Spectrum-aware underwater networks

Because communication capacity is severely limited in underwater acoustic environments, due to spectrum scarcity in the uniquely challenging characteristics of underwater acoustic communications (UACs), there is a need for spectrum-aware underwater networks. As such, this article proposes cognitive acoustic communications (CAC) empowering spectrum-aware underwater networks (SUNs), inspired from a cognitive radio (CR) paradigm in wireless terrestrial communications. The capacity gain that can be achieved via CAC in SUN by simulation experiments is explored, and the authors investigate the advantages and limitations of SUN along with its tradeoffs for DSA and OSA separately. It is clear that SUN can reach higher capacities than traditional fixed-spectrum approaches with the help of CAC capability. It is expected that better recognition for the capabilities of SUN will be provided and further research efforts to explore this favorable area will be actuated by this article.