Latency evaluation for MQTT and WebSocket Protocols: an Industry 4.0 perspective

Internet of things (IoT) is a trend which consists of providing connectivity for many consumer devices. Consequently, a considerable number of applications never seen before is emerging to make daily lifestyle more practical and connected through sharing, storing and processing personal data. When applied to industry, the same technologies can cause a real revolution in the manner how the information is treated. The value of the processed data is increasing fast and point to the fourth industrial revolution, or industry 4.0. This paper evaluates the performance of two ICT (Information and Communication Technology) protocols coming from the consumer world with an enormous potential to be used by industry. Experiments were performed to measure the round trip time using MQTT (Message Queuing Telemetry Transport) and WebSocket protocols with the exchange of data between one server in Italy and another in Brazil. The results can be analyzed for each possible application and different network paths. The average latency samples using each of the protocols were similar, defining the payload size of the requests, but changing according to the way.