An energy-efficient mechanism for self-monitoring Sensor Web

A Sensor Web is a network of spatially distributed sensor platforms, which is especially well suited for environmental monitoring. Although sensor nodes of a Sensor Web are critical devices that perform the monitoring work, the low-cost implementation of sensor nodes poses that they are subject to failures and permanent damage. A life-condition monitoring mechanism for sensor nodes is therefore required to ensure the function of a Sensor Web. This paper studies this sensor-node monitoring problem in the domain where in-network sensor nodes are self-monitoring, i.e., the status of each sensor node is monitored by another node. To be energy-efficient, a mechanism for implementing self-monitoring Sensor Webs should minimize the energy required. We propose a formal formulation of this problem and show that it can be solved by finding a minimum spanning tree of the graph constructed by in-network nodes. We provide some distributed algorithms in solving this problem. Simulations are conducted to study the performance of these algorithms.