Sidelink channel state information report
A first wireless device receives, from a base station, configuration parameters of a scheduling request for a sidelink buffer status report (BSR) of a sidelink between the first wireless device and a second wireless device. The scheduling request is triggered for the sidelink BSR in response to data becoming available for transmission to the second wireless device via the sidelink. The first wireless transmits, based on the triggering and to the base station, a preamble for a random access procedure to obtain a first uplink grant to transmit the sidelink B SR. The sidelink BSR is transmitted via a second uplink grant different from the first uplink grant indicated in a random access response corresponding to the preamble. The random access procedure is stopped in response to transmitting the sidelink BSR.
1. A method comprising:
receiving, by a first wireless device from a base station, configuration parameters of:
a first scheduling request for a sidelink channel state information (SL-CSI) report medium access control (MAC) control element (CE); and
a second scheduling request for uplink transmissions to the base station;
triggering, by the first wireless device and in response to no sidelink grant being available for a SL-CSI report transmission, the first scheduling request for sidelink resources for the SL-CSI report transmission to a second wireless device;
initiating a random access procedure based on no physical uplink control channel (PUCCH) resource being available for the first scheduling request for the sidelink resources;
transmitting, by the first wireless device to the base station, a preamble in response to the initiating;
transmitting a SL-CSI report MAC CE to the second wireless device and via a sidelink grant received from the base station; and
stopping the random access procedure, ongoing between the first wireless device and the base station, in response to the transmitting to the second wireless device the SL-CSI report MAC CE via the sidelink grant.
2. The method of claim 1 , wherein the configuration parameters are received in one or more radio resource control (RRC) message from the base station.
3. The method of claim 1 , further comprising triggering a second scheduling request for uplink channel resources for uplink data transmission to the base station in response to no uplink channel resources being available for the uplink data transmission to the base station.
4. The method of claim 1 , wherein the sidelink grant comprises at least one of:
a first physical sidelink shared channel resource, configured by the base station, for transmitting the SL-CSI report MAC CE to the second wireless device; and
a second physical sidelink shared channel resource, selected by the first wireless device, transmitting the SL-CSI report MAC CE to the second wireless device.
5. The method of claim 1 , further comprising monitoring a physical downlink control channel for detecting a random access response in response to transmitting the preamble.
6. The method of claim 5 , wherein the random access response comprises an uplink grant indicating physical uplink shared channel resources for an uplink transmission to the base station, wherein the uplink grant is different from the sidelink grant.
7. The method of claim 1 , wherein the stopping the random access procedure comprises stopping the random access procedure before transmitting the preamble.
8. The method of claim 1 , wherein the stopping the random access procedure comprises stopping monitoring of a physical downlink control channel for a random access response for the preamble.
9. The method of claim 1 , wherein the SL-CSI report MAC CE comprises a rank indicator and a channel quality indicator based on a reference signal associated with the second wireless device.
10. The method of claim 1 , further comprising determining that no physical uplink control channel (PUCCH) resource is available for the scheduling request for the sidelink resources based on at least one of:
the sidelink resources not being configured with a PUCCH resource; or
the sidelink resources being configured with an invalid PUCCH resource.
11. A first wireless device comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors, cause the first wireless device to:
receive, from a base station, configuration parameters of:
a first scheduling request for a sidelink channel state information (SL-CSI) report medium access control (MAC) control element (CE); and
a second scheduling request for uplink transmissions to the base station;
trigger, in response to no sidelink grant being available for a SL-CSI report transmission, the first scheduling request for sidelink resources for the SL-CSI report transmission to a second wireless device;
initiate a random access procedure based on no physical uplink control channel (PUCCH) resource being available for the first scheduling request for the sidelink resources;
transmit, to the base station, a preamble in response to the initiating;
transmit a SL-CSI report MAC CE to the second wireless device and via a sidelink grant received from the base station; and
stop the random access procedure, ongoing between the first wireless device and the base station, in response to the transmitting to the second wireless device the SL-CSI report MAC CE via the sidelink grant.
12. The first wireless device of claim 11 , wherein the configuration parameters are received in one or more radio resource control (RRC) message from the base station.
13. The first wireless device of claim 11 , wherein the instructions further cause the first wireless device to trigger a second scheduling request for uplink channel resources for uplink data transmission to the base station in response to no uplink channel resources being available for the uplink data transmission to the base station.
14. The first wireless device of claim 11 , wherein the sidelink grant comprises at least one of:
a first physical sidelink shared channel resource, configured by the base station, for transmitting the SL-CSI report MAC CE to the second wireless device; and
a second physical sidelink shared channel resource, selected by the first wireless device, transmitting the SL-CSI report MAC CE to the second wireless device.
15. The first wireless device of claim 11 , wherein the instructions further cause the first wireless device to monitor a physical downlink control channel for detecting a random access response in response to transmitting the preamble.
16. The first wireless device of claim 15 , wherein the random access response comprises an uplink grant indicating physical uplink shared channel resources for an uplink transmission to the base station, wherein the uplink grant is different from the sidelink grant.
17. The first wireless device of claim 11 , wherein to stop the random access procedure, the instructions further cause the first wireless device to stop the random access procedure before transmitting the preamble.
18. The first wireless device of claim 11 , wherein to stop the random access procedure, the instructions further cause the first wireless device to stop monitoring of a physical downlink control channel for a random access response for the preamble.
19. The first wireless device of claim 11 , wherein the SL-CSI report MAC CE comprises a rank indicator and a channel quality indicator based on a reference signal associated with the second wireless device, and wherein the reference signal is received from the second wireless device.
20. A non-transitory computer readable medium comprising instructions that, when executed by one or more processors, cause a first wireless device to:
receive, from a base station, configuration parameters of:
a first scheduling request for a sidelink channel state information (SL-CSI) report medium access control (MAC) control element (CE); and
a second scheduling request for uplink transmissions to the base station;
trigger, in response to no sidelink grant being available for a SL-CSI report transmission, the first scheduling request for sidelink resources for the SL-CSI report transmission to a second wireless device;
initiate a random access procedure based on no physical uplink control channel (PUCCH) resource being available for the first scheduling request for the sidelink resources;
transmit, to the base station, a preamble in response to the initiating;
transmit a SL-CSI report MAC CE to the second wireless device and via a sidelink grant received from the base station; and
stop the random access procedure, ongoing between the first wireless device and the base station, in response to the transmitting to the second wireless device the SL-CSI report MAC CE via the sidelink grant.