Method and apparatus for performing CSI report in NR V2X

1. A method for performing sidelink communication by a first device, the method comprising:

establishing a plurality of PC5 radio resource control (RRC) connections with a second device;

receiving, from the second device through the plurality of PC5 RRC connections, information regarding latency bounds for sidelink (SL) channel state information (CSI) reporting, wherein each of the latency bounds is maintained for each of the plurality of PC5 RRC connections;

triggering SL CSI reporting related to a first PC5 RRC connection among the plurality of PC5 RRC connections;

receiving, from the second device, a CSI-reference signal (RS) related to the triggered SL CSI reporting;

determining that transmission of the triggered SL CSI reporting with at least one SL grant cannot fulfil a latency bound for the triggered SL CSI reporting; and

transmitting, to a base station, a scheduling request (SR) for requesting a resource for the triggered SL CSI reporting, based on the transmission of the triggered SL CSI reporting with the at least one SL grant which cannot fulfil the latency bound for the triggered SL CSI reporting.

2. The method of claim 1 , wherein the transmission of the triggered SL CSI reporting with the at least one SL grant which cannot fulfil the latency bound for the triggered SL CSI reporting indicates that no SL grant for transmission of the triggered SL CSI reporting is within the latency bound for the triggered SL CSI reporting.

3. The method of claim 1 , wherein the first device is configured with SL resource allocation mode in which the base station schedules an SL communication.

4. The method of claim 1 , further comprising:

receiving, from the base station, a SL grant in response to the SR; and

canceling the triggered SL CSI reporting, based on the SL grant which cannot fulfil the latency bound for the triggered SL CSI reporting.

5. The method of claim 4 , wherein the triggered SL CSI reporting is canceled based on expiration of the latency bound for the triggered SL CSI reporting.

6. The method of claim 4 , wherein canceling the triggered SL CSI reporting comprises: flushing a SL CSI reporting medium access control (MAC) control element (CE) in a buffer of the first device before transmitting the SL CSI reporting MAC CE to the second device.

7. The method of claim 1 , further comprising:

generating a SL CSI reporting medium access control (MAC) control element (CE) based on the CSI-RS.

8. The method of claim 1 ,

wherein the plurality of PC5 RRC connections include the first PC5 RRC connection and a second PC5 RRC connection,

wherein the latency bound related to the SL CSI reporting is determined to be a minimum value for the latency bound related to the first PC5 RRC connection and a latency bound related to the second PC5 RRC connection, and

wherein the latency bound related to the first PC5 RRC connection and the latency bound related to the second PC5 RRC connection are different.

9. A first device configured to perform sidelink communication, the first device comprising:

at least one memory storing instructions;

at least one transceiver; and

at least one processor operatively connected to the at least one memory and the at least one transceiver, wherein the at least one processor executes the instructions to:

establish a plurality of PC5 radio resource control (RRC) connections with a second device;

control the at least one transceiver to receive, from the second device through the plurality of PC5 RRC connections, information regarding latency bounds for sidelink (SL) channel state information (CSI) reporting, wherein each of the latency bounds is maintained for each of the plurality of PC5 RRC connections;

trigger SL CSI reporting related to a first PC5 RRC connection among the plurality of PC5 RRC connections;

control the at least one transceiver to receive, from the second device, a CSI-reference signal (RS) related to the triggered SL CSI reporting;

determine that transmission of the triggered SL CSI reporting with at least one SL grant cannot fulfil a latency bound for the triggered SL CSI reporting; and

control the at least one transceiver to transmit, to a base station, a scheduling request (SR) for requesting a resource for the triggered SL CSI reporting, based on the transmission of the triggered SL CSI reporting with the at least one SL grant which cannot fulfil the latency bound for the triggered SL CSI reporting.

10. The first device of claim 9 , wherein the transmission of the triggered SL CSI reporting with the at least one SL grant which cannot fulfil the latency bound for the triggered SL CSI reporting indicates that no SL grant for transmission of the triggered SL CSI reporting is within the latency bound for the triggered SL CSI reporting.

11. The first device of claim 9 , wherein the first device is configured with SL resource allocation mode in which the base station schedules an SL communication.

12. The first device of 9 , wherein the at least one processor further executes the instructions to: control the at least one transceiver to receive, from the base station, a SL grant in response to the SR, and cancel the triggered SL CSI reporting, based on the SL grant which cannot fulfil the latency bound for the triggered SL CSI reporting.

13. An apparatus configured to control a first user equipment (UE), the apparatus comprising:

at least one processor; and

at least one memory operatively connected to the at least one processor and storing instructions, wherein the at least one processor executes the instructions to:

establish a plurality of PC5 radio resource control (RRC) connections with a second device;

receive, from the second device through the plurality of PC5 RRC connections, information regarding latency bounds for sidelink (SL) channel state information (CSI) reporting, wherein each of the latency bounds is maintained for each of the plurality of PC5 RRC connections;

trigger SL CSI reporting related to a first PC5 RRC connection among the plurality of PC5 RRC connections;

receive, from the second UE, a CSI-reference signal (RS) related to the triggered SL CSI reporting;

determine that transmission of the triggered SL CSI reporting with at least one SL grant cannot fulfil a latency bound for the triggered SL CSI reporting; and

transmit, to a base station, a scheduling request (SR) for requesting a resource for the triggered SL CSI reporting, based on the transmission of the triggered SL CSI reporting with the at least one SL grant which cannot fulfil the latency bound for the triggered SL CSI reporting.

14. The apparatus of claim 13 , wherein the transmission of the triggered SL CSI reporting with the at least one SL grant which cannot fulfil the latency bound for the triggered SL CSI reporting indicates that no SL grant for transmission of the triggered SL CSI reporting is within the latency bound for the triggered SL CSI reporting.

15. The apparatus of claim 13 , wherein the first UE is configured with SL resource allocation mode in which the base station schedules an SL communication.

16. The apparatus of claim 13 , wherein the at least one processor further executes the instructions to: receive, from the base station, a SL grant in response to the SR, and cancel the triggered SL CSI reporting, based on the SL grant which cannot fulfil the latency bound for the triggered SL CSI reporting.

17. The apparatus of claim 13 ,

wherein the plurality of PC5 RRC connections include the first PC5 RRC connection and a second PC5 RRC connection, and

wherein the latency bound related to the first PC5 RRC connection and a latency bound related to the second PC5 RRC connection are same.