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 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 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; 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
a
c
t
i
v
a
tion
_
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
3 ms+max( T uncertainty_MAC +T FineTime +2 ms, T uncertainty_SP ),
where,
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 a synchronization signal block (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 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 CSI-RS configured by the RRC message on the second SCell.
3. The method of claim 2 , 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 CSI-RS of the second SCell is transmitted no later than in slot
n
+
T
HARQ
+
T
a
c
t
i
v
a
tion
_
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 uncertainty_MAC +5 ms+ T FineTime ,T uncertainty_RRC +T RRC_delay −T HARQ ),
where,
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 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.
4. 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.
5. 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.
6. 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).
7. 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 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 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; 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
a
c
t
i
v
a
tion
_
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
3 ms+max( T uncertainty_MAC +T FineTime +2 ms, T uncertainty_SP ),
where,
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 a synchronization signal block (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.
8. The apparatus of claim 7 , 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 CSI-RS configured by the RRC message on the second SCell.
9. The apparatus of claim 8 , 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 CSI-RS configured by the RRC message on the second SCell is transmitted no later than in slot
n
+
T
HARQ
+
T
a
c
t
i
v
a
tion
_
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 uncertainty_MAC +5 ms+ T FineTime ,T uncertainty_RRC +T RRC_delay −T HARQ ),
where,
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 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.
10. The apparatus of claim 7 , 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.
11. The apparatus of claim 7 , 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.
12. 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 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 a,
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; 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
a
c
t
i
v
a
tion
_
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
3 ms+max( T uncertainty_MAC +T FineTime +2 ms, T uncertainty_SP ),
where,
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 a synchronization signal block (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.
13. The non-transitory computer-readable medium of claim 12 , 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 CSI-RS configured by the RRC message on the second SCell.
14. The non-transitory computer-readable medium of claim 13 , 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 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 uncertainty_MAC +5 ms+ T FineTime ,T uncertainty_RRC +T RRC_delay −T HARQ ),
where,
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 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.
15. The non-transitory computer-readable medium of claim 12 , wherein the method further comprises:
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.
16. The non-transitory computer-readable medium of claim 12 , wherein the method further comprises:
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.
17. The non-transitory computer-readable medium of claim 12 , wherein the PCell is a primary cell of a primary cell group (PCG), or a primary cell of a secondary cell group (SCG).