Abstract
The expectations for sensor networks are growing. One of the most important issues in sensor networks is to evaluate the fault tolerance and built technology to improve it, because sensor nodes are prone to fail and have limited power capacity. So far, research on the fault tolerance has focused on battery exhaustion. Since placement affects whether there are nodes that can sense and routes to the base station, placement of sensor nodes is also important. However, there has been little research on the placement of sensor nodes and all of it is based on deterministic placement, which is not realistic when many sensor nodes are placed in a large area. In such a situation, stochastic placement is needed. Therefore, this paper evaluates the tolerance against both random failure and battery exhaustion from the viewpoint of stochastic node placement.