BALAJI K*
To develop an eco-friendly Underwater Cognitive Acoustic Networks (UCANs) with high spectrum utilization. The huge number of sensor networks is installed in the Underwater to enable applications for oceanographic data collection, pollution and corrosion monitoring, offshore exploration, disaster prevention, assisted navigation and tactical surveillance applications. For feasible applications, there is a need to enable the underwater communications among the underwater devices. The latest developments in the wireless communications cause the spectrum shortage problems in the oceans. Cognitive Acoustic (CA) is the enabling technology for supporting dynamic spectrum access technique in wireless communication. The CA provides the solution for spectrum scarcity problem that is encountered in many countries. In oceans, both the natural acoustic systems and artificial acoustic systems use acoustic signal for communication. To efficiently utilize the spectrum without interference with other acoustic systems, a smart UAN should be designed with aware of the surrounding environment and ability to reconfigure their operation parameters such as frequency band, modulation schemes and transmission power.