Bringing deterministic industrial networking to the W3C web of things with TSN and OPC UA

IoT is often associated with low-power wireless, where best-effort communication is sufficient for many of its applications. Yet, in particular in Industrial IoT, strict quality of service (QoS) guarantees are required to enable deterministic real-time applications. Hence, wired communications are still predominant here, with Ethernet having become the main media for the industrial fieldbuses such as PROFINET, EtherCAT, or the emerging Field-Level Communications (FLC) of OPC UA. With the addition of Time-Sensitive Networking (TSN), an IEEE standards family for deterministic networking over Ethernet, Information Technology (IT) and Operational Technology (OT) can converge even at the shopfloor, as TSN-enabled Ethernet allows for several traffic types to co-exist in the same network. This paper proposes an extension to the W3C Web of Things (WoT) for semantics-enabled connectivity, which allows to cover application QoS requirements and network configuration within the W3C WoT abstractions. We contribute a QoS vocabulary for the W3C WoT Thing Description as well as design and open-source implementation of protocol bindings for OPC UA and NETCONF. Moreover, we discuss the challenges and pitfalls when designing new protocol bindings for W3C WoT.