Towards Integrating MQTT with Time-Sensitive Networking

While the MQTT protocol is widely adopted in IoT applications, its usage for Industrial IoT is prevented by the lack of support for time-critical transmissions. For this reason, recent work has proposed the Prioritized MQTT (PrioMQTT) protocol, i.e., an MQTT extension that introduces message prioritization and schedules messages according to their priority, which reflects their temporal constraints. PrioMQTT succeeds in reducing the latencies of time-critical messages, but it cannot guarantee bounded delays, as the message priorities are not used by the underlying network level. For this reason, this work explores the integration of PrioMQTT with the Time-Sensitive Networking family of standards, in particular with the IEEE 802.1Q-2022, to handle multiple flows with diverse real-time requirements. The work also presents a preliminary experimental assessment on commercial-off-the-shelf devices.