In communication applications, frequency spectrum management has become an important issue due to rapid increase in the number of devices that use the limited frequency spectrum. Efficient spectrum management is a necessity due to resource scarcity. Cognitive radios are emerged as one of the most prominent for solutions for this problem. Recently, the frequency spectrum management implementations of cognitive radios has increased. In this study, channel based spectrum monitoring of 2.4 GHz ISM band is implemented using energy detection method and also software defined radio technology. The channel based usage density of ISM band is shown consistently as the outcome of this study.