With the progression of Industry 4.0 and the advents of Smart Manufacturing initiatives, not only has WiFi become more important on the manufacturing floor, but so have multiple forms of wireless communications. For those of you who are not familiar with Industry 4.0, it is a reference to the fourth industrial revolution taking place right now with smart manufacturing and automation. It is about technology integration into the manufacturing process and creating a smarter, faster, safer, and more efficient manufacturing environment.
Various types of wireless communication are already in place for many non-critical services in industrial and manufacturing facilities. Much of this is what qualifies as IIoT (Industrial Internet of Things) devices and sensors. Examples would include remote tank level sensors, vibration sensors and environmental measuring devices. Many of these use Zigbee or BLE (Bluetooth Low Energy) to create redundant, self-healing multipath mesh networks. They are not exactly high in overall throughput, but they provide very reliable connections. All of these provide information that is important but are not necessarily instrumental to the manufacturing process at any given site.
Yet another option that is breaking loose is private cellular. Operating in the 3GHz spectrum (and some others) it offers great stability due to cellular protocols and plays well with standard WiFi. For devices that cannot connect in that frequency, private cellular can be used for reliable backhaul for WiFi access points to help ease the structured cabling growing pains that are associated with WiFi deployments.
More and more, the desire for some kind of wireless integration into the industrial environment is becoming prevalent, adding to the overall Cyber-Physical Systems. Now you may be asking yourself, what is a Cyber-Physical System? That is a good question, I am glad you asked!
NIST defines Cyber-Physical Systems (CPS) as systems that are comprised of interacting digital, analog, physical, and human components engineered for function through integrated physics and logic. In essence, it is a system in which a real-world physical mechanism is controlled or monitored by computer-based algorithms. This means that any ICS network that deals with PLCs/DCS/SCADA controls is a Cyber-Physical System (not to be confused with Skynet from Cyberdyne Systems).
So where does wireless integration fit in if engineers are skeptical about deploying it for mission critical systems?
In walks WiFi 6 in all its splendor. Swaggering to and fro, it attempts to wow everyone with all of its marketing hype, shining bright like a diamond. Looking over at us with a sly grin as if to say, “Sup bro, check me out”.
But is the new proposed standard (I say proposed because as of this writing, it has not been approved by IEEE yet, though it is expected to be later this year) worth all the noise being made. Let’s take a look at the quick and dirty list of changes 802.11ax is bringing to the table:
- Reportedly, an approximate 30% increase in tx/rx speeds with the use of 1024 QAM
- That is fine, however I have yet to see any real world WiFi deployment get anywhere near the maximum theoretical speeds touted by various vendors for its predecessor 802.11ac, now known as WiFi 5, so I am not expecting to see multi-gigabit throughput. If you are, then please email me as I have some beach front property in Arizona I would like to sell to you.
- Lower connection latency
- More simultaneously deliverable data
- Improved power efficiency
- Introduction of OFDMA (Orthogonal Frequency Division Multiple Access) for WiFi
- This could very well be the game changer as it will introduce the stability and interference mitigation abilities that have been in use by Cellular/LTE for years
- It should reduce latency and increase network efficiency
- Extends the capabilities of Multi-User Multi-Input/Multi-Output (MU-MIMO)
All of the glitz and glamor aside, these sound like some solid improvements that could really move WiFi farther forward in the realm of production environments. So, the question then becomes, whose first? Who will foot the bill and be the sacrificial guinea pig that the rest of us can study and rip apart for all of the should of, could of, would of, and what if arguments?
Interestingly enough, some big names stepped up to put the initial iteration of WiFi 6 through its paces in an actual industrial manufacturing production facility in the UK.
In December of 2019, several members of the Wireless Broadband Alliance including Cisco, iBwave, Broadcom and Intel worked with Mettis Aerospace at their West Midlands factory. (For the record, Mettis Aerospace designs and manufactures precision forged and machined components to companies such as Boeing, Airbus and Rolls-Royce.) This is the first time that any group has come together to test out new wireless standards in a heavy manufacturing environment for validation.
iBwave performed the site surveys needed for the deployment while Cisco provided eleven Catalyst 9100 access points. Cisco and Mettis worked together using the results of the surveys to configure, optimize and implement the wireless network on the factory floor. Multiple mobile devices such as smartphones, laptops, tablets, and webcams all using either Broadcom or Intel WiFi 6 chipsets were used to perform a variety of tests, such as:
- Uploads of very large files over WiFi
- Augmented reality testing of machinery
- Roaming, latency and persistent connectivity during Wi-Fi video calling using smartphones
- 4k streaming from a webcam mounted on machinery within the factory
- 4k streaming from a laptop
All of this was going on in a heavy industrial area of the plant. Metal everywhere, thick dust in the air and who knows what kind of non-WiFi based interference being produced from presses and other heavy forge machinery. From the WBA’s press release (linked below):
“Speeds of 700 Mbps using 80 MHz channels were achieved during the trial and low latency applications, like video calling and video streaming, performed well with the average latency being less than 6ms and the maximum observed latency was 11ms.”
All of that going on and the recorded latency averaged 6ms or less. That is seriously impressive to this WiFi guy. If we disregard all of the other tested achievements of 802.11ax and just focus on the stability and the very low latency of this soon to be standard, I believe it would be enough to venture into critical communications of an ICS network. Even with peaking at 11ms latency, WiFi 6 would be well within the tolerance values of EtherNet/IP or PROFINET.
Other ideas come to mind as well, like wireless HMI displays. The flexibility of having a reliable HMI wherever you want to put it with the only restrictions being space and power would be incredible. The sheer number of wireless sensors that could be used is staggering. One thing to remember is that this trial was phase one. It will be interesting what phase two trials will look like.
While WiFi 5 (802.11ac) offered a great deal to users in the public and private sectors, it really did not promise anything special for ICS and other industrial networks. I think WiFI 6 will be a major turning point in wireless connectivity on the manufacturing floor. Let’s see how it goes and find out if I am right or wrong.
Want to know more about WiFi 6? TechRepublic has a great WiFi 6 Cheat Sheet that can be downloaded for free (though it does want an email address and whatnot, so use your moms if you don’t want to use your own) https://www.techrepublic.com/resource-library/downloads/wi-fi-6-802-11ax-a-cheat-sheet-free-pdf/
Other articles about the Mattis WiFi 6 trials:
Wifi-6 goes toe-to-toe with 5G claims
WIRELESS BROADBAND ALLIANCE MEMBERS SUCCESSFULLY COMPLETE FIRST PHASE Wi-Fi 6 INDUSTRY 4.0 TRIALS WITH METTIS AEROSPACE
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