Utilizing Automatic Underwater Vehicles to Prolong the Lifetime of Underwater Sensor Networks

Consisting of sensors and vehicles, Underwater Sensor Networks (UWSNs) are deployed to perform collaborative monitoring tasks over a given region, such as water quality monitoring, mining equipment monitoring, oceanographic data collection, pollution surveillance, etc. However, comparing with terrestrial wireless sensor networks, it is more crucial to prolong network lifetime for UWSNs since the varying characteristics of the underwater environment and superior difficulty of underwater device maintenance. In this paper we present a three- dimensional hemisphere model for UWSNs and prove that the improvement in network lifetime by utilizing one Automatic Underwater Vehicle (AUV) is upper bounded by a factor of eight and the AUV only needs to stay within a two hop radius of the sink. We further propose an underwater aggregation routing algorithm UARA to prolong lifetime by utilizing one AUV. Finally, we perform extensive simulations to validate our conclusions.