Resilience against Shipping Noise and Interference in Low-Power Acoustic Underwater Communication

Underwater Wireless Sensor Networks (UWSNs) and micro Autonomous Underwater Vehicles ($\mu \mathbf{AUVs}$) enable diverse underwater monitoring and service applications; e.g., observation of water quality or identification of pollution sources. Reliable underwater communication for data transmission between sensors, $\mu\mathbf{AUVs}$ and base stations is required and typically acoustic. However, vessels and $\mu\mathbf{AUVs}$ produce noise, disturbing the acoustic data transmission. Additionally, in networks there is potentially a risk of packet interference. This paper discusses the resilience against noise and interference of low-power acoustic underwater modems in a network. We used the smartPORT Acoustic Underwater Modem (AHOI modem) to analyze signal processing and modulation schemes in a concrete case. The AHOI modem modem is a small, low-power and low-cost modem, which was developed for UWSNs and integration into $\mu\mathbf{AUVs}$. Based on our findings, we evaluate the resilience in simulations and through real-world experiments in a marina. In general, the results are useful to design and simulate low-power acoustic underwater communication.