Efficient MAC-layer spectrum sensing scheme over underwater cognitive acoustic networks

The cognitive access techniques were originally developed for radio communication networks, and are recently extended to the research area for underwater acoustic networks. One of the important problems for developing the underwater cognitive acoustic networks lies in the optimal spectrum sensing strategy to maximize the exploitation of spectrum holes, which are the idle channels due to the absence of the primary acoustic user. To overcome this challenge, we propose the media access control (MAC)-layer spectrum sensing scheme to find the spectrum hole with minimum channel switching delay while obtaining the maximum signal-to-noise ratio. Using our proposed MAC-layer spectrum sensing scheme, the secondary underwater acoustic users efficiently reduce the channel switching delay.