A Comparative Analysis of Application Layer Protocols Within an Industrial Internet of Things Monitoring System

The Internet of Things (IoT) involves a large number of devices communicating information to each other for a number of use cases such as a monitoring systems for leakages within a pneumatic system. A critical decision when designing such a system is the selection of an appropriate application layer protocol from the plethora of options that are available. Many studies have been done to facilitate this decision, but in this paper it is argued that the results obtained by such studies may have limited applicability to an industrial scenario. Once this argument is established, the paper expands on the experimental setup designed to rectify the methodological errors present in previous studies, reports the obtained results, and highlights notable discrepancies between them and the results reported in previous studies. Based on the obtained results, it is suggested that when lower transfer times are a priority, the Message queuing Telemetry Transport (MQTT) protocol with a quality of service (QoS) level of 0 ought to be used, while Constrained Application Protocol (CoAP) with non-confirmable messages may be the better choice in scenarios with constrained bandwidth requirements.