This article is part of the Wireless Wish List series on industrial wireless networks. View the rest of the series here.
Far from being limited to process automation and control, wireless is making gains on all manufacturing and business fronts, just as it's taken over many consumer and mainstream applications. However, just like all forms of networking, wireless is still driven by its users and their innovations and requirements. And, despite its gains in all these areas, common-sense considerations and studies are still needed to determine what each user, application and site needs.
“OEMs want to make their devices smart and connected, often motivated by field service productivity and flexibility gains. They want connectivity with field assets, such as distributed solar generation, without a big investment in backhaul networking. And they want end-to-end solutions that integrate into their existing business processes and applications,“ says Mike Fahrion, CTO at MultiTech Systems Inc.. “Wireless technology has matured to the point where it can be integrated into most any application with rapid adoption where there is a high field service requirement. Pest control, medical sharps disposal units and even paper shredders are becoming smart, connected products.”
In the commercial and enterprise spaces, Fahrion reports that MultiTech is seeing three wireless technologies becoming standard:
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Wi-Fi for smart spaces like campuses, stadiums and oil and gas plants using it to extend the reach and mobility of Ethernet, but focused on networking of IT type assets, not mission-critical processes;
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Long-range wide area network (LoRaWAN) is becoming the norm for wireless sensor networks. LoRaWAN has a mile or better range, sensing nodes can be battery powered lasting five to ten years when configured to report-by-exception; and
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Private cellular networks using 4G and 5G provide high data throughput, low latency and mission-critical reliability bringing the benefits of wireless connectivity to applications that previously required wired connections.
“Privately managed LTE cellular is hosted by the user instead of a carrier. It’s totally private and managed, and lets users deploy only the devices they want, including managing their own bandwidth,” explains Fahrion. “For example, due to COVID-19, schools are giving out Chromebook laptops, and putting private cellular antennas on the school's roof, which lets local students log in for remote learning, even if they don’t have Wi-Fi at home. The advancement of standards based wireless technologies i displacing older, proprietary radio frequency (RF) wireless. The shift is to standards-based wireless drives down cost and provides users interoperability.”
While he agrees that full site surveys haven’t gone away, Fahrion adds fewer being done because users can put in wireless devices and simply validate it to see if it works. “LoRaWAN has remarkable receive sensitivity and operates at 900 MHz bands. Its high link budget makes it easy to pick up a good signal, even without line of sight, so they often get by without a site survey” says Fahrion.
Despite these advances and the fact it’s easier to use, Fahrion reports that users still have to think through how they’re going to use wireless. In wired solutions, we tended to send a lot of extra data because there were few consequences. “Wireless applications often imply battery power so we should think differently about the cost of data. Do you need to report every minute, every 15 minutes, or just when values change?,” asks Fahrion. “People are transitioning to wireless without shifting their mental paradigms, so they’re often paying for more than they need, both in power and bandwidth. Many users don’t need a report every 100 milliseconds, so they should only send a message when a threshold is reached, such as going over 100 °C, which uses a lot less battery power. They also need to decide on a format to get their information into real-life values.”
Even though LoRaWAN’s physical and network layers are common, its sensor data payload hasn’t been standardized yet, so configure or code systems to decode payloads from different devices. “This is one part of LoRaWAN that’s still messy,” says Fahrion. “Some vertically focused application groups, such as smart metering are driving more standardization to include data payloads.”
Fahrion concludes many users are mixing and matching wireless technologies based on the needs of their applications. “Some users are putting Bluetooth beacons on tools,” he says. "This can to indicate proximity to a receiver and battery status, then they’re adding LoRaWAN bridges to send their tags from tools up to a database.”
