Optimal sleep scheduling with transmission range assignment in application-specific wireless sensor networks

To extend the functional lifetime of battery-operated Wireless Sensor Networks (WSNs), stringent sleep scheduling strategies with communication duty cycles running at sub-1% range are expected to be adopted. Although ultra-low communication duty cycles can cast a detrimental impact on sensing coverage and network connectivity, its effects can be mitigated with adaptive sleep scheduling, node deployment redundancy and multipath routing within the mesh WSN topology. Prior research on this issue had led to the proposal of a new design paradigm called Sense-Sleep Tree (SS-Tree). The SS-Tree aims to harmonise the various engineering issues and provides a method to increase the monitoring coverage and the operational lifetime of mesh-based WSNs engaged in wide-area event-driven surveillance applications. This paper further expands and refines the SS-Tree approach by incorporating practical design considerations such as transmission range assignment, duty cycling and sensing coverage. This approach can achieve higher energy efficiency and satisfy various application requirements during WSN network planning and predeployment phase.