The Intelligent Edge (Part 4)
The Intelligent Edge (Part 4)
This interview focuses on the challenges facing the Industrial Internet, including what goes into managing resources, particularly in a wireless environment.
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The Internet of Things has changed the consumer world in ways no one ever imagined. By placing intelligence in the IoT network, a “Thing” can do whatever we want it to do. Now, industrial companies are seeking to take advantage of this edge-deployed intelligence in order to maximize profits, improve safety, and streamline operations. In addition to the challenges IoT technology has had to overcome — such as cybersecurity, scalability, and interoperability – Industrial IoT (IIoT) must also focus on reliability, ruggedness, and more.
In the fourth installment of “The Intelligent Edge,” we spoke with Helen Xi, a senior firmware engineer at FreeWave who specializes in high-speed wireless LAN performance, to talk about the use of broadband in the IIoT, as well as FreeWave’s industrial Wi-Fi platform, the WavePro.
FreeWave: Can you talk a little bit about the WavePro platform and where it fits into what you work on at FreeWave?
Helen Xi: In our company, the radios mostly operate in the narrowband frequencies, however, WavePro is a broadband Wi-Fi system. It’s important for us to have this Wi-Fi system because nowadays there are so many Wi-Fi clients. It’s on every mobile phone, in every laptop, in every household. It’s everywhere. You can’t avoid it. When we have this Wi-Fi product, we can provide a whole communication system to customers. It’s easier for us to integrate them together to make sure they work from our Wi-Fi system to our narrowband radios. Our WavePro product has many features. If you compare it with the industry competitors, they have multiple products and models that meet customers’ specific needs. If you want to provide a long-distance point-to-point link and you buy this model, and you want their system to provide Wi-Fi local coverage, then you must buy another model. WavePro integrates all these features together in a single product, and we can do long-distance point-to-point link, local Wi-Fi coverage, and mesh. It can have different clients while providing a backhaul communications in a remote area.
FreeWave: Walking back a little bit on some of what you just talked about, one of the things that we’ve been discussing is the transition from traditional RF technology into technology that requires higher bandwidth to transmit bigger data packets in real time and run analytics at the Edge. With WavePro, what I’m wondering is when you talk to clients, what is their number-one priority with this technology? Are they trying to update existing systems or are they wanting to implement entirely new systems? And how important is the broadband aspect?
Helen Xi: I think both. Let’s say they want to upgrade an older system. Let me give you an example: nowadays because there are so many Wi-Fi clients, Wi-Fi chips are so well-known, and more sensors have Wi-Fi client chips inside them. If we put our WavePro in the field, it can work as an access point (AP) to talk to these sensors. By the way, our product is an outdoor unit. It’s waterproof IP67. IP67 means you can immerse it underneath water. It has the same industrial-temperature range as our other narrowband radios. It goes from minus-40 up to 70 Celsius. It also has surge protectors from lightning. So, you can safely put it outdoors. If you buy a home Wi-Fi router, say from Netgear, you probably do not want to put it outside.
FreeWave: And why is that element important?
Helen Xi: Because a lot of our customers use it outdoors. For example, in North Dakota, it’s very cold. It can be minus-20 Celsius. I think you can imagine what happens to your iPhone during winter when you go skiing – it goes dead. Our radios don’t do that. You put it outdoors, on the oil-gas fields where it goes from winter to summer – as cold as North Dakota, as hot as Texas in the deserts – and it’s working well. That’s why the temperature requirement is important.
FreeWave: When you’re talking about application examples, where else are you seeing this technology deployed?
Helen Xi: It can be used in many areas of the Industrial IoT. For example, we have a utility company that uses WavePros to control large quantities of air conditioners on the roof of two apartment buildings. Each air conditioner has a 2.4GHz Wi-Fi chip in it. They all connect to WavePros on 2.4GHz. One WavePro (we call it “master”) is connected to the utility company’s network. The other three WavePros (we call “slave”) connect to the master WavePro on 5GHz. When the utility company needs to send command to air conditions, it first goes to the master WavePro; the master WavePro passes on its 5GHz to the other slave WavePros; then, the slave WavePros transmit on 2.4GHz to each air conditioner.
FreeWave: What do you envision being the trend of the future with regard to Industrial IoT communications? Is it all headed toward broadband? Or do you think that there will still be a balance between that and cellular and RF?
Helen Xi: This is a very good question. I believe it will be a combination. I want to elaborate why I think narrowband is still very important where people seem to only be talking about gigabits. Wireless as a resource is very valuable – every Hz (hertz) is valuable. When you are using a frequency band at this location at this instant, other people cannot use it. You are noise to other people. Plus, not every Hz is free to use. In IoT, we’re mostly using an unlicensed band that you don’t need to pay a fee to the FCC to use as long as you follow rules. There are only certain bands you can use for free. Only use what you need. If you don’t need that much wireless resources, don’t use that wide band and leave it for your future growth, even if it’s on your own field.
A customer compared WavePro against a competitor’s product: “This product gives 60Mbps and yours is 40Mbps.” I looked at the settings and found they were on “Auto Channel” using 40MHz and we were using 20MHz. Think about the channel efficiency, bps/Hz, then ours was better.
Let’s go back to your question on the IoT — why I think this can’t be all broadband. It’s because wireless resources are limited and valuable. The FCC limits what is allowed for unlicensed use. If everybody uses broadband for everything, it’ll be very crowded very quickly.
Let me give an example of being crowded. Imagine you’re in an airport overseas where you don’t have cellular data service (or it is very expensive) and you want to use Wi-Fi. There are so many people are using the Wi-Fi, your speed is very slow.
That explains why wireless resources are valuable. In the Wi-Fi system – I don’t know if people all realize this or not – but communication parties share the same frequency channel. Here is an analogy: when I speak, you can’t speak; before I speak, I have to listen to make sure others are not speaking, then I can speak. This is similar to how Wi-Fi works. People in the same conversation share the same frequency channel. At one instant, only one party can talk.
Of course, in the airport, you can set multiple channels. If you use 2.4 GHz, you can have three channels that are usable. If you use 5 GHz Wi-Fi system, you can set over 20 channels people can use (different countries have different rules, 20 is for US). In Wi-Fi world, you can also set different sizes of channels – 20, 40, 80 MHz. But lots of the times in a downtown or busy area, if you use as wide as 80 MHz channel, you also open your door for noise. You feel you can transmit more because your channel is wider, but at the same time, you get more noise. There are tradeoffs.
There is another important reason we need to use narrowband. With narrowband, your total power consumption is lower (considering energy per Hz). The narrowband’s radio board size can be smaller and lighter. So, all these things are tradeoffs. Eventually, cost and effect become a real consideration.
FreeWave: It’s interesting because a lot of people don’t consider or think about how all of these wireless communication technologies, that are in the IoT and or connected systems, are actually built on limited wireless resources. There’s kind of a limit to how many things can be talking to each other and how they can accomplish that.
Helen Xi: There is another important communication concept that people might ignore. In the communication world, we transfer data like we transfer products in the real world – there is necessary overhead in every communication layer. In Wi-Fi communications, there are three main layers that we generally care about: PHY, MAC, and TCP (or other layer-4 protocols). Every layer has its own management bits that help to transmit data successfully. When users look at the throughput, they only care about the final useful data. For example, if you want to transmit a photo across a wireless network, the photo file has to be modulated, queued for timeslots to transmit, protected and acknowledged. An analogy would be you need to ship a printed photo. It needs to be handed over to a shipping company, loaded on the correct truck, given a route and packaged well. Users only care about the final photo; all the other work is overhead but necessary. That’s why when your network indicates a 100Mbps connection, you do not have a 100Mbps TCP throughput. This “100 Mbps” indicates the fastest transmission speed at the physical layer. Your TCP throughput is only the useful stuff for end users, the “photo” for example.
The different levels and needs of IIoT technology mean that there isn’t a one-size-fits-all solution for communication solutions. However, industrial Wi-Fi has the potential to create a great avenue for organizations looking to maximize data transmission and connectivity. As Helen pointed out, this will require a different perspective on the usage of broadband: companies will need to treat those bands as a limited resource and use them as needed instead of cramming them with devices. She recommends narrowband as a solution, along with a combination of cellular and RF where possible. There are many nuances and considerations to take into account when deciding which solution is the best fit, but most companies should be thinking about the needs of the actual application and not just speed.
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