AbstractAdvances in underwater acoustic communications technology are being enabled by more access to in-water data and an infusion of new techniques, researchers, and students. In-water data collection is being made possible by robust funding in the United States, the European
Union, and other countries, typically to multiorganization consortia working on both physical and network layer research. At the physical layer, single and multicarrier modulation methods continue to be refined, with a focus on both low signal-to-noise ratio, low-rate and high signal-to-noise
ratio, high-rate data links. Establishment of performance metrics for adaptive equalizers and other parts of the physical layer continue, and recent work on high-fidelity channel models that mimic the effects of small-scale ocean processes indicates that progress is being made.Research
in undersea acoustic networks continues to gain momentum as well, with multiple options available for integrating acoustic propagation models with network simulation, providing common frameworks for basing network design. The combination of these recent advances, plus continued interest by
maritime science and industry in wireless communications, means that the field is poised to make new commercial breakthroughs in the next several years.
Underwater Acoustic Communications: Design Considerations on the Physical Layer