Stabilizing Reconfiguration in Wireless Sensor Networks

• Main Authors: Bapat,Sandip, Arora,Anish
• Format: Report
• Language: English
• Subjects: 10012; detectors; fault tolerance; stabilization; wireless sensor networks

A commonly desired feature of large-scale, multi-hop, wireless sensor networks is the ability to reconfigure them after deployment. This reconfiguration could be as simple as a single parameter change or as complex as replacement of the entire program. Several protocols have been proposed to enable reconfiguration in wireless sensor networks, many of which use version numbers to distinguish new configurations from old ones. Due to physical constraints, these version numbers are bounded in size and use wraparound arithmetic to handle rollover. While this simple scheme works well in the common case, problems may occur if the nodes in the network have arbitrary version numbers. In this paper, we identify a serious version management problem in existing reconfiguration protocols. We analyze potential causes of this problem and its effects on the quality and lifetime of the network. Through extensive simulations and experiments, we demonstrate the significant likelihood of this problem occurring in practice and measure its impact. Finally, we provide a solution to this problem using a novel approach to stabilization which we call Human-In-The-Loop stabilization. Our stabilizing reconfiguration protocol uses local detectors and correctors that can detect version inconsistencies and prevent their propagation in a timely and efficient manner, while ultimately allowing the human operator to restore the network to the correct configuration.