Enabling Long-Range Underwater Backscatter via Van Atta Acoustic Networks

Abstract

We present the design, implementation, and evaluation of Van Atta Acoustic Backscat­ter (VAB), a technology that enables long-range, ultra-low-power networking in un­derwater environments. At the core of VAB is a novel, scalable underwater backscatter architecture that bridges recent advances in RF backscatter (Van Atta architectures) with ultra-low-power underwater acoustic networks. Our design introduces multiple innovations across the networking stack, which enable it to overcome unique chal­lenges that arise from the electro-mechanical properties of underwater backscatter and the challenging nature of low-power underwater acoustic channels. We imple­mented our design in an end-to-end system, and evaluated it in over 1,500 real-world experimental trials in a river and the ocean. Our evaluation demonstrates that VAB achieves a communication range that exceeds 300m in round trip backscatter across orientations (at BER of 10-3). We compared our design head-to-head with past state-­of-the-art systems, demonstrating a 15x improvement in communication range at the same throughput and power. By realizing hundreds of meters of range in underwater backscatter, this paper presents the first practical system capable of coastal monitor­ing applications. Finally, our evaluation represents the first experimental validation of underwater backscatter in the ocean.