A method of operating wireless devices includes providing a plurality of sender nodes each having a respective message to wirelessly send to a receiver node. A probability distribution is assigned to a plurality of frequency channels such that a respective probability of selection is assigned to each frequency channel. At least two of the probabilities of selection are unequal. A respective frequency channel is probabilistically selected for each of the sender nodes according to the probability distribution. The messages are wirelessly sent from the sender nodes to the receiver node in the selected frequency channels. The receiver node is used to sample a first one of the frequency channels and a second one of the frequency channels. The second frequency channel has a higher respective probability of selection than the first frequency channel. If the receiver node sensed a signal in both the first frequency channel and the second frequency channel during the sampling, the receiver node is tuned to the first frequency channel and receives a remainder of the message on the first frequency channel.