16.9.9.3 Sidelink Specific Consistent LBT Failure

SL-specific consistent LBT failure detection and recovery procedure is supported for SL-U. When the UE detects SL-specific consistent LBT failure, it performs the actions as specified in TS 38.321 [6]. SL-specific consistent LBT failure detection is per RB-set.

A SL UE in RRC_CONNECTED can indicate SL-specific consistent LBT failure to the gNB using a SL MAC CE that indicates the RB set(s) where SL-specific consistent LBT failure was detected. A SL UE using mode 2 resource allocation triggers resource reselection and/or resource pool reselection upon SL-specific consistent LBT failure. In such case, resources in failed RB set(s) are excluded from resource (re)selection until consistent LBT failure on the RB set(s) is cancelled based on conditions in TS 38.321 [6]. The UE triggers SL RLF for all PC5-RRC connections when the UE has triggered SL-specific consistent LBT failure in all RB sets.