Scheduling of Sensing Activity in Wireless Sensor Networks

Focus in this work is on the efficient use of energy for sensing. In particular, we are concerned with energy efficient algorithms for scheduling the sensing activity of sensor nodes. By scheduling the sensing activity we mean when to activate a sensor node for sensing and when to keep it idle (sleep mode). The novel approach we adopt in this work to achieve efficient scheduling of sensing activity is an information coverage approach, rather than the widely adopted physical coverage approach. In the physical coverage approach, a point is said to be covered by a sensor node if that point lies within the physical coverage range (or the sensing radius) of that sensor, which is the maximum distance between the sensor and the point up to which the sensor can sense with acceptable accuracy. Information coverage, on the other hand, exploits cooperation among multiple sensors to accurately sense a point even if that point falls outside the physical coverage range of all the sensors. In this work, we address the question of how to schedule the activity of various sensor nodes in the network to enhance network lifetime using information coverage.