Using Directional Antenna for Continuous Moving Object Tracking in WSN with Uncovered Holes

As a distinguished target monitoring system, wire- less sensor networks have spawned great advances. Most existing work concentrates on improving the accuracy and energy saving in a fully covered area by making full use of omnidirectional antenna. In reality, however, due to the death of sensors caused by harsh environment or energy depletion, the target may enter into a hole that is not covered by sensors. On the other hand, representative researches on boundary detection do not take target tracking into consideration. To address this issue, we introduce the idea of applying directional antenna to accomplish mobile target tracking in WSN with uncovered holes. We propose a collaborative signaling protocol to achieve the goal of continuous target tracking with low-energy-consumption. Simulation results have shown that the proposed approach can realize the real- time detection of moving object when it runs into and out of the hole, and at the same time, consume much less energy than the omnidirectional antenna based methods.