Methods and apparatuses for power saving operations

1. A method performed by a User Equipment (UE) for power saving operations, the method comprising:

receiving a first Radio Resource Control (RRC) configuration indicating a set of one or more dormancy cell group, a group of serving cells belonging to a first dormancy cell group in the set of one or more dormancy cell groups;

receiving a second RRC configuration indicating a first Bandwidth Part (BWP), on which the UE is configured with a dormant operation, for a serving cell included in the group of serving cells belonging to the first dormancy cell group, the dormant operation including performing a Channel State Information (CSI) measurement and stopping monitoring a Physical Downlink Control Channel (PDCCH);

receiving a third RRC configuration indicating a second BWP, on which the UE is not configured with the dormant operation, for the serving cell;

receiving a Power Saving Signal (PSS) including a bitmap, each bit in the bitmap associated with one dormancy cell group of the set of one or more dormancy cell groups; and

switching, based on a bit in the bitmap that is associated with the first dormancy cell group in the set of one or more dormancy cell groups, active BWPs of all serving cells included in the group of serving cells belonging to the first dormancy cell group to the first BWP or the second BWP.

2. The method of claim 1 , further comprising:

performing the dormant operation on the serving cell in a case that the active BWP of the serving cell is determined as the first BWP.

3. The method of claim 1 , further comprising:

stopping monitoring the PDCCH on the serving cell in a case that the active BWP of the serving cell is determined as the first BWP; and

monitoring the PDCCH on the serving cell in a case that the active BWP of the serving cell is determined as the second BWP.

4. The method of claim 1 , wherein the dormant operation for the serving cell further includes at least one of:

performing Automatic Gain Control (AGC) for the serving cell, or

performing beam management for the serving cell.

5. The method of claim 1 , wherein the PSS is received by the UE, on a Primary Cell (PCell) or a Special Cell (SpCell), via Downlink Control Information (DCI) that is scrambled by a Power Saving-Radio Network Temporary Identifier (PS-RNTI).

6. The method of claim 1 , wherein the PSS further includes a wake-up indicator for starting a Discontinuous Reception (DRX) On-duration timer (drx-onDurationTimer) at a beginning of a DRX cycle.

7. The method of claim 1 , wherein the UE is configured with a Discontinuous Reception (DRX) operation.

8. The method of claim 1 , further comprising:

stopping monitoring the PSS on a PDCCH monitoring occasion when the UE is in a Discontinuous Reception (DRX) active time, the PDCCH monitoring occasion configured for the PSS; and

monitoring the PSS on the PDCCH monitoring occasion when the UE is not in the DRX active time.

9. The method of claim 1 , wherein the active BWP of the serving cell is a Downlink (DL) BWP.

10. A User Equipment (UE) for power saving operations, the UE comprising:

a memory storing at least one instruction; and

at least one processor coupled to the memory and configured to execute the at least one instruction to:

receive a first Radio Resource Control (RRC) configuration indicating a set of one or more dormancy cell groups, a group of serving cells belonging to a first dormancy cell group in the set of one or more dormancy cell groups;

receive a second RRC configuration indicating a first Bandwidth Part (BWP), on which the UE is configured with a dormant operation, for a serving cell included in the group of serving cells belonging to the first dormancy cell group, the dormant operation including performing a Channel State Information (CSI) measurement and stopping monitoring a Physical Downlink Control Channel (PDCCH), the serving cell belonging to a dormancy cell group of the at least one dormancy cell group;

receive a third RRC configuration indicating a second BWP, on which the UE is not configured with the dormant operation, for the serving cell;

receive a Power Saving Signal (PSS) including a bitmap, each bit in the bitmap associated with one dormancy cell group of the set of one or more dormancy cell groups; and

switch, based on a bit in the bitmap that is associated with the first dormancy cell group in the set of one or more dormancy cell groups, active BWPs of all serving cells included in the group of serving cells belonging to the first dormancy cell group to the first BWP or the second BWP.

11. The UE of claim 10 , wherein the at least one processor is further configured to execute the at least one instruction to:

perform the dormant operation on the serving cell in a case that the active BWP of the serving cell is determined as the first BWP.

12. The UE of claim 10 , wherein the at least one processor is further configured to execute the at least one instruction to:

stop monitoring the PDCCH on the serving cell in a case that the active BWP of the serving cell is determined as the first BWP; and

monitor the PDCCH on the serving cell in a case that the active BWP of the serving cell is determined as the second BWP.

13. The UE of claim 10 , wherein the dormant operation for the serving cell further includes at least one of:

performing Automatic Gain Control (AGC) for the serving cell, or

performing beam management for the serving cell.

14. The UE of claim 10 , wherein the PSS is received by the UE, on a Primary Cell (PCell) or a Special Cell (SpCell), via Downlink Control Information (DCI) that is scrambled by a Power Saving-Radio Network Temporary Identifier (PS-RNTI).

15. The UE of claim 10 , wherein the PSS further includes a wake-up indicator for starting a Discontinuous Reception (DRX) On-duration timer (drx-onDurationTimer) at a beginning of a DRX cycle.

16. The UE of claim 10 , wherein the UE is configured with a Discontinuous Reception (DRX) operation.

17. The UE of claim 10 , wherein the at least one processor is further configured to execute the at least one instruction to:

stop monitoring the PSS on a PDCCH monitoring occasion when the UE is in a Discontinuous Reception (DRX) active time, the PDCCH monitoring occasion being configured for the PSS; and

monitor the PSS on the PDCCH monitoring occasion when the UE is not in the DRX active time.

18. The UE of claim 10 , wherein the active BWP of the serving cell is a Downlink (DL) BWP.