A demonstration of absorption controlled isolation for underwater networks

Isolation is important in communication networks. Absorption has been proposed as a means to provide improved isolation in underwater acoustic networks. In underwater acoustic systems, absorption is a strong function of frequency, so absorption, and hence isolation, can be selected through choice of carrier frequency. The use of absorption to provide isolation, while well developed in theory, has not previously been practically demonstrated. We have developed a test methodology and equipment to demonstrate the variation in isolation at a range of operating frequencies in both fresh and salt water. We have demonstrated that isolation is indeed controllable in practical systems through choice of carrier frequency.