Sidelink listen-before-talk failure on a shared spectrum

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:
• select, from a candidate resource set in a first resource pool, a sidelink grant indicating a set of resources for one or more sidelink transmissions;
• determine a listen-before-talk (LBT) failure for a first resource of the set of resources before performing the one or more sidelink transmissions via the first resource;
• remove, based on the LBT failure of the first resource and from the sidelink grant, the first resource;
• select, based on the LBT failure of the first resource and for the one or more sidelink transmissions, a second resource other than the first resource;
• and
• replace, based on the LBT failure of the first resource and for the sidelink grant, the first resource with the second resource.

A method comprising:

• receiving, by a wireless device from a base station, a radio resource control (RRC) message indicating a first resource pool of a sidelink (SL) communication;
• determining, by the wireless device, an SL grant comprising a plurality of resources selected from a candidate resource set in the first resource pool, wherein:
• the plurality of resources are time-frequency resources;
• and
• the SL grant is for one or more SL transmissions of the SL communication;
• receiving, by a medium access control (MAC) layer of the wireless device from a physical layer of the wireless device, an indication of SL listen before talk (LBT) failure of a first time-frequency resource of the plurality of resources of the SL grant;
• based on the indication, selecting, by the wireless device and for the first time-frequency resource, a second time-frequency resource from the first resource pool excluding resources associated with SL LBT failure;
• and
• transmitting the one or more SL transmissions of the SL communication.