Why IIoT Connectivity Choices Are Harder Than They Look
In those cases companies aren’t worried about connectivity, he said — they’re worried about the cost of physically connecting new things together. “They’re assuming the connectivity protocol situation is going to be handled because they’re thinking about other things.”
With so many assumptions floating around, it can be hard for a company and a vendor to get on the same page with connectivity. Comstock’s advice: “Focus on the use cases. If you want two-way data communication, make sure you’re getting that and not something else.”
Looking at the Big Picture
Another challenge is a tendency for IIoT developers to look just at individual pieces and not at the full stack, which Joshi said is just asking for trouble. As part of his work with the IIC, he and his colleagues tried to streamline the process by drilling down in to the areas that seem to trip companies up the most: the transport and framework layers, to draw from the Industrial Internet Consortium’s connectivity stack model. The transport layer is simply a way of exchanging information that is created and interpreted by humans, Joshi said. “The framework layer is responsible for providing the exchange of structured information. The framework layer looks at an industrial IoT system and asks how to build concepts that exist but aren’t formalized.”
Thinking through these pieces of the stack will lead to more questions, Joshi warned. Companies need to both define the data objects and the way they’re addressing them. Will the life cycle be forever or finite? What about governance, exceptions, security or unmet delivery requirements?
This is also the moment in time companies need to think about the future. It’s easy to just assume that what works for a proof of concept IoT trial will be what works in the future, said Zach Shelby, vice president of developers, IoT services group at ARM. “It’s important to think what you’re going to need to design in to the devices early on,” Shelby said. “Companies need to take into account what kind of management infrastructure will be necessary as you move from hundreds to thousands to millions of devices. This isn’t the exciting stuff but you need to spend time on that and not just on the features (of the project).”
So after every other connectivity box has been checked, the final step, Thanigai said, is to count on everything changing, and then plan for it. “Leaving hooks in the system and designing with products that allow you to grow and meet evolving needs is important,” he said. “This could be as simple as ensuring every single node has the capability to update firmware/software over the air, preventing recurring maintenance costs or costly services fees or as complex as designing in products that support multiple frequency bands to avoid future congestion.”
It’s a lot to consider, but if misery loves company, you’re far from alone, and help is available. The IIC Connectivity Framework includes comprehensive assessment templates for protocols such as DDS, OPC UA, oneM2M, HTTP, CoAP,and MQTT, as well as detailed guidance on every step of the way.