Differentiated Surveillance for Static and Random Mobile Sensor Networks

The utility of a wireless sensor network derives primarily from the sensing data it gathers. Therefore, a critical issue for wireless sensor networks is to efficiently provide sensing coverage. This paper proposes a scheme, enhanced differentiated surveillance (EDS), to maintain the required sensing coverage by establishing working schedules of sensors for the purpose of energy saving. In EDS, each sensor generates its working schedule in a distributive manner with only one message exchanged among neighboring sensors. The required coverage is continuously guaranteed when every sensor schedules on/off sensing states according to its working schedule. Compared to the existing coverage maintenance schemes, EDS exhibits the beneficial features of minimum communication overhead, fast convergence, load balancing, and an efficient battery discharge pattern. Integrated with a neighbor discovery protocol, EDS is applied to random mobile sensor networks, where sensors randomly roam and cannot control their movements. While there has been much research effort on coverage maintenance by utilizing mobile sensors that can automatically move, coverage maintenance in random mobile sensor networks has not been addressed in the literature. Simulation results establish EDS as an effective coverage maintenance scheme for static and random mobile sensor networks.