Fault Tolerance for Access Point Failures in Smart Greenhouse Networked Control Systems

Greenhouses offer the ability to cultivate various crops in what would otherwise be harsh and unfavorable environments. Networked Control Systems (NCSs) can be utilized within greenhouses, to monitor and control various metrics, such as temperature, humidity, and soil moisture. While the utilization of wireless sensors offers a high degree of flexibility, it adds the risk of Access Point (AP) failure. This paper investigates the issue of AP failure in a Greenhouse NCS and proposes a fault-tolerant model. Single as well as double AP failures are considered. All scenarios in the fault-tolerant model are simulated using the Riverbed Modeler and system performance is evaluated in terms of the Packet Loss Rate (PLR). It is shown that, for all possible AP failures in the fault model, the proposed fault-tolerant architecture succeeds in meeting system requirements.