Secondary cell dormancy for new radio carrier aggregation
A UE may enter a dormant state, e.g., for power savings. The systems, methods, and apparatus described herein may provide ways for the UE to transition between an active state and a dormant state, as well as UE behavior in a dormant state. The apparatus may be a UE configured to receive an indication of a bandwidth part (BWP) switch for a secondary cell and to transition between an active state and a dormant state for the secondary cell based on the indication of the BWP switch.
1. A method of wireless communication at a User Equipment (UE), comprising:
receiving a transmission comprising an indication of a bandwidth part (BWP) switch for a secondary cell;
switching BWPs in response to receiving the indication of the BWP switch; and
transitioning the secondary cell between an active state and a dormant state in response to receiving the indication of the BWP switch.
2. The method of claim 1 , wherein the UE skips control channel monitoring for the secondary cell while the secondary cell is in the dormant state.
3. The method of claim 1 , wherein the indication is comprised in downlink control information (DCI) received from a primary cell.
4. The method of claim 3 , wherein the downlink control information comprises a null assignment.
5. The method of claim 1 , wherein the dormant state corresponds to a BWP associated with the secondary cell.
6. The method of claim 5 , wherein the secondary cell is in the dormant state when the BWP associated with the secondary cell becomes active.
7. The method of claim 5 , wherein the BWP is configured based on at least one of an empty control resource set (CORESET), an empty search space, or an empty set of search candidates in a search space.
8. The method of claim 5 , wherein a bandwidth of the BWP associated with the secondary cell comprises a full bandwidth of the secondary cell.
9. The method of claim 1 , wherein the indication is based on an inactivity timer.
10. The method of claim 1 , wherein the dormant state comprises a configuration for at least one of:
an increased control channel monitoring period for the secondary cell relative to the active state,
an increased Channel State Information (CSI) measurement period for the secondary cell relative to the active state,
an increased Sounding Reference Signal (SRS) transmission period for the secondary cell relative to the active state,
a reduction in Radio Resource Management (RRM) measurement or duration relative to the active state,
beam management performance based on the increased CSI measurement period relative to the active state,
beam failure recovery performance through a primary cell, or
an increased minimum scheduling offset relative to the active state.
11. The method of claim 10 , wherein the secondary cell is self-scheduled on the secondary cell.
12. The method of claim 1 , wherein a primary cell comprises a primary cell (PCell) or a primary secondary cell-group cell (PSCell).
13. The method of claim 1 , wherein the indication indicates a BWP switch of a primary cell from a first BWP to a second BWP, and wherein the UE transitions at least one secondary cell from the active state and the dormant state based on the BWP switch of the primary cell, and wherein when the primary cell switches from the second BWP, the UE transitions from the dormant state to the active state for the secondary cell.
14. The method of claim 1 , wherein the secondary cell is cross-carrier scheduled using a primary cell, and wherein the dormant state for the secondary cell comprises a configuration for at least one of:
an increased control channel monitoring period for the secondary cell on the primary cell relative to the active state,
an increased Channel State Information (CSI) measurement period for the secondary cell relative to the active state,
an increased Sounding Reference Signal (SRS) transmission period for the secondary cell relative to the active state,
a reduction in a Radio Resource Management (RRM) measurement or duration relative to the active state,
beam management performance based on the increased CSI measurement period relative to the active state,
beam failure recovery performance through the primary cell, or
an increased minimum scheduling offset relative to the active state.
15. The method of claim 1 , wherein the UE transitions to the dormant state by applying a dormant state configuration to an active BWP of the secondary cell, wherein the active BWP of the secondary cell comprises a first set of parameters for the active state and a second set of parameters for the dormant state, wherein the second set of parameters comprises a scaling factor for at least one of a control channel monitoring period, a Channel State Information (CSI) measurement period, or a Sounding Reference Signal (SRS) transmission period.
16. The method of claim 1 , wherein the UE transitions to the dormant state by applying a set of parameters for the dormant state to a component carrier of the secondary cell, and wherein the set of parameters for the dormant state comprises a scaling factor for at least one of a control channel monitoring period, a Channel State Information (CSI) measurement period, or a Sounding Reference Signal (SRS) transmission period.
17. The method of claim 1 , wherein the indication is associated with a Discontinuous Reception (DRX) state of the UE.
18. The method of claim 1 , wherein the UE infers instructions to transition to the dormant state based on another configuration for at least one of a primary cell or the secondary cell.
19. An apparatus for wireless communication at a User Equipment (UE), comprising:
a memory; and
at least one processor coupled to the memory and configured to:
receive a transmission comprising an indication of a bandwidth part (BWP) switch for a secondary cell;
switch BWPs in response to receiving the indication of the BWP switch; and
transition between an active state and a dormant state for the secondary cell state in response to receiving the indication of the BWP switch.
20. The apparatus of claim 19 , wherein the UE skips control channel monitoring for the secondary cell while in the dormant state for the secondary cell.
21. The apparatus of claim 19 , wherein the indication is comprised in downlink control information (DCI) received from a primary cell.
22. The apparatus of claim 21 , wherein the downlink control information comprises a null assignment.
23. The apparatus of claim 19 , wherein the dormant state corresponds to a BWP configured for the secondary cell, wherein the secondary cell is in the dormant state when the BWP associated with the secondary cell becomes active.
24. A method of wireless communication at a base station, comprising:
determining to transition a User Equipment (UE) between an active state and a dormant state for a secondary cell; and
transmitting, to the UE, an indication of a bandwidth part (BWP) switch for the secondary cell that indicates for the UE to switch BWPs and to transition the UE between the active state and the dormant state for the secondary cell.
25. The method of claim 24 , wherein the dormant state for the secondary cell comprises a configuration for the UE to skip control channel monitoring for the secondary cell.
26. The method of claim 24 , wherein the indication is comprised in downlink control information (DCI) transmitted on a primary cell.
27. The method of claim 26 , wherein the downlink control information comprises a null assignment.
28. The method of claim 24 , wherein the dormant state corresponds to a BWP associated with the secondary cell.
29. The method of claim 28 , wherein when the secondary cell is in the dormant state when the BWP associated with the secondary cell becomes active.
30. The method of claim 28 , wherein the BWP is configured based on at least one of an empty control resource set (CORESET), an empty search space, or an empty set of search candidates in a search space.