Upper Bounds on Path Exposure in EH-WSNs with Variable Transmission Ranges

In this paper, we consider WSNs where nodes harvest solar energy for sustainable operation. We use a probabilistic graph model that associates a probability distribution with each node to model the random variability of a node's transmission range. In its basic form, the graph uses a 3-state node model that associates a probability distribution representing the likelihood that a node is either in a full power, reduced power, or failed state. Using this model, we tackle a problem, called path exposure with transmission range uncertainty (EXPO-RU) to analyze the exposure of a given path that we want to monitor against unauthorized traversal. The problem calls for quantifying the ability of an EH-WSN to jointly detect and report a traversal along the given path. To assess the reliability of an EH-WSN, we develop an algorithm for computing upper bounds on exact solutions, and present numerical results to analyze its performance.