Constructing event-driven partial barriers with resilience in wireless mobile sensor networks

A barrier-coverage in wireless mobile sensor networks (WMSN) has attracted lots of interests recently. It is highly desirable to consider a barrier-coverage that can detect any moving objects between multiple sides in an event-driven environment. In this paper, we introduce a new architecture of barrier, event-driven partial barrier, which is able to monitor any movements of objects in the event-driven environment. Also, resilient event-driven partial barrier is introduced to consider the case that the constructed barriers collapsed due to failures of some sensors consisting of those barriers. Then, we define two different problems formally. One is to minimize the number of sensors to generate complete event-driven partial barrier. Another is to minimize a total movement distance of sensors such that resilient event-driven partial barrier is formed to recover from sensor failures without any new addition of sensors. To solve the first problem, we propose two approaches, Greedy-Shared-Barrier and Greedy-Shared-Sensor, which create the complete event-driven partial barrier with possible minimum number of sensors. For the second problem, the proposed schemes, Uncovered-Sensor-Movement and Verified-Sensor-Movement guarantee a recovery of defective barriers with possible minimum total movement distance of sensors. Then, we analyze their relative performances through extensive simulations with various scenarios and also provide the complexity analysis of the proposed schemes.