Monitoring Diffusible Event with Point-Sensing Sensors

In existing work of wireless sensor networks, sensing models, including disk sensing model and directional sensing model, agree that a sensor can cover a specified region around the sensor. In fact, certain type of sensors can only sense the place where they locate. Based on the observation, this paper proposes the point sensing model, where the sensing range of a sensor is limited to a point which is its location. This paper models sensor networks using point sensing sensors to monitor diffusible events, and proposes a series of new concepts. The coverage is redefined as the overlapping of the sensor and the event. As the detecting sensor cannot determine the position where the event originates, then we propose an algorithm which utilizes multiple sensors to collaboratively determine the event cradleland.