Abstract

Toxic gas leakage that leads to equipment damage,
environmental effects, and injuries to humans is
the key concern in large-scale industries, particularly
in petrochemical plants. Industrial wireless sensor
networks (IWSNs) are specially designed for industrial
applications with improved efficiency, and remote
sensing for toxic gas leakage. Sleep scheduling is
a common approach in IWSNs to overcome the
network lifetime problem due to energy constrained
nodes. In this article, we propose a sleep scheduling
scheme that ensures a coverage degree requirement
based on the dangerous levels of the toxic gas
leakage area, while maintaining global network connectivity
with minimal awake nodes. Unlike the previous
sleep scheduling algorithm, for example, the
connected k-neighborhood (CKN)-based approach
that wakes up the sleep nodes over the entire sensing
field by increasing the k-value, our proposed
scheme dynamically wakes up the sleep nodes only
in the particular toxic gas leakage area. Simulation
results show that our proposed scheme outperforms
the CKN-based sleep scheduling scheme with the
same required coverage degree for the toxic gas
leakage area. In addition, the proposed scheme
considers multiple hazardous zones with various
coverage degree requirements. We show that at the
expense of a slight extra message overhead, energy
consumption in terms of totally awake nodes over
the entire sensing field is reduced compared to the
other approaches, while maintaining network connectivity