Underwater wireless sensor networks (UWSNs) have been developed for a set of underwater applications, including the resource exploration, pollution monitoring, tactical surveillance, and so on. However, the complexity and diversity of the underwater environment differentiate it significantly from the terrestrial environment. In particular, the coverage requirements (i.e., coverage degrees and coverage probabilities) at different regions probably differ underwater. Nevertheless, little effort has been made so far on the topology control of UWSNs given the diverse coverage requirements. To this end, this article proposes two algorithms for the diverse coverage problem in UWSNs: (1) Traversal Algorithm for Diverse Coverage (TADC), which adjusts the sensing radii of nodes successively, that is, at each round only one node alters its sensing radius, and (2) Radius Increment Algorithm for Diverse Coverage (RIADC), which sets the sensing radii of nodes incrementally, that is, at each round multiple nodes may increase their sensing radii simultaneously. The performances of TADC and RIADC are analyzed through mathematical analysis and simulations. The results reveal that both TADC and RIADC can achieve the diverse coverage while minimizing the energy consumption. Moreover, TADC and RIADC perform nicely in obtaining optimal sensing radii and reducing message complexity, respectively. Such merits further indicate that TADC and RIADC are suitable for small-scale and large-scale UWSNs, respectively.
['Linfeng Liu', 'Jingli Du', 'Ye Liu']
Topology Control for Diverse Coverage in Underwater Wireless Sensor Networks