We present a practical measurement-based characterization of the aggregated traffic on microseconds time scale in wireless networks. The model allows estimating the channel utilization for the period of time required to transmit data structures of different sizes (short control frames and a data packet of the maximum size). The presented model opens a possibility to mitigate the effect of interferences in the network by optimizing the communication parameters of the MAC layer (e.g. the size of contention window, retransmission strategy, etc.) for the forthcoming transmission. The article discusses issues and challenges associated with the PHY-layer characterization of the network state.