Selective wakeup discipline for continuous object tracking in grid-based wireless sensor networks

A principal issue for wireless sensor networks is energy efficiency, which is necessary for prolonging applications to track continuous object, such as wild fire and poison gas. Selective wakeup approach is an effective way to save energy in such networks. However, most previous studies on selective wakeup schemes have concentrated on individual objects, such as intruders and tanks, and they cannot be applied for tracking continuous objects. This is because the continuous object is pretty flexible and dynamic due to its sensitiveness to surrounding natural effects so that movable area cannot be correctly estimated by the just spatiotemporal mechanism. Therefore, we propose a grid-based protocol for applying the efficient and accurate selective wakeup technique to tracking continuous objects. When an object is detected in some specific area which tightly surrounds the object, a pre-designated area where the target may move is activated to prepare the target without any complex calculations. Moreover, our protocol is simple and asynchronous, which makes it more suitable for wireless sensor networks.