Demo: Bi-static Scatter Underwater Acoustic Communications

Scatter radio achieves communication by reflection and requires low-cost and low-power radio frequency (RF) front-ends, however RF does not propagate more than a few centimeters through water. In this demo, we show the feasibility of near-zero power underwater communications using passive sensor/tags in a bistatic topology to communicate sensor data by means of acoustic reflections. We present a non-classic bi-static scatter communications architecture, where the carrier emitter is an acoustic wave generator detached from an acoustic receiver. We built a tag prototype that consumes less than 4 mW for communications and less than 0.5 mW in sleep mode. In the demo, we will demonstrate low communication rates of 100 bps at small distances inside a small 10 gallon fish tank.