On the Benefits of High Absorption in Practical Multi-hop Networks

Underwater acoustic communications in their present form do not appear to provide an ability to dramatically increase throughput or range at reasonable energy efficiency. Networks with a long, single-hop between nodes require a significant increase in power to increase throughput or range. Multi-hop networks at current operating frequencies offer improvements in energy efficiency or range, but with severe limits on throughput. We show that the throughput limitations of multi-hop networks with a shared channel can be overcome in a high absorption regime. Underwater acoustic absorption is a well behaved function of frequency, and extremely high absorptions can be accessed at useful frequencies so that network range and capacity may be dramatically improved in an affordable manner.