On Consistent Neighborhood Views in Wireless Sensor Networks

Wireless sensor networks (WSNs) are characterized by localized interactions. Indeed, several WSN algorithms and protocols work in a decentralized fashion by coordinating nodes within the wireless communication range, e.g., localization algorithms and MAC protocols. Nevertheless, most often these mechanisms do not address faults that may affect the way wireless neighborhoods are recognized by nodes, e.g., as in the case of data corruption. As the operation of these mechanisms is rooted in the use of topology information, these faults may be a significant detriment to correct and efficient system operation. In this paper, we argue that the above issues are particular instances of a general problem of consistent neighborhood view. We present three increasingly weaker specifications of the problem. Next, we prove the impossibility of solving the two stronger specifications, and provide an algorithm to solve the weakest specification. In addition, we implement our algorithm in a commonly used WSN network stack, and assess its performance both in simulation and in a real-world testbed. The results show that, when possible, our mechanisms efficiently solve the problem of consistent neighborhood view, providing higher-level mechanisms with a re-usable building block to leverage off.