Jamming-resistant multi-path routing for reliable intruder detection in underwater networks

In this paper, we discuss the performance of multi-path routing techniques in underwater acoustic networks applied to an intruder detection scenario. We assume that a network of submarine sensors is deployed close to a surveilled harbor, with the task to detect outbound surface boats. The communications take place in the 4 to 8 kHz band, in order to favor long-haul transmissions. This band is highly affected by the noise originating from the boat propellers. Therefore, we resort to jamming-resilient techniques such as multi-path transmissions. The latter is accomplished by restricted flooding, and by an adaptive form of source routing as an alternative. Our results show that the inherent redundancy of multi-path routing offers an effective shield against excessive packet losses in the presence of strong jamming. This increases the probability that data packets containing detection information are promptly delivered to the desired sinks, with respect to the performance of static, single-path routing. In particular, restricted flooding achieves the best delivery ratio at the price of a very high number of generated replicas, whereas adaptive source routing trades off a lower delivery ratio for a lower overhead.