Design of a low-cost, underwater acoustic modem for short-range sensor networks

A fundamental impediment to the use of dense underwater sensor networks is an inexpensive acoustic modem. Commercial underwater modems that do exist were designed for sparse, long range, applications rather than for small, dense, sensor nets. Thus, we are building an underwater acoustic modem starting with the most critical component from a cost perspective - the transducer. The design substitutes a commercial transducer with a homemade transducer using cheap piezo-ceramic material and builds the rest of the modem's components around the properties of the transducer to extract as much performance as possible. This paper presents the design considerations, implementation details, and initial experimental results of our modem.