A method performed by a network node in a first wireless system for channel access comprising: Detecting (S410) one or more wireless systems that coexist with the first wireless system on a channel, the channel operating on a shared spectrum; determining (S420) a channel access scheme based on the detected one or more wireless systems, the channel access scheme being one of listen before talk, LBT, channel access scheme, listen after talk, LAT, channel access scheme, and hybrid LBT and LAT channel access scheme, wherein determining the channel access scheme comprises: determining (S510) whether the detected one or more wireless systems perform LBT channel access scheme or LAT channel access scheme; in response to all of the detected one or more wireless systems performing LBT channel access scheme, determining (S520) the channel access scheme as LBT channel access scheme; in response to all of the detected one or more wireless systems performing LAT channel access scheme, determining (S530) the channel access scheme as LAT channel access scheme; and in response to some of the detected one or more wireless systems performing LBT channel access scheme and some performing LAT channel access scheme, determining (S540) the channel access scheme as hybrid LBT and LAT channel access scheme; and performing (S430) channel access according to the channel access scheme. Detecting (S410) one or more wireless systems that coexist with the first wireless system on a channel, the channel operating on a shared spectrum; determining (S420) a channel access scheme based on the detected one or more wireless systems, the channel access scheme being one of listen before talk, LBT, channel access scheme, listen after talk, LAT, channel access scheme, and hybrid LBT and LAT channel access scheme, wherein determining the channel access scheme comprises: determining (S510) whether the detected one or more wireless systems perform LBT channel access scheme or LAT channel access scheme; in response to all of the detected one or more wireless systems performing LBT channel access scheme, determining (S520) the channel access scheme as LBT channel access scheme; in response to all of the detected one or more wireless systems performing LAT channel access scheme, determining (S530) the channel access scheme as LAT channel access scheme; and in response to some of the detected one or more wireless systems performing LBT channel access scheme and some performing LAT channel access scheme, determining (S540) the channel access scheme as hybrid LBT and LAT channel access scheme; and determining (S510) whether the detected one or more wireless systems perform LBT channel access scheme or LAT channel access scheme; in response to all of the detected one or more wireless systems performing LBT channel access scheme, determining (S520) the channel access scheme as LBT channel access scheme; in response to all of the detected one or more wireless systems performing LAT channel access scheme, determining (S530) the channel access scheme as LAT channel access scheme; and in response to some of the detected one or more wireless systems performing LBT channel access scheme and some performing LAT channel access scheme, determining (S540) the channel access scheme as hybrid LBT and LAT channel access scheme; and performing (S430) channel access according to the channel access scheme. <EOS>