A user equipment (UE) measures a sidelink (SL) resource occupancy level, and reports the measured SL resource occupancy level to an eNodeB (eNB). The measured SL resource occupancy level may be reported to the eNB when a predetermined event occurs. For example, the predetermined event may be a case in which the measured SL resource occupancy level is greater than or less than a threshold value. The SL resource occupancy level may be referred to as a channel busy ratio (CBR).