the value of the ‘number of resource units’ field in the scheduling grant is set to ’11’, 
where 
is the TBS determined according to the procedure in Clause 7.1.7.2.1 with 
and 
for 
,
– elseif the UE is configured with higher layer parameter ce-pusch-nb-maxTbs-config with value ‘On‘, and if the MPDCCH corresponding to the PUSCH transmission is located in UE-specific search space, the UE shall first determine the TBS index (
) using
and Table 8.6.1-2A;
– otherwise, the UE shall first determine the TBS index (
) using
and Table 8.6.1-2.
For a BL/CE UE configured with CEModeA and a PUSCH transmission not scheduled by the Random Access Response Grant,
– if the UE is configured with higher layer parameter edt-Parameters-r15, and if the uplink scheduling grant corresponding to the PUSCH transmission indicates a retransmission as part of the contention based random access procedure with 
and the most recent PUSCH transmission including a transport block with EDT, the TBS is determined by the procedure in Clause 7.1.7.2.1, for 
and the transport block does not include EDT;
– elseif the UE is configured with higher layer parameter edt-Parameters-r15, and if the uplink scheduling grant corresponding to the PUSCH transmission indicates a retransmission of the same transport block including EDT as part of the contention based random access procedure with 
,
– if the UE is configured with higher layer parameter edt-SmallTBS-Enabled-r15, the repetition number for the transmission of Msg3 PUSCH is the smallest integer multiple of M that is equal to or larger than
where 
is the TBS corresponding to the PUSCH transmission scheduled by the Random Access Response Grant, and 
is the value of the higher layer parameter edt-TBS-r15. M = 4 if 
> 4, M = 1 otherwise.
– otherwise, the TBS is given by higher layer parameter edt-TBS-r15.
– elseif the UE is not configured with higher layer parameter ce-PUSCH-SubPRB-Config-r15, or if the UE is configured with higher layer parameter ce-PUSCH-SubPRB-Config-r15 and the value of the ‘number of resource units’ field in the scheduling grant is set to ’00’
– if the UE is configured with higher layer parameter ce-pusch-maxBandwidth-config with value 5MHz, the TBS is determined by the procedure in Clause 7.1.7.2.1, for 
– otherwise, the TBS is determined by the procedure in Clause 7.1.7.2.1.
For a BL/CE UE configured with CEModeA and a PUSCH transmission scheduled by the Random Access Response Grant,
– if the UE is configured with higher layer parameter edt-Parameters-r15, and the higher layers indicate EDT to the physical layer as defined in [8],
– if the UE is not configured with higher layer parameter edt-SmallTBS-Enabled-r15, the TBS is given by higher layer parameter edt-TBS-r15, the UE selects a TBS from the allowed TBS values in Table 8.6.2-1 otherwise.
– otherwise, the UE shall determine the TBS index by the procedure in Clause 6.2.
Table 8.6.2-1: EDT TBS for CEModeA with edt-SmallTBS-Enabled-r15 set to "true".
|
edt-TBS-r15 |
edt-SmallTBS-Subset-r15 |
Allowable TBS values |
|
408 |
not configured |
328, 408 |
|
504 |
not configured |
328, 408, 456, 504 |
|
504 |
enabled |
408, 504 |
|
600 |
not configured |
328, 408, 504, 600 |
|
600 |
enabled |
408, 600 |
|
712 |
not configured |
328, 456, 600, 712 |
|
712 |
enabled |
456, 712 |
|
808 |
not configured |
328, 504, 712, 808 |
|
808 |
enabled |
504, 808 |
|
936 |
not configured |
328, 504, 712, 936 |
|
936 |
enabled |
504, 936 |
|
1000 |
not configured |
328, 536, 776, 1000 |
|
1000 |
enabled |
536, 1000 |
For a BL/CE UE configured with CEModeB,
– if the UE is configured with higher layer parameter edt-Parameters-r15, and if the PUSCH transmission is scheduled by the Random Access Response Grant, and the higher layers indicate EDT to the physical layer as defined in [8],
– if the UE is not configured with higher layer parameter edt-SmallTBS-Enabled-r15, the TBS is given by higher layer parameter edt-TBS-r15, the UE selects a TBS from the allowed TBS values in Table 8.6.2-2 otherwise.
– elseif the UE is configured with higher layer parameter edt-Parameters-r15, and if the uplink scheduling grant corresponding to the PUSCH transmission indicates a retransmission as part of the contention based random access procedure with 
and the most recent PUSCH transmission including a transport block with EDT, the UE shall determine the TBS index (
) using 
and Table 8.6.1-2, and the TBS is determined by the procedure in Clause 7.1.7.2.1, for 
and the transport block does not include EDT
– elseif the UE is configured with higher layer parameter edt-Parameters-r15, and if the uplink scheduling grant corresponding to the PUSCH transmission indicates a retransmission of the same transport block including EDT as part of the contention based random access procedure with 
,
– if the UE is configured with higher layer parameter edt-SmallTBS-Enabled-r15, the repetition number for the transmission of Msg3 PUSCH is the smallest integer multiple of M that is equal to or larger than 
where 
is the TBS corresponding to the PUSCH transmission scheduled by the Random Access Response Grant, and 
is the value of the higher layer parameter edt-TBS-r15. M = 4 if 
> 4, M = 1 otherwise.
– otherwise, the TBS is given by higher layer parameter edt-TBS-r15.
– elseif the UE is configured with higher layer parameter ce-PUSCH-SubPRB-Config-r15, and the value of the ‘sub-PRB allocation flag’ field in the scheduling grant is set to ‘1’,
– if the value of the ‘number of resource units’ field in the scheduling grant is set to ‘0’, the TBS is determined according to the procedure in Clause 7.1.7.2.1 with 
and 
for 
,
– elseif the value of the ‘number of resource units’ field in the scheduling grant is set to ‘1’, the TBS is determined according to the procedure in Clause 7.1.7.2.1 with 
and 
for 
,
– otherwise, the UE shall determine the TBS index (
) using 
and Table 8.6.1-2, and the TBS is determined according to the procedure in Clause 7.1.7.2.1 for 
, and 
=6 when resource allocation field is ‘110’ or ‘111’ otherwise
= 3.
Table 8.6.2-2: EDT TBS for CEModeB with edt-SmallTBS-Enabled-r15 set to "true".
|
edt-TBS-r15 |
edt-SmallTBS-Subset-r15 |
Allowable TBS values |
|
408 |
not configured |
328, 408 |
|
456 |
not configured |
328, 408, 456 |
|
456 |
enabled |
408, 456 |
|
504 |
not configured |
328, 408, 456, 504 |
|
504 |
enabled |
408, 504 |
|
600 |
not configured |
328, 408, 504, 600 |
|
600 |
enabled |
408, 600 |
|
712 |
not configured |
328, 456, 600, 712 |
|
712 |
enabled |
456, 712 |
|
808 |
not configured |
328, 504, 712, 808 |
|
808 |
enabled |
504, 808 |
|
936 |
not configured |
328, 504, 712, 936 |
|
936 |
enabled |
504, 936 |