Signal reflection-enabled geographical routing for underwater sensor networks

The 3-D nature of the underwater environment has made geographical-routing a popular choice in underwater acoustic sensor networks (UW-ASNs). A geographical (geo) routing protocol works by using the position information to find the best route from a source to a destination. These algorithms, often try to minimize the line-of-sight (LOS) Euclidean distance between hops, which is not always possible due to blocked LOS paths resulting in voids (or local minimum). Thus, traditional geo-routing algorithms typically employ a face routing recovery scheme that allows for back-tracking when blocked LOS links are encountered, which adds delay to the data delivery time. To overcome this, we propose a geo-routing scheme that does not depend on the LOS and utilize directional antennas to incorporate surface-reflected non-line-of-sight (NLOS) links in the routing process. Furthermore, the proposed algorithm is configured to optimize the route selection to achieve maximum network throughput. Simulation results are provided to validate the performance of the proposed algorithm.