A method performed by a transmitting node (110; 120) for performing data transmissions to at least one receiving node (120; 110) on a radio channel in a wireless communications network (100) is provided. First, the transmitting node sets at least two contention window sizes, wherein the at least two contention window sizes are separately determined based on information associated with the least one receiving node. Then, the transmitting node defers a first transmission of data to the at least one receiving node (120; 110) for a first period of observation of the radio channel determined by a first contention window size of the at least two contention window sizes. The transmitting node also defers at least one second transmission of data to the at least one receiving node (120; 110) for atleast one second period of observation of the radio channel determined by at least a second contention window size of the at least two contention window sizes. Further, the transmitting node performsthe first or the at least one second transmission of data to the at least one receiving node (120; 110) when an outcome of the first or the at least second periods of observation of the radio channel, respectively, is that the radio channel is idle. A transmitting node (110; 120) and a computer program product for performing data transmissions to at least one receiving node (120; 110) on a radiochannel in a wireless communications network (100) are also provided.