Adaptive surveillance in sensor network querying

The reduction of power consumption during the deployment and operation of sensor networks has commonly been recognized as a key challenge. At the operation level, many proposals have been put forth to reduce the number of sensor nodes being active at any point in time. Through selective querying and adaptive fidelity, only a small percentage of the nodes can be used while maintaining an acceptable level of accuracy. In most of these approaches, the exact percentage of nodes being queried is specified before hand. In practice, a smaller percentage is sufficient when the environment being monitored by the sensor network is quiescent, whereas a larger percentage is required to keep up with a rapidly evolving situation. In this paper, we propose a set of metrics that we use to assess the level of activity in the environment being monitored and a set of triggers based on these metrics to increase or decrease the percentage of nodes being queried depending on the level of activity measured. This approach is validated through Matlab simulations.