7 Physical downlink shared channel related procedures
36.2133GPPEvolved Universal Terrestrial Radio Access (E-UTRA)Physical layer proceduresRelease 17TS
If the UE is configured with a SCG, the UE shall apply the procedures described in this clause for both MCG and SCG unless stated otherwise
– When the procedures are applied for MCG, the terms ‘secondary cell’, ‘secondary cells’, ‘serving cell’, and ‘serving cells’ in this clause refer to secondary cell, secondary cells, serving cell or serving cells belonging to the MCG respectively unless stated otherwise. The terms ‘subframe’ and ‘subframes’ refer to subframe or subframes belonging to MCG.
– When the procedures are applied for SCG, the terms ‘secondary cell’, ‘secondary cells’, ‘serving cell’ and ‘serving cells’ in this clause refer to secondary cell, secondary cells (not including the PSCell), serving cell, serving cells belonging to the SCG respectively unless stated otherwise. The term ‘primary cell’ in this clause refers to the PSCell of the SCG. The terms ‘subframe’ and ‘subframes’ refer to subframe or subframes belonging to SCG
If a UE is configured with dl-TTI-Length, and PDSCH is received in a slot, the term ‘slot/subslot’ refers to a slot in this clause.
If the UE is configured with dl-TTI-Length, and PDSCH is received in a subslot, the term ‘slot/subslot’ refers to a subslot in this clause.
If a UE is configured with a LAA Scell, the UE shall apply the procedures described in this clause assuming frame structure type 1 for the LAA Scell unless stated otherwise.
For FDD,
– if the UE supports ce-pdsch-tenProcesses and is configured with CEModeA and higher layer parameter ce-pdsch-tenProcesses-config set to ‘On‘ there shall be a maximum of 10 downlink HARQ processes per serving cell;
– if the BL/CE UE is configured with higher layer parameter ce-PDSCH-14HARQ-Config, and configured with CEModeA, there shall be a maximum of 14 downlink HARQ processes per serving cell.
– 16 downlink HARQ processes per serving cell configured with higher layer parameter dl-TTI-Length
– otherwise, there shall be a maximum of 8 downlink HARQ processes per serving cell.
For FDD-TDD and primary cell frame structure type 1, there shall be a maximum of
– 16 downlink HARQ processes per serving cell configured with higher layer parameter dl-TTI-Length
– 8 downlink HARQ processes per serving cell, otherwise.
For TDD and a UE not configured with the parameter EIMTA-MainConfigServCell-r12 for any serving cell,, if the UE is configured with one serving cell, or if the UE is configured with more than one serving cell and the TDD UL/DL configuration of all the configured serving cells is the same, the maximum number of downlink HARQ processes per serving cell configured with higher layer parameter dl-TTI-Length shall be 16, otherwise determined by the UL/DL configuration (Table 4.2-2 of [3]), as indicated in Table 7-1.
For TDD, if a UE is configured with more than one serving cell and if the TDD UL/DL configuration of at least two configured serving cells is not the same, or if the UE is configured with the parameter EIMTA-MainConfigServCell-r12 for at least one serving cell, or for FDD-TDD and primary cell frame structure type 2 and serving cell frame structure type 2, the maximum number of downlink HARQ processes for a serving cell configured with higher layer parameter dl-TTI-Length shall be 16, otherwise determined as indicated in Table 7-1, wherein the "TDD UL/DL configuration" in Table 7-1 refers to the DL-reference UL/DL configuration for the serving cell (as defined in Clause 10.2).
For FDD-TDD and primary cell frame structure type 2 and serving cell frame structure type 1, the maximum number of downlink HARQ processes for the serving cell configured with higher layer parameter dl-TTI-Length shall be 16, otherwise determined by the DL-reference UL/DL configuration for the serving cell (as defined in Clause 10.2), as indicated in Table 7-2.
A BL/CE UE configured with CEModeB is not expected to support more than 4 downlink HARQ processes if the UE is configured with higher layer parameter ce-PDSCH-MultiTB-Config, 2 downlink HARQ processes otherwise.
For TDD and a BL/CE configured with CEModeA, the maximum number of downlink HARQ processes for a serving cell shall be determined as indicated in Table 7-3.
For a UE configured with EN-DC/NE-DC, if serving cell frame structure type 1 and if the UE is configured with tdm-PatternConfig/tdm-PatternConfigNE-DC for the serving cell, or if the UE is configured with tdm-PatternConfig2 for a serving cell with EN-DC, the maximum number of downlink HARQ processes for the serving cell shall be determined by DL-reference UL/DL configuration given by tdm-PatternConfig/tdm-PatternConfigNE-DC/tdm-PatternConfig2 for the serving cell, as indicated in Table 7-2.
For a UE configured with EN-DC/NE-DC and more than one serving cells, if primary cell frame structure type 1 and if the UE is configured with tdm-PatternConfig/tdm-PatternConfigNE-DC for the primary cell, or if the UE is configured with tdm-PatternConfig2 for a primary cell with EN-DC, the maximum number of downlink HARQ processes for each secondary cell is equal to the maximum number of downlink HARQ processes for the primary cell.
The dedicated broadcast HARQ process defined in [8] is not counted as part of the maximum number of HARQ processes for FDD, TDD and FDD-TDD.
Table 7-1: Maximum number of DL HARQ processes for TDD
|
TDD UL/DL configuration |
Maximum number of HARQ processes |
|
0 |
4 |
|
1 |
7 |
|
2 |
10 |
|
3 |
9 |
|
4 |
12 |
|
5 |
15 |
|
6 |
6 |
Table 7-2: Maximum number of DL HARQ processes for FDD-TDD, primary cell frame structure type 2, and serving cell frame structure type 1
|
DL-reference UL/DL Configuration |
Maximum number of HARQ processes |
|
0 |
10 |
|
1 |
11 |
|
2 |
12 |
|
3 |
15 |
|
4 |
16 |
|
5 |
16 |
|
6 |
12 |
Table 7-3: Maximum number of DL HARQ processes for TDD
(UE configured with CEModeA)
|
TDD UL/DL configuration |
Maximum number of HARQ processes |
|
0 |
6 |
|
1 |
9 |
|
2 |
12 |
|
3 |
11 |
|
4 |
14 |
|
5 |
16 |
|
6 |
8 |