Towards a factory-of-things: Channel modeling and deployment assessment in PetroEcuador Esmeraldas oil refinery

Industry 4.0 and industrial Internet of Things (iIoT) trends are pushing towards the transformation of factories to provide more flexible production systems through the use of wireless networks. Technologies enabling the "Factory-of-Things" (FoT) paradigm allow the safe deployment of wireless field devices in industrial plants thanks to their low-battery usage that makes the maintenance cycle quite low, and highly reliable. The widespread adoption of these technologies should be paired with tools for predeployment network design and prediction of the wireless link quality to mimic the planning procedures applied to conventional industrial wired equipment. In factory sites, the strength of the radio signals is impaired by frequency, spatial and time-domain fading that influence the wireless link stability. In this paper, based on an extensive measurement campaign performed inside an active oil refinery, we propose and validate a novel channel model tailored for industrial wireless networks operating over 2.4 GHz and supporting a time-slotted channel hopping (TSCH) policy. Post-layout network performance verification has been finally carried out based on a WirelessHART industry standard system deployed in selected sites.