Design and prototyping of low-power wide area networks for critical infrastructure monitoring

Low-energy critical infrastructure monitoring (LECIM) networks is essential for the monitoring of infrastructure facilities in smart cities. One critical requirement of an LECIM network is its wide coverage of up to several kilometres by using a star topology instead of the tree or mesh networks. In meeting this requirement, this study develops a system with a transceiver of extremely high receiver sensitivity based on the IEEE 802.15.4k physical layer specifications. To reduce the energy consumption, the modulation schemes suitable for low complexity detection are chosen for the data transmission in the design. Also, an efficient parallel preamble and payload data detection are adopted at the access point of the proposed LECIM to acquire concurrent packets from respective nodes. Meanwhile, a data-aided dynamic timing adjustment scheme is proposed for data field detection to rapidly and adaptively synchronise to the long duration of data packet. Furthermore, a testbed is implemented using a software-defined radio to demonstrate the effectiveness of the proposed system design.