A method and apparatus for operation of a node (102, 104, 106) within a mobile ad hoc cognitive radio network (100) is provided. The method includes sensing at least one assigned communications channel. Sensing at least one assigned communications channel includes measuring a value of at least one parameter corresponding to the communications channel (302). The method further includes comparing the measured value of the at least one parameter with a set of stored values of the at least one parameter (304) to determine a change in the measured values. Finally a sleep mode of the node is activated (306) for a time period, wherein the time period is determined using the change in the measured values.