A study of the Seastar underwater acoustic Local Area Network concept

Abstract

This research considers the "Seastar" concept of an underwater local-area network (LAN) having a central node and multiple peripheral nodes. The concept of operation for the Seastar LAN involves the delivery of large volumes of digital information from the peripheral nodes through direct acoustic communication links to a sophisticated central node for assimilation (e.g., beamforming, fusion). For a design range of 500 meters, link budget analysis in combination with parametric analysis evaluates physical-layer parameters including optimum carrier frequency, spectral bandwidth, modulation techniques, achievable bit rate, and energy budget. Performance data obtained from a prototype Seastar LAN constructed from existing acoustic modems guided the creation of a Seastar numerical simulation. Monte Carlo simulation studies examine the relative merits of networking strategies such as TDMA polling and token-based TDMA. Seastar is shown to meet the anticipated requirements for undersea LAN applications such as sensor networks, undersea vehicle swarms, and dive teams.