In one embodiment, a sensing device (200) can include a transceiver (202) to monitor a communication signal, and a controller (203) communicatively coupled to the transceiver to receive from a Cluster Head (140) a schedule comprising a listening period and an active sensing period. During the listening period, the sensing device can monitor an occupied communication channel of the communication signal. During the active sensing period the sensing device can transmit in the occupied communication channel a test signal. The sensing device can increase a duty cycle of the test signal during repeated transmission, and calculate a correlation between a duration of the occupancy caused by an incumbent transmitting a communication signal in the communication channel and a duration of the test signal. A negative correlation can indicate the presence of an incumbent Carrier Sensing Multiple Access (CSMA) node transmitting a communication signal in the network.