One challenge associated with the Industrial Internet of Things (IIoT) is a clear agreement on its definition. Some claim an IoT device is any one that can connect to another using Internet protocol (IP), which explains the enormous number of IoT-enabled devices claimed in most market forecasts. They agree that compound annual growth rates (CAGR) for IoT approach 20% per year. However, as with many sectors relying on semiconductors, supply chain issues reveal constraints on adoption of IoT and IIoT.
Some constraints include disagreements about how to aggregate and gather signals, so they can be used. No official international standard exists. Currently, we have both ends of a connection, where sensors send IP packets and cloud services collect/store the data. However, the challenge continues to be in the middle, getting data from points A to B.
As previously stated here, without a common language (protocol), one set of packets can’t be differentiated from another in a useful way. The leading technology in this space is quickly becoming message queuing telemetry transport (MQTT) due to its light technical requirements and low overhead. MQTT has become the de facto standard for the cloud-based SCADA market when bandwidth is a serious constraint.
Sparkplug B, a specification that defines how data is sent and received, is frequently paired with MQTT. Both standards are being developed and maintained by the Eclipse Foundation (eclipse.org), which aims to provide a scalable and business-friendly environment for open-source software collaboration and innovation. The organization is also working to have its documents adopted as ISO standards.
Meanwhile, the most common method for getting from points A to B via IoT is Wi-Fi. However, Wi-Fi is generally only good for relatively short distances to either access point(s). From there, messages are aggregated onto an alternate carrier, perhaps with some intelligence to reduce required bandwidth.
Several surveys about IoT connectivity that include other short distance carriers such as Bluetooth report they aren’t feasible for the longer distances typically required of IIoT. Even though IoT surveys indicate that Wi-Fi and Bluetooth make up about half the connectivity market for IIoT, the real players are cellular—including 5G permutations—and low power wide area networks (LPWAN). Low earth orbit (LEO) satellites are a potential dark horse in the race.
Key factors to consider when selecting an IIoT long-distance solution are price and reliability. When available, cellular has coverage, particularly for IIoT devices that tend to be stationary, but come with the costs of services and associated supporting infrastructure that cellular players provide. LPWAN costs less but relies more on the organization using the network for support. LPWAN also has several competing standards, particularly LoRaWAN and Sigfox. LEO systems are a blend of cellular and LPWAN with a combination of support such as cellular.
One issue that could become a factor in the IoT/IIoT space that also compounds the supply chain issue is the pending “chip source dispute” between China and the “five eyes” countries (U.S., U.K., Canada, Australia and New Zealand), which maintain a signals intelligence alliance and monitor electronic communications. Based on my experience with international standards, China, as documented in its five-year plan, wants to be a leader in IIoT, which includes providing of many of the chipsets used in IoT devices. Both sides in this discussion don’t want to use the other’s chipsets for fear of backdoors and cybersecurity risks.
Maybe we’re making this more difficult than necessary. There are a lot of automation professionals familiar with SCADA technology, including selecting network technology, protocols and cybersecurity. Of course, they’re also familiar with integrating potential IIoT signal types, while also supporting geographically distributed signals across large areas, which sure sounds a lot like SCADA to me.
