UE assistance information report for sidelink DRX

1. A base station (BS) comprising:

a processor configured to generate a first indicator requesting a report of a set of sidelink (SL) discontinuous reception (DRX) configurations for SL communications among user equipments (UEs); and

a transceiver operably connected to the processor, the transceiver configured to:

transmit, to a UE among the UEs, a downlink signal including the first indicator; and

receive, from the UE, an uplink signal including the report of the set of the SL DRX configurations based on the first indicator indicating that the report of the set of the SL DRX configurations is requested,

wherein the processor is further configured to configure, based on the report of the set of the SL DRX configurations, a network DRX configuration for an interface between a UE and a network entity including the BS.

2. The BS of claim 1 , wherein:

the report of the set of the SL DRX configurations comprises at least one of a source layer-2 identification (ID) or a destination layer-2 ID if a SL DRX operation is applied to a SL communication with a neighbor UE based on the at least one of the source layer-2 ID or the destination layer-2 ID; or

the report of the set of the SL DRX configurations comprises information for entire SL communications with other UEs in which the UE participates if the SL DRX operation is applied to the entire SL communications, the entire SL communications comprising at least one of a unicast SL communication, a broadcast communication, or a groupcast communication.

3. The BS of claim 1 , wherein:

the transceiver is further configured to receive a second indicator via the uplink signal or another uplink signal that is received before receiving the uplink signal; and

the second indicator indicates whether a SL DRX operation is applied for entire SL communications or part of the entire SL communications in which the UE is participated.

4. The BS of claim 1 , wherein at least one of the set of the SL DRX configurations includes at least one of a source layer-2 ID, a destination layer-2 ID, or active time information including a value of a SL DRX on-duration timer, a value of a SL DRX inactivity timer, a value of a SL hybrid automatic repeat request (HARQ) retransmission timer, a value of a SL HARQ round trip timer (RTT) timer, a value of a SL DRX cycle length, and a value of a SL DRX start offset.

5. The BS of claim 1 , wherein at least one of the set of the SL DRX configurations includes at least one of a destination layer-2 ID or active reception time information for the SL communications when the UE is configured for the SL communications with other UEs, the active reception time information being used for a channel sensing operation to select resources for the SL communications.

6. The BS of claim 1 , wherein:

the transceiver is further configured to receive the uplink signal including the report of the set of the SL DRX configurations that comprise part of the set of the SL DRX configurations; and

the part of the set of the SL DRX configurations includes at least one of a value of a SL DRX on-duration timer, a value of a SL DRX cycle length, or a value of a SL DRX start offset.

7. The BS of claim 1 , wherein the processor is further configured to:

configure, based on the set of the SL DRX configurations, a value of a DRX active timer of the network DRX configuration, the value of the DRX active timer not overlapping with a value of a SL DRX active timer when the UE is configured with a single radio frequency (RF) chain; or

configure, based on the set of the SL DRX configurations, the value of the DRX active timer of the network DRX configuration, the value of the DRX active timer overlapping with the value of the SL DRX active timer when the UE is configured with multiple RF chains.

8. A method of a base station (BS), the method comprising:

generating a first indicator requesting a report of a set of sidelink (SL) discontinuous reception (DRX) configurations for SL communications among user equipments (UEs);

transmitting, to a UE among the UEs, a downlink signal including the first indicator;

receiving, from the UE, an uplink signal including the report of the set of the SL DRX configurations based on the first indicator indicating that the report of the set of the SL DRX configurations is requested; and

configuring, based on the report of the set of the SL DRX configurations, a network DRX configuration for an interface between a UE and a network entity including the BS.

9. The method of claim 8 , wherein:

the report of the set of the SL DRX configurations comprises at least one of a source layer-2 identification (ID) or a destination layer-2 ID if a SL DRX operation is applied to a SL communication with a neighbor UE based on the at least one of the source layer-2 ID or the destination layer-2 ID; or

the report of the set of the SL DRX configurations comprises information for entire SL communications with other UEs in which the UE participates if the SL DRX operation is applied to the entire SL communications, the entire SL communications comprising at least one of a unicast SL communication, a broadcast communication, or a groupcast communication.

10. The method of claim 8 , further comprising receiving a second indicator via the uplink signal or another uplink signal that is received before receiving the uplink signal, wherein the second indicator indicates whether a SL DRX operation is applied for entire SL communications or part of the entire SL communications in which the UE is participated.

11. The method of claim 8 , wherein at least one of the set of the SL DRX configurations includes at least one of a source layer-2 ID, a destination layer-2 ID, or active time information including a value of a SL DRX on-duration timer, a value of a SL DRX inactivity timer, a value of a SL hybrid automatic repeat request (HARQ) retransmission timer, a value of a SL HARQ round trip timer (RTT) timer, a value of a SL DRX cycle length, and a value of a SL DRX start offset.

12. The method of claim 8 , wherein at least one of the set of the SL DRX configurations includes at least one of a destination layer-2 ID or active reception time information for the SL communications when the UE is configured for the SL communications with other UEs, the active reception time information being used for a channel sensing operation to select resources for the SL communications.

13. The method of claim 8 , further comprising receiving the uplink signal including the report of the set of the SL DRX configurations that comprise part of the set of the SL DRX configurations,

wherein the part of the set of the SL DRX configurations includes at least one of a value of a SL DRX on-duration timer, a value of a SL DRX cycle length, or a value of a SL DRX start offset.

14. The method of claim 8 , further comprising:

configuring, based on the set of the SL DRX configurations, a value of a DRX active timer of the network DRX configuration, the value of the DRX active timer not overlapping with a value of a SL DRX active timer when the UE is configured with a single radio frequency (RF) chain; or

configuring, based on the set of the SL DRX configurations, the value of the DRX active timer of the network DRX configuration, the value of the DRX active timer overlapping with the value of the SL DRX active timer when the UE is configured with multiple RF chains.

15. A user equipment (UE) comprising:

a processor; and

a transceiver operably connected to the processor, the transceiver configured to:

receive, from a base station (BS), a downlink signal including a first indicator requesting a report of a set of sidelink (SL) discontinuous reception (DRX) configuration for SL communications with other UEs; and

transmit, to the BS, an uplink signal including the report of the set of the SL DRX configurations based on the first indicator indicating that the report of the set of the SL DRX configurations is requested,

wherein a network DRX configuration is configured, based on the report of the set of the SL DRX configurations, for an interface between the UE and a network entity including a BS communicating with the UE.

16. The UE of claim 15 , wherein:

the report of the set of the SL DRX configurations comprises at least one of a source layer-2 identification (ID) or a destination layer-2 ID if a SL DRX operation is applied to a SL communication with a neighbor UE based on the at least one of the source layer-2 ID or the destination layer-2 ID; or

the report of the set of the SL DRX configurations comprises information for entire SL communications with other UEs in which the UE participates if the SL DRX operation is applied to the entire SL communications, the entire SL communications comprising at least one of a unicast SL communication, a broadcast communication, or a groupcast communication.

17. The UE of claim 15 , wherein:

the transceiver is further configured to transmit a second indicator via the uplink signal or another uplink signal that is transmitted before transmitting the uplink signal; and

the second indicator indicates whether a SL DRX operation is applied for entire SL communications or part of the entire SL communications in which the UE is participated.

18. The UE of claim 15 , wherein:

at least one of the set of the SL DRX configurations includes at least one of a source layer-2 ID, a destination layer-2 ID, or active time information including a value of a SL DRX on-duration timer, a value of a SL DRX inactivity timer, a value of a SL hybrid automatic repeat request (HARQ) retransmission timer, a value of a SL HARQ round trip timer (RTT) timer, a value of a SL DRX cycle length, and a value of a SL DRX start offset; or

the at least one of a set of the SL DRX configurations includes at least one of the destination layer-2 ID or active reception time information for the SL communications when the UE is configured for the SL communications with other UEs, the active reception time information being used for a channel sensing operation to select resources for the SL communications.

19. The UE of claim 15 , wherein:

the transceiver is further configured to transmit the uplink signal including the report of the set of the SL DRX configurations that comprise part of the set of the SL DRX configurations; and

the part of the set of the SL DRX configurations includes at least one of a value of a SL DRX on-duration timer, a value of a SL DRX cycle length, or a value of a SL DRX start offset.

20. The UE of claim 15 , wherein the processor is further configured to:

identify, based on the set of the SL DRX configurations, a value of a DRX active timer of the network DRX configuration, the value of the DRX active timer not overlapping with a value of a SL DRX active timer when the UE is configured with a single radio frequency (RF) chain; or

identify, based on the set of the SL DRX configurations, the value of the DRX active timer of the network DRX configuration, the value of the DRX active timer overlapping with the value of the SL DRX active timer when the UE is configured with multiple RF chains.