A method of performing an uplink, UL, transmission by a user equipment, UE, in a wireless communication system, the method comprising: performing first type sensing on beams, wherein each of the beams is sensed independently; performing the UL transmission through the beams sensed to be idle, wherein random back-off counter values used for the first type sensing are set independently to each other, wherein the performing the UL transmission further comprises: based on that [i] a first beam among the beams is sensed to be idle based on the first type sensing before a transmission time of the UL transmission corresponding to the first beam and [ii] the UL transmission has not been performed after the first type sensing: performing second type sensing on the first beam during a duration immediately before the transmission time, wherein the random back-off counter values are not used for the second type sensing; performing the UL transmission based on that the first beam is sensed to be idle based on the second type sensing; and performing the first type sensing on the first beam based on the first beam being sensed to be busy based on the second type sensing. performing first type sensing on beams, wherein each of the beams is sensed independently; performing the UL transmission through the beams sensed to be idle, wherein random back-off counter values used for the first type sensing are set independently to each other, wherein the performing the UL transmission further comprises: based on that [i] a first beam among the beams is sensed to be idle based on the first type sensing before a transmission time of the UL transmission corresponding to the first beam and [ii] the UL transmission has not been performed after the first type sensing: performing second type sensing on the first beam during a duration immediately before the transmission time, wherein the random back-off counter values are not used for the second type sensing; performing the UL transmission based on that the first beam is sensed to be idle based on the second type sensing; and performing the first type sensing on the first beam based on the first beam being sensed to be busy based on the second type sensing. based on that [i] a first beam among the beams is sensed to be idle based on the first type sensing before a transmission time of the UL transmission corresponding to the first beam and [ii] the UL transmission has not been performed after the first type sensing: performing second type sensing on the first beam during a duration immediately before the transmission time, wherein the random back-off counter values are not used for the second type sensing; performing the UL transmission based on that the first beam is sensed to be idle based on the second type sensing; and performing the first type sensing on the first beam based on the first beam being sensed to be busy based on the second type sensing. performing second type sensing on the first beam during a duration immediately before the transmission time, wherein the random back-off counter values are not used for the second type sensing; performing the UL transmission based on that the first beam is sensed to be idle based on the second type sensing; and performing the first type sensing on the first beam based on the first beam being sensed to be busy based on the second type sensing. <EOS>