A Unified Method to Design Bridges for OPC UA PubSub Networks in the Industrial IoT

Specification part 14 of the Open Platform Communication Unified Architecture (OPC UA) standard provides five different profiles to implement the publish-subscribe messaging pattern. The specification is also called OPC UA PubSub, and its profiles are called PubSub profiles. Two devices deployed with the same PubSub profile can exchange and collaborate; however, two devices deployed with two different PubSub profiles are unable to communicate. It is a limit for the Industry Internet of Things, a complex environment where there would be heterogeneous devices and networks. One approach to overcoming this issue is to use a bridge for the devices deployed with different PubSub profiles. In this sense, this paper provides a unified method to design bridges for OPC UA PubSub networks. The proof-of-concept experiment, also presented in this paper, is a use case of bridging PubSub broker-less and broker-based networks.