Secondary cell activation in new radio system
A method of activating a secondary cell (SCell) can include receiving on a primary cell (PCell) at a user equipment (UE) a first medium access control (MAC) control element (CE) for activating the SCell, receiving on the PCell a second MAC CE for indicating a first transmission configuration indication (TCI) state for receiving one of a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH) of the SCell, starting to perform a time-frequency tracking process in the SCell based on a synchronization signal block (SSB) indicated in the first TCI state without waiting for an arrival of a third MAC CE on the PCell for activating a semi-persistent (SP) channel state information reference signal (CSI-RS) resource set of the SCell, and performing a CSI reporting process based on the SP CSI-RS resource set activated by the third MAC CE on the SCell.
1. A method, comprising:
receiving on a primary cell (PCell) at a user equipment (UE) a first medium access control (MAC) control element (CE) for activating a secondary cell (SCell);
receiving on the PCell a second MAC CE for indicating a first transmission configuration indication (TCI) state for receiving one of a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH) of the SCell;
starting to perform a time-frequency tracking process in the SCell based on a synchronization signal block (SSB) indicated in the first TCI state without waiting for an arrival of a third MAC CE on the PCell for activating a semi-persistent (SP) channel state information reference signal (CSI-RS) resource set of the SCell;
performing a channel state information (CSI) reporting process based on the SP CSI-RS resource set activated by the third MAC CE on the SCell; and
transmitting a measurement report indicating reference signal received power (RSRP) measurements associated with SSBs of the SCell before receiving the first MAC CE for activating the SCell.
2. The method of claim 1 , wherein the first MAC CE for activating the SCell is received in slot n, and a CSI report of the CSI reporting process is transmitted no later than in slot
n
+
T
H
A
R
Q
+
T
activation
_
time
+
T
CSI
_
reporting
New
Radio
(
NR
)
slot
length
,
where:
T HARQ denotes a delay between a downlink data transmission associated with the first MAC CE and a corresponding hybrid automatic repeat request (HARQ) acknowledgement,
T CSI_reporting denotes a delay including an uncertainty period in acquiring a first available downlink CSI resource during the CSI reporting process, processing time for the CSI report, and an uncertainty period in acquiring a first available CSI reporting resource, and
T activation_time denotes an activation delay that is
T MAC_CE +max( T uncertainty_MAC +T FineTime +T SSB ,T uncertainty_SP ),
where,
T MAC_CE denotes a delay including MAC CE parsing and applying time,
T uncertainty_MAC denotes a period between a reception of the first MAC CE and a reception of a last one of the second MAC CE and a fourth MAC CE for indicating a TCI state for receiving the other one of the PDCCH and the PDSCH of the SCell,
T FineTime denotes a period between the UE completing processing of the last one of the second MAC CE and the fourth MAC CE, and a timing of the SSB indicated in the first TCI state,
T SSB denotes a period for processing a received signal of the SSB indicated in the first TCI state, and
T uncertainty_SP denotes a period between the reception of the first MAC CE and a reception of the third MAC CE.
3. The method of claim 2 , wherein T activation_time is
3 ms+max( T uncertainty_MAC +T FineTime +2 ms, T uncertainty_SP ).
4. The method of claim 1 , wherein the PCell is a primary cell of a primary cell group (PCG), or a primary cell of a secondary cell group (SCG).
5. An apparatus, comprising circuitry configured to:
receive on a primary cell (PCell) at a user equipment (UE) a first medium access control (MAC) control element (CE) for activating a secondary cell (SCell);
receive on the PCell a second MAC CE for indicating a first transmission configuration indication (TCI) state for receiving one of a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH) of the SCell;
start to perform a time-frequency tracking process in the SCell based on a synchronization signal block (SSB) indicated in the first TCI state without waiting for an arrival of a third MAC CE on the PCell for activating a semi-persistent (SP) channel state information reference signal (CSI-RS) resource set of the SCell;
perform a channel state information (CSI) reporting process based on the SP CSI-RS resource set activated by the third MAC CE on the SCell; and
transmit a measurement report indicating reference signal received power (RSRP) measurements associated with SSBs of the SCell before receiving the first MAC CE for activating the SCell.
6. The apparatus of claim 5 , wherein the first MAC CE for activating the SCell is received in slot n, and a CSI report of the CSI reporting process is transmitted no later than in slot
n
+
T
H
A
R
Q
+
T
activation
_
time
+
T
CSI
_
reporting
New
Radio
(
NR
)
slot
length
,
where:
T HARQ denotes a delay between a downlink data transmission associated with the first MAC CE and a corresponding hybrid automatic repeat request (HARQ) acknowledgement,
T CSI_reporting denotes a delay including an uncertainty period in acquiring a first available downlink CSI resource during the CSI reporting process, processing time for the CSI report, and an uncertainty period in acquiring a first available CSI reporting resource, and
T activation_time denotes an activation delay that is
T MAC_CE +max( T uncertainty_MAC +T FineTime +T SSB ,T uncertainty_SP ),
where,
T MAC_CE denotes a delay including MAC CE parsing and applying time,
T uncertainty_MAC denotes a period between a reception of the first MAC CE and a reception of a last one of the second MAC CE and a fourth MAC CE for indicating a TCI state for receiving the other one of the PDCCH and the PDSCH of the SCell,
T FineTime denotes a period between the UE completing processing of the last one of the second MAC CE and the fourth MAC CE, and a timing of the SSB indicated in the first TCI state,
T SSB denotes a period for processing a received signal of the SSB indicated in the first TCI state, and
T uncertainty_SP denotes a period between the reception of the first MAC CE and a reception of the third MAC CE.
7. The apparatus of claim 6 , wherein T activation_time is
3 ms+max( T uncertainty_MAC +T FineTime +2 ms, T uncertainty_SP ).
8. The apparatus of claim 5 , wherein the PCell is a primary cell of a primary cell group (PCG), or a primary cell of a secondary cell group (SCG).
9. A method, comprising:
receiving on a primary cell (PCell) at a user equipment (UE) a first medium access control (MAC) control element (CE) for activating a secondary cell (SCell);
receiving on the PCell a second MAC CE for indicating a first transmission configuration indication (TCI) state for receiving one of a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH) of the SCell;
starting to perform a time-frequency tracking process in the SCell based on a synchronization signal block (SSB) indicated in the first TCI state without waiting for an arrival of a third MAC CE on the PCell for activating a semi-persistent (SP) channel state information reference signal (CSI-RS) resource set of the SCell;
performing a channel state information (CSI) reporting process based on the SP CSI-RS resource set activated by the third MAC CE on the SCell; and
transmitting an RSRP measurement report indicating reference signal received power (RSRP) measurements associated with SSBs of the SCell after receiving the first MAC CE for activating the SCell.
10. The method of claim 9 , wherein the first MAC CE for activating the SCell is received in slot n, and a CSI report of the CSI reporting process is transmitted no later than in slot
n
+
T
H
A
R
Q
+
T
activation
_
time
+
T
CSI
_
reporting
New
Radio
(
NR
)
slot
length
,
where:
T HARQ denotes a delay between a downlink data transmission associated and a corresponding hybrid automatic repeat request (HARQ) acknowledgement,
T CSI_reporting denotes a delay including an uncertainty period in acquiring a first available downlink CSI resource during the CSI reporting process, processing time for the CSI report, and an uncertainty period in acquiring a first available CSI reporting resource, and
T activation_time is an activation delay that is
2* T MAC_CE +T cell identification with Rx training +T L1-RSRP, measure +T L1-RSRP, report +T HARQ +max( T uncertainty_MAC +T FineTiming +T SSB ,T uncertainty_SP ),
where,
T cell identification with Rx training is the time for cell identification with Rx beam training,
T L1-RSRP, measure is an L1-RSRP measurement time associated with the RSRP measurement report,
T L1-RSRP, report is a delay of CSI reporting for the RSRP measurement report,
T MAC_CE denotes a delay including MAC CE parsing and applying time,
T uncertainty_MAC denotes a period between a transmission of the RSRP measurement report and a reception of a last one of the second MAC CE and a fourth MAC CE for indicating a TCI state for receiving the other one of the PDCCH and the PDSCH of the SCell,
T FineTime denotes a period between the UE completing processing of the last one of the second MAC CE and the fourth MAC CE, and a timing of the SSB indicated in the first TCI state,
T SSB denotes a period for processing a received signal of the SSB indicated in the first TCI state, and
T uncertainty_SP denotes a period between a transmission of the RSRP measurement report and a reception of the third MAC CE.
11. The method of claim 10 , wherein T activation_time is
6 ms+ T cell identification with Rx training +T L1-RSRP, measure +T L1-RSRP, report +T HARQ +max( T uncertainty_MAC +T FineTiming +2 ms, T uncertainty_SP ).
12. An apparatus, comprising circuitry configured to:
receive on a primary cell (PCell) at a user equipment (UE) a first medium access control (MAC) control element (CE) for activating a secondary cell (SCell);
receive on the PCell a second MAC CE for indicating a first transmission configuration indication (TCI) state for receiving one of a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH) of the SCell;
start to perform a time-frequency tracking process in the SCell based on a synchronization signal block (SSB) indicated in the first TCI state without waiting for an arrival of a third MAC CE on the PCell for activating a semi-persistent (SP) channel state information reference signal (CSI-RS) resource set of the SCell;
perform a channel state information (CSI) reporting process based on the SP CSI-RS resource set activated by the third MAC CE on the SCell; and
transmit an RSRP measurement report indicating reference signal received power (RSRP) measurements associated with SSBs of the SCell after receiving the first MAC CE for activating the SCell.
13. The apparatus of claim 12 , wherein the first MAC CE for activating the SCell is received in slot n, and a CSI report of the CSI reporting process is transmitted no later than in slot
n
+
T
H
A
R
Q
+
T
activation
_
time
+
T
CSI
_
reporting
New
Radio
(
NR
)
slot
length
,
where:
T HARQ denotes a delay between a downlink data transmission associated and a corresponding hybrid automatic repeat request (HARQ) acknowledgement,
T CSI_reporting denotes a delay including an uncertainty period in acquiring a first available downlink CSI resource during the CSI reporting process, processing time for the CSI report, and an uncertainty period in acquiring a first available CSI reporting resource, and
T activation_time is an activation delay that is
2* T MAC_CE +T cell identification with Rx training +T L1-RSRP, measure +T L1-RSRP, report +T HARQ +max( T uncertainty_MAC +T FineTiming +T SSB ,T uncertainty_SP ),
where,
T cell identification with Rx training is the time for cell identification with Rx beam training,
T L1-RSRP, measure is an L1-RSRP measurement delay associated with the RSRP measurement report,
T L1-RSRP, report is a delay of CSI reporting for the RSRP measurement report,
T MAC_CE denotes a delay including MAC CE parsing and applying time,
T uncertainty_MAC denotes a period between a transmission of the RSRP measurement report and a reception of a last one of the second MAC CE and a fourth MAC CE for indicating a TCI state for receiving the other one of the PDCCH and the PDSCH of the SCell,
T FineTime denotes a period between the UE completing processing of the last one of the second MAC CE and the fourth MAC CE, and a timing of the SSB indicated in the first TCI state,
T SSB denotes a period for processing a received signal of the SSB indicated in the first TCI state, and
T uncertainty_SP denotes a period between a transmission of the RSRP measurement report and a reception of the third MAC CE.
14. The apparatus of claim 13 , wherein T activation_time is
6 ms+ T cell identification with Rx training +T L1-RSRP, measure +T L1-RSRP, report +T HARQ +max( T uncertainty_MAC +T FineTiming +2 ms, T uncertainty_SP ).