Event localization in Underwater Wireless Sensor Systems using Monitoring Courses

We propose m-courses (Monitoring Courses), a novel solution to localize events in an underwater wireless sensor network. These networks consists of surface gateways and relay nodes. GPS can localize the position of surface gateways which can then distribute their locations through the network using acoustic modems. Relay nodes are deployed to remain static but due to water currents, floating, and the untethered nature of the nodes, they often suffer from frequent drifting which can result in a deployed network suffering link failures. In this work, we developed a novel concept of an underwater alarming system using a cyclic graph model. In the event of link failure, a series of alarm packets are broadcast in the network. These alarms are then captured by the underwater Monitoring Courses (mcourses), which can also be used to assure network connectivity and identify node faults. m-courses also allow the network to localize events and identify network issues at a local level before forwarding results upwards to a Surface Gateway nodes. This reduces communication overhead and allows for distributed management of nodes in a mobile network. Our results show that M-Course routing reduces the number of sends required to report an event to a Surface Gateway by up to 80% when compared to a naı̈ve routing implementation.