Enabling Reliable and Network-Wide Wakeup in Wireless Sensor Networks
Abstract: Event-triggered wake-up, in which sensor nodes wake up to work in the presence of some pre-defined events, has been widely used in wireless sensor networks (WSNs) to save energy while still completing the tasks required. However, some recently emerged domain-specific WSN applications such as structural health monitoring (SHM) and volcano seismic tomography, have different requirements with regard to wake-up as compared to conventional WSN applications. In these domain-specific applications, the wake-up should be network-wide and nodes to be woken up are not limited to those close to event locations. In addition, the wake-up should be fast to capture enough information during generally short events and be reliable to avoid costly false-positive wake-ups. This problem has not been addressed in the literature. In this paper, we designed two types of wake-up units, based on which we propose a new chain-reaction wake-up mechanism to address this challenge. In this mechanism, we carefully select some nodes used to initiate the wake-up process, such that the wake-up delay is minimized under the false alarm constraint. We propose two greedy algorithms and a randomized one that leverages the solution to the classic Knapsack problem. The performance of the proposed wake-up mechanism is demonstrated through both simulation and experiments.