A method for transmitting a frame in a WLAN system performed by a first wireless device may include: performing a receiving operation for a first STR PPDU within a first time resource based on a wireless channel, wherein the first STR PPDU is received from a second wireless device, and wherein a PHY header includes a BSS color information, an identification information, and an indication information, and, when the first wireless device is indicated by the identification information, in case a NAV timer value according to a logical carrier sense is equal to ‘0’, and in case a result of a physical carrier sense performed for the wireless channel, during a predetermined duration before the receiving operation is started, is in an idle state, performing a transmitting operation for a second STR PPDU within a second time resource overlapping with the first time resource based on the wireless channel.