The Alliance of SDN and MQTT for the Web of Industrial Things

The modern vision of "smarter"factory processes requires the adoption of Industrial Internet of Things (IIoT) ecosystems, where the large scale use of sensors, actuators, and connected devices enable a high amount of heterogeneous data gathering and sending to data centers for analysis and monitoring purposes. However, the foundation of the Web of Industrial Things (WoIT) faces open issues due to the constraints imposed by the involved devices, the technological heterogeneity, and the complex interactions and, hence, communications patterns. Toward this paradigm, a general framework inspired by the software defined networking (SDN) principle have been here proposed, in order to jointly optimize the application requirements by minimizing end-to-end delay and, thus, prolonging the lifetime of the IIoT ecosystem. This article derives a general SDN based architecture to handle data flows in order to support industrial applications that extend the basic publish-and-subscribe scheme. Specifically, the MQTT-SN standard have been considered, since it represents a solution suited for WoIT in the presence of resources constrained devices. The proposed integrated solution has been validated in practical scenarios, pointing out remarkable performance w.r.t. the end-to-end message delivery latency, always with a limited overhead.