A layered IoT architecture for greenhouse monitoring and remote control

Abstract

Wireless Sensor Networks have been often used in the context of Greenhouse architectures. In this paper, an architecture is proposed for two Greenhouses based on Networked Control Systems. This architecture is IoT-based and built on top of switched Ethernet and Wi-Fi. Some sensors in the proposed architecture require a one-second real-time deadline. Riverbed simulations prove that there is zero packet loss and no over-delayed packets. An important contribution of this work is the design of a channel allocation scheme that prevents interference in this relatively large Greenhouse system. Another contribution of this work is the introduction of fault tolerance at the controller level. If one controller fails in one of the Greenhouses, the other controller automatically takes over the entire operation of the two-Greenhouse system. Riverbed simulations again show that this fault-tolerant system does not suffer any packet loss or over-delayed packets. Continuous Time Markov Chains are then developed to calculate the reliability as well as the steady state availability of the two-Greenhouse system. The Coverage parameter is taken into account. Finally, a case study is presented to quantitatively assess the advantage of fault tolerance in terms of downtime reduction; this is expected to be attractive especially in developing countries.