Secondary cell activation in new radio system
A method of activating multiple secondary cells can include receiving on a primary cell (PCell) at a user equipment (UE) a first medium access (MAC) control element (CE) for activating a first secondary cell (SCell) and a second SCell for the UE in a wireless communication system. The first and second SCells can operate in a same band. No active serving cell operates on the same band for the UE. In response to that the first SCell is a known SCell, the second SCell is an unknown SCell, and both the first and second SCells operate in the same band that is a frequency range 2 (FR2) band, the first and second SCells can be activated in parallel without performing cell search and reference signal received power (RSRP) measurement and reporting over the first and second SCells.
1. A method, comprising:
receiving on a primary cell (PCell) at a user equipment (UE) a first medium access (MAC) control element (CE) for activating a first secondary cell (SCell) and a second SCell for the UE from a base station in a wireless communication system, the first and second SCells operating in a same band, no active serving cell operating on the same band for the UE; and
activating the first and second SCells in parallel without performing cell search and reference signal received power (RSRP) measurement and reporting over the first and second SCells, in response to having the first SCell as a known SCell, the second SCell as an unknown SCell, and both the first and second SCells operating in the same band that is a frequency range 2 (FR2) band, wherein
the first SCell is the known SCell when the UE has transmitted an RSRP measurement report of the first SCell to the base station, and an interval between sending the RSRP measurement report and the receiving of the first MAC CE is shorter than a predefined time,
the activating the first and second SCells in parallel includes:
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 second SCell;
performing a time-frequency tracking process on the second SCell based on an SSB indicated in the first TCI state; and
in response to receiving a third MAC CE on the PCell for activating a semi-persistent (SP) channel state information reference signal (CSI-RS) resource set of the second 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 second SCell, and
the first MAC CE for activating the first and second SCells is received in slot n, and a CSI report of the CSI reporting process based on the SP CSI-RS resource set activated by the third MAC CE on the second SCell is transmitted no later than in slot
n
+
T
HARQ
+
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, wherein the fourth MAC CE indicates a second TCI state for receiving another one of the PDCCH and the PDSCH of the second 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.
2. The method of claim 1 , wherein T actiation_time is 3 ms+max(T uncertainty_MAC +T FineTime +2 ms, T uncertainty_SP ).
3. The method of claim 1 , wherein the activating the first and second SCells in parallel includes:
in response to receiving on the PCell a radio resource control (RRC) message for configuring periodic CSI-RS of the second SCell, performing a CSI reporting process based on the periodic SP CSI-RS configured by the RRC message on the second SCell.
4. The method of claim 3 , wherein the first MAC CE for activating the SCell is received in slot n, and a CSI report of the CSI reporting process based on the periodic SP CSI-RS of the second SCell is transmitted no later than in slot
n
+
T
HARQ
+
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 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
max( T MAC_CE +T uncertainty_MAC +T FineTime +T SSB ,T uncertainty_RRC +T RRC_delay −T HARQ ),
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, wherein the fourth MAC CE indicates a second TCI state for receiving another one of the PDCCH and the PDSCH of the second 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,
T uncertainty_RRC denotes a period between the reception of the first MAC CE and a reception of the RRC message, and
T RRC_delay denotes a period for processing the RRC message.
5. The method of claim 4 , wherein T activation_time is
max( T uncertainty_MAC +5 ms+ T FineTime ,T uncertainty_RRC +T RRC_delay −T HARQ ).
6. The method of claim 1 , further comprising:
in response to that both the first and second SCells are unknown SCells and operate in the same band that is an FR2 band,
performing a cell search on the first SCell;
transmitting an RSRP measurement report indicating RSRP measurements associated with an SSB of the first SCell; and
activating the second SCell without performing cell search and RSRP measurement and reporting over the second SCell.
7. The method of claim 1 , further comprising:
in response to that the first SCell is a known SCell, the second SCell is an unknown SCell, and both the first and second SCells operate in the same band that is a frequency range 1 (FR1) band, activating the first and second SCells in parallel without performing automatic gain control (AGC) gain settling and cell search over the first and second SCells.
8. 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).
9. An apparatus, comprising circuitry configured to:
receive on a primary cell (PCell) at a user equipment (UE) a first medium access (MAC) control element (CE) for activating a first secondary cell (SCell) and a second SCell for the UE from a base station in a wireless communication system, the first and second SCells operating in a same band, no active serving cell operating on the same band for the UE; and
activate the first and second SCells in parallel without performing cell search and reference signal received power (RSRP) measurement and reporting over the first and second SCells, in response to having the first SCell as a known SCell, the second SCell as an unknown SCell, and both the first and second SCells operating in the same band that is a frequency range 2 (FR2) band, wherein
the first SCell is the known SCell when the UE has transmitted an RSRP measurement report of the first SCell to the base station, and an interval between sending the RSRP measurement report and the receiving of the first MAC CE is shorter than a predefined time,
the activating the first and second SCells in parallel includes:
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 second SCell;
performing a time-frequency tracking process on the second SCell based on an SSB indicated in the first TCI state; and
in response to receiving a third MAC CE on the PCell for activating a semi-persistent (SP) channel state information reference signal (CSI-RS) resource set of the second 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 second SCell, and
the first MAC CE for activating the first and second SCells is received in slot n, and a CSI report of the CSI reporting process based on the SP CSI-RS resource set activated by the third MAC CE on the second SCell is transmitted no later than in slot
n
+
T
HARQ
+
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, wherein the fourth MAC CE indicates a second TCI state for receiving another one of the PDCCH and the PDSCH of the second 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.
10. The apparatus of claim 9 , wherein T activation_time is
3 ms+max( T uncertainty_MAC +T FineTime +2 ms ,T uncertainty_SP ).
11. The apparatus of claim 9 , wherein the circuitry is further configured to:
in response to receiving on the PCell a radio resource control (RRC) message for configuring periodic CSI-RS of the second SCell, perform a channel state information (CSI) reporting process based on the periodic SP CSI-RS configured by the RRC message on the second SCell.
12. The apparatus of claim 11 , wherein the first MAC CE for activating the SCell is received in slot n, and a CSI report of the CSI reporting process based on the periodic SP CSI-RS configured by the RRC message on the second SCell is transmitted no later than in slot
n
+
T
HARQ
+
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
max( T MAC_CE +T uncertainty_MAC +T FineTime +T SSB ,T uncertainty_RRC +T RRC_delay −T HARQ ),
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, wherein the fourth MAC CE indicates a TCI state for receiving the other one of the PDCCH and the PDSCH of the second 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,
T uncertainty_RRC denotes a period between the reception of the first MAC CE and a reception of the RRC message, and
T RRC_delay denotes a period for processing the RRC message.
13. The apparatus of claim 12 , wherein T activation_time is
max( T uncertainty_MAC +5 ms+ T FineTime ,T uncertainty_RRC +T RRC_delay −T HARQ ).
14. The apparatus of claim 9 , wherein the circuitry is further configured to:
in response to that both the first and second SCells are unknown SCells and operate in the same band that is an FR2 band,
perform a cell search on the first SCell;
transmit an RSRP measurement report indicating RSRP measurements associated with an SSB of the first SCell; and
activate the second SCell without performing cell search and RSRP measurement and reporting over the second SCell.
15. The apparatus of claim 9 , wherein the circuitry is further configured to:
in response to that the first SCell is a known SCell, the second SCell is an unknown SCell, and both the first and second SCells operate in the same band that is a frequency range 1 (FR1) band, activate the first and second SCells in parallel without performing automatic gain control (AGC) gain settling and cell search over the first and second SCells.
16. A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform a method, the method comprising:
receiving on a primary cell (PCell) at a user equipment (UE) a first medium access (MAC) control element (CE) for activating a first secondary cell (SCell) and a second SCell for the UE from a base station in a wireless communication system, the first and second SCells operating in a same band, no active serving cell operating on the same band for the UE; and
activating the first and second SCells in parallel without performing cell search and reference signal received power (RSRP) measurement and reporting over the first and second SCells, in response to having the first SCell as a known SCell, the second SCell as an unknown SCell, and both the first and second SCells operating in the same band that is a frequency range 2 (FR2) band wherein
the first SCell is the known SCell when the UE has transmitted an RSRP measurement report of the first SCell to the base station, and an interval between sending the RSRP measurement report and the receiving of the first MAC CE is shorter than a predefined time,
the activating the first and second SCells in parallel includes:
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 second SCell;
performing a time-frequency tracking process on the second SCell based on an SSB indicated in the first TCI state; and
in response to receiving a third MAC CE on the PCell for activating a semi-persistent (SP) channel state information reference signal (CSI-RS) resource set of the second 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 second SCell, and
the first MAC CE for activating the first and second SCells is received in slot n, and a CSI report of the CSI reporting process based on the SP CSI-RS resource set activated by the third MAC CE on the second SCell is transmitted no later than in slot
n
+
T
HARQ
+
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, wherein the fourth MAC CE indicates a second TCI state for receiving another one of the PDCCH and the PDSCH of the second 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.