 So, we'll get started here in just a couple of minutes, but one of the questions I was asked, why did I do this particular presentation? And the answer is really quite simple. There's so many different versions of Wi-Fi out there. There's so many different addresses, so many different numbers and letters and everything else assigned to it that it was like, if I'm confused about what Wi-Fi is what, then somebody else probably is as well. So we will try to address those issues and make sure that everybody understands what versions mean what, especially when it comes to some of this new stuff, when they're saying, oh, it's going to be Wi-Fi 6. Well, wait a minute, Wi-Fi 6, how the hell does that relate to 802.11 whatever? And so, and then I found out there actually was a Wi-Fi 1, 2, 3, 4, and 5. And they never said anything about those. So we'll talk about those as well. But now they're talking about Wi-Fi 7, and it's like Wi-Fi 6 isn't even out yet. And they're already talking about Wi-Fi 7, and it's got its own goofy 802.11 BE assignment to it. So it's weird. They're rapidly running through the alphabet. They've already run through it once, and now they're at the AA something, you know, X-A-D-A-F, and they'll run through those, I guess, and we'll go to, well, they're already talking about BE is the next one, so go figure. All right, well, we are at time. So let's go ahead and get started here. My name is Mike Anderson, and I will, let's see, if I can get it to turn once there, right? There we go. That's my particulars. If you need to get ahold of me, feel free to reach out on LinkedIn and, of course, the website and email. I work for the PTR group. We're a consulting shop. We've been in the Linux business since about 2000. We were the first to put Linux in space. That was on Taxat 4 for the Navy. That was back in 2007, and now we do a lot of work with NASA, most of the space refueling mission, the new Restore L, where we're trying to refuel a low-Earth orbit satellite. We've got Linux on that platform as well. So it is a lot of experimentation with Linux over the years. We've used it for everything from bicycle shifters all the way to big robots in space. So lots of fun stuff. We are now a wholly-owned subsidiary of Huntington Ingalls Industries, which is better known as Newport News Naval Shipyard. So I am now owned by a shipbuilding company, of which I'm not quite sure exactly what that means to me. My 24-person company is now part of a 40,000-person company. I'm sure we're still having kind of selling shocks because the company that bought us originally did not tell us they were selling to somebody else. So that's the way it goes. So what we're going to talk about is we're going to talk about IEEE 802.11 and of course the Wi-Fi Alliance and how that factors into things. We'll do a quick history and try to clear up some of the naming confusion associated with Wi-Fi. As we go through, we'll discuss various topics like the frequencies that are being used, the modulation techniques, the data rates you can expect to get, and we'll finish up by talking a little bit about security and the future of where we believe Wi-Fi is actually headed. So the Wi-Fi Alliance, which is an industry consortium, they are responsible for a logo program, and that logo program then designates, if you see the logo, Wi-Fi Alliance, then you know that that device has been tested and is compatible with other devices that also have the logo. So it's a mechanism for being able to guarantee some interoperability between the individual manufacturers of components. As of 2019, they actually claimed that there's been over 60 billion devices shipped that support Wi-Fi. Now they claim the 20th anniversary of Wi-Fi is in 2019. We'll see in just a moment that that's not quite true, but we'll get to that in a bit. Now as the Wi-Fi Alliance continues to expand, if you want to basically sell compatible devices to Wi-Fi, you effectively have to become a member of the Wi-Fi Alliance. Now that's not of course cheap, but that's not my problem, I'm just a user of Wi-Fi, so I want to make sure that things are interoperable, therefore the logo program is a good thing. Now in the early years, the first Wi-Fi was actually 1997, so much for 20 years of Wi-Fi, that would have been two years ago, but that's okay, we'll kind of give them a break on that because the real first significant piece of Wi-Fi, which was the two megabit per second support for Wi-Fi, didn't come out until 1999. So we'll give them the 20 years on that one. One of the key things about the Wi-Fi world is that it's originally been targeted and continues to operate inside of the industrial, scientific and medical bands. So the 2.4 GHz ISM band is unique around the world in that it is the one band that exists in all countries. So when we talk about the 5 GHz band, we talk about the 1.2 GHz band, even the 900 MHz bands, those frequency ranges do not exist as open frequency ranges in all countries. So and it turns out that the U.S. restriction on the 2.4 GHz band is actually quite a bit smaller than what we would see in countries like Israel or Japan, where they have additional frequencies inside the 2.4 GHz band. So when we're buying a Wi-Fi device, we also have to take into account what region are we buying this device in and what region are we going to deploy the device in. Because we may in fact run afoul of various frequency allocations. If we're trying to run a Japanese radio here in the United States, their channel 1314 is outside of the U.S. allocation for the 2.4 GHz ISM band. So we could in fact run ourselves into trouble if we had the FCC really knocking on our doorstep. Now in 1999, they introduced 802.11A and this was the first use of the 5 GHz band. So the 5 GHz band understand that when we talk about frequencies, the higher the frequency, the less its ability to penetrate walls. So when we go from 2.4 GHz to 5 GHz, well we've effectively cut the distance that we can get out of the signal and we've cut its ability to penetrate walls and operate inside of buildings. So that does become a bit of a problem. Now one of the advantages, however, of the 5 GHz frequency for 802.11A was they added orthogonal frequency division multiplexing, OFDM. And OFDM has a distinct characteristic in that you can operate multiple radios in the same frequency spectrum, all of them using OFDM and they won't interfere with each other. So that's a huge win when you're trying to operate multiple access points or multiple SSIDs simultaneously. But with the 802.11A specification, they went from the 2 Mbps frequency, 2 Mbps data rates that we saw with the original 802.11 to 54 Mbps. Well that was a huge, excuse me, gigabits per second. Was that a gigabit? No, megabits per second, that's a typo. So it's megabits per second. And that was a huge jump in capability. At the same time, they then found that the original Wi-Fi had some serious problems. And those serious problems had to deal with interference. The original Wi-Fi frequencies happened to also sit where microwave ovens radiate. And there were also portable phones. Back in the day before cell phones, we actually had these things called portable phones. And they were wireless phones that would then operate with your landline, another unique concept these days. But it turned out that they could easily be interfered with. So if somebody was trying to use the internet and they were on their 802.11 Wi-Fi interface and then somebody decided they were going to microwave dinner, well you suddenly lost all connectivity to the internet as long as the microwave was running. Those problems were a significant issue with Wi-Fi. And that's why in 1999 they also brought down 802.11 B. 802.11 B was 11 megabits per second. It switched to a direct sequence spread spectrum option. And by going to spread spectrum, it basically bounced around inside the frequency bands in such a way that you didn't get any significant interference from microwave ovens and other devices that happened to be sitting in the 2.4 GHz band. So that was a real hop, a real jump in terms of capability that were basically things that existed just before the turn of the century. And I like saying it that way because it's like when you say, oh, this was the way we did it before the turn of the century. That makes it sound really old. Now in the aughts, in 2003 they introduced 802.11 G. And with 802.11 G, because of the problems they were running into with the original 802.11 specifications, they took the OFDM modulation technique from the 5 GHz band and moved it into the 2.4 GHz band. So that then gave us a 54 megabit per second frequency, a 54 megabit per second transmission rate, but with forward error correction. And with the forward error correction, of course, it made it much more reliable. But it also significantly cut the effective throughput on the device. So we were seeing an average of about 22 megabits per second in the 2.4 GHz band with 802.11 G. Because they're not one to leave well enough alone, the 802.11 frequency group, the TGMA task group, then took the specifications for 802.11 A, B, D, E, which never got deployed, G, H, and I, and rolled them all into one specification called 802.11 MA. Of course, they had no devices that actually spoke 802.11 MA. They were just doing that as a way of trying to reduce the amount of documentation that they had to have in order to keep track of all these individual variants. But then in 2009, they introduced 802.11 N, and within the unique characteristic of N was they introduced what they called multiple input, multiple output antennas. So they started going from the concept. If you look all the way back to G and earlier, there was one stream. And the data rate that you got was the data rate you could get on one stream. When they went to 802.11 N, they added multiple streams. And those streams could then be bonded together into a single data throughput. So when we looked at 802.11 N, we had antennas and devices that could operate in both the 2.4 GHz and the 5 GHz bands. In the case of 802.11 A, it was only 5 GHz, and 802.11 B was only 2.4 GHz. With 802.11 N, we had now both 2.4 and 5 GHz. And the data rates could range anywhere from a single stream at 54 megabits per second all the way up to multiple streams at 600 megabits per second. So 802.11 N was a huge jump in capability that everybody was very excited about. Well, unfortunately, that was still not fast enough. And as we start getting faster and faster, understand that at the time, Ethernet was about a gigabit per second. So they were trying to get the equivalent of a wireless gigabit Ethernet to delivered from an access point to a consumer. So in the 802.11 N amendment, they basically took that original standard and they switched from a 20 MHz or 40 MHz channel up to an 80 or even a 160 MHz channel. Now, when they went to the 80 and 160 MHz channels in the 5 GHz band, they also added additional spatial streams. So now we had up to 8 spatial streams as opposed to 8.11 Ns for spatial streams. They also switched the modulation technique. So QAM, QAM is a quadrature amplitude modulation signal. So in the case of 802.11 N, they were using 64 QAM, which is 64 bits, basically 64 symbols per cycle. When they went to 802.11 AC, that is 256 QAM. So they multiplied the number of symbols considerably and they also doubled the number of spatial streams. So if we take a look at some of the high-end implementations in the 80 MHz channel space, we had three spatial streams and 256 QAM. We would effectively see three separate 433 Mbps streams and when we combined them together through bonding, we were getting an equivalent of about 1.3 Gbps. So we managed to make that one gigabit number that they were trying to get to make it compatible or actually competitive against normal wired Ethernet. Now vendors have announced a special version of 802.11 AC called Wave 2. And in Wave 2, they go to 160 MHz channels. So again, they've doubled the size of the channel. And with 160 MHz channel and four spatial streams, and they add one more thing to that. And that is multi-user, multiple input, multiple output antennas. So this means if we take a look at a typical antenna right now, you've got one user, one antenna, they communicate with each other, then they have to switch to another user. In this case, with multiple user MIMO antennas, now I can run multiple users at the same time, all using the same four spatial streams at 160 MHz for an effective throughput of about 3.4 Gbps. Now in terms of the availability of Wave 2 devices, that hasn't really been made significantly available. You can get samples at this point, but they're still pretty expensive. And understand that if you get a Wave 2 access point, you still have to have a Wave 2-compatible client, otherwise you're not going to see the kinds of performance out of it. So in terms of being able to actually scale this thing up, it's a significant investment in terms of getting Wave 2 devices, especially when 802.11ac is now old. So when we talk about 802.11c with the use of multiple antennas, we get significant better performance out of it, but now we've got another problem coming on the horizon. One of the problems that came about was the introduction of another industry consortium called YGIG. Now the YGIG consortium did something else and they said, you know, our big problem is that the 2.4 GHz band is shared by Bluetooth and ZigBee and 802.154 and a whole bunch of other frequencies, a whole bunch of other techniques are all in use in the 2.4 GHz band. They also saw that the 5 GHz band is actually not all that wide and it actually has two separate sections of the 5 GHz band. So that made things even more complicated. So the YGIG industry consortium decided, well, let's throw all that out. We don't care about all of that. What we're going to do is we're going to jump right to 60 GHz. Now this is millimeter wave. Understand that 2.4 GHz is microwave frequencies. Anything above about, well, there's a magic number, but anything above 24 GHz is going to be millimeter wave and millimeter wave has the advantage that up in the 60 GHz band, there's a lot of bandwidth there. There's a lot of frequency space available, which means we can run extremely wide frequency bands. But as I said, the higher the frequency, the harder it is to penetrate walls. So 60 GHz is fantastic in terms of the throughput. However, it's not going to be able to get out of this room. As a matter of fact, it might not even be able to get to the back wall. So there are certain applications like set top box to TV sets that make a lot of sense for 60 GHz. But not all use cases are going to work terribly well with this particular model. Nonetheless, the Wi-Fi Alliance saw that this YGIG Alliance was basically trying to create a competitive standard. So the Wi-Fi Alliance didn't want that. So they bought the YGIG Alliance and made them part of the fold and they then took what they were doing as YGIG and gave it a new name. And it becomes 802.11 AD. 802.11 AD has a very high data rate. It's seven gigabits per second is the throughput on that. But it's only over very short distances, typically less than 10 meters. So inside this room, maybe it would work to the back corner, maybe not. But if it did work, you'd get incredible throughput out of it. So an interesting trade-off. Now, what's happened though is because most handsets like your cell phone and your tablet and your PC don't have 60 GHz radios in them, it meant that they're not compatible with the 802.11 AD specification. So what they've done is they've created dual-mode radios that have 802.11 AC for 2.4 GHz and 5 GHz on one side and 802.11 AD on the other side. So you can do 60 GHz if you've got a 60 GHz radio or you can use 2.4 and 5 GHz if you have normal radios. Okay, well, that's kind of cool. But a lot of that is assuming that sooner or later we're going to get handsets with 60 GHz frequencies in them, which is not necessarily a safe assumption. So another aspect of this, at the same time, there's another group of people out there that says, remember back when we switched over from analog television to digital TV, we then had all the frequencies that are associated with the VHF and UHF television frequencies, that became what's known as white space. So 802.11 AF is also known as super Wi-Fi or white-fi, where it basically implements a wide area, a wide local area network, a wireless local area network in the frequencies between 54 and 790 MHz. Now on the plus side, 54 to 790 MHz, those frequencies actually go very long distances. You can get potentially in the 54 MHz band, you can get hundreds of miles in the 54 MHz band. But in the way they defined 802.11 AF, basically you have to have access to a geographical database that tells you what other operators may in fact be licensed to operate in those frequencies. So the FCC opens up bids basically for a lot of these white space frequencies, and they've sold some of them. We've seen numbers like several billion dollars for buying the rights to certain parts of these frequency spectrum. So with 802.11 AF, you have to ask a regional database who has a legitimate license in this particular frequency range, and if you have someone that has a legitimate license, you have to basically release the frequencies periodically. So here in the United States, when you acquire one of these frequencies, you have access to it for 48 hours, and then you have to move to another frequency. In the EU, it's only two hours before you have to move to another frequency. So from a coordination perspective of how am I going to coordinate between the transmitter and the receiver, I have to do a handoff between the transmitter and the receiver to let the receiver know, hey, I'm getting ready to change frequencies, you need to follow me to what used to be the old VHF channel four. And then everything would move to VHF channel four, and you'd have that for another 48 hours, and then you'd have to move to channel six or whatever. So that becomes kind of complicated. But what they did was they took advantage of 8211AC's OFDM modulation technique, and they had channels that were in between that could either be six, seven, or eight megahertz wide. So using 256 quam and up to four channels bonded together, it meant that if I was using six and seven megahertz channels, I could do about 426 megabits per second. If I'm using an eight megahertz channel, I could get 568 megabits per second, but I could go extremely long distances with this. Now, ostensibly, they had a limit on here that said no more than a kilometer. But there's nothing about the frequency that limits that. And in fact, what they've done is they've introduced yet another standard, the 80222 standard. The 802.22 standard is a wireless regional area network, a metropolitan area network that has ranges up to 100 kilometers, and it coexists with 802.11 AF. So this is something to take advantage of the white space. If we were to look at the entire frequency spectrum from DC to daylight, it turns out there's not a lot of open spaces. It's either already allocated to some preexisting service, or it's allocated to the military. And the military isn't too keen on giving up their frequency spectrum. And obviously, there are other organizations like CB radios and ham radio operators and all these other people that are either licensed or have purchased a license for some of this frequency spectrum that they're not eager to give up their frequency spectrum, especially when it cost them a billion dollars to get access to the spectrum in the first place. Now, if you take a look at normal cellular communications, cellular communications today in the United States for 4G LTE is anywhere from 1.7 GHz up to 2.2 to 2.3 GHz. So it's just below the 2.4 GHz band. And when we talk about 5G and its interface to Wi-Fi, we'll actually find there's some other problems that come up because of that. We'll get to that in a moment. Now, unfortunately, if we were to take a look at a typical Wi-Fi radio, Wi-Fi radios are incredibly power hungry. So from an embedded systems perspective, trying to put a Wi-Fi radio on your embedded platform means you're going to burn through your battery in a very short order. So one of the other versions of Wi-Fi is called Wi-Fi Halo, otherwise known as 802.11AH. In 802.11AH, it's again one of these repeater modes where I have one frequency on one side and a different frequency on the other side of the radio. In this particular case, they're using the 900 MHz ISM band on one side of the radio, and they're going to 11AC on the other side of the radio. Now, what's the advantage of using the 900 MHz band? Well, it is, in fact, an ISM band. So it's an open frequency here in the United States. In the European market, they don't have the 900 MHz band. They have the 868 MHz band. So one of the problems for Wi-Fi Halo is that they can sell one radio in the United States, but they have to sell a different radio in European nations. And neither of those two frequencies are available in Asia. So this, of course, further complicates things, but the significant advantage of the 900 MHz band is its range. I can easily get a couple of kilometers out of 900 MHz with the right antenna. So this gives me the ability to have a reasonably good transmission rate and understand that for most Internet of Things devices, I don't need megabits per second. A few k bits per second is usually plenty fast enough. So in Halo, they had 26 channels of 100 kilobits each, and then it would go into the radio and pop out on the other side as 11 AC. So you could basically use the radio as an aggregation point of multiple sensors out in the field, aggregate them to the radio, and then the radio would spit them out as high-speed Wi-Fi on the other side or potentially go gigabit ethernet or whatever happened to be wired to the radio at the same time. This was kind of a cool approach, but it's one of these cases of it may have been too little, too late. In the Wi-Fi specifications, I mean, for the Wi-Fi Alliance, the Wi-Fi Alliance realizes that they're eating a lot of battery when they're using Wi-Fi. So they've been working very diligently to try and cut the power requirements for Wi-Fi. Wi-Fi Halo was meant to do two things, increase the range for Internet of Things devices and cut the power requirement for those Internet of Things devices by getting everything down in the 900 megahertz band. Well, if they can cut the power requirements for Wi-Fi across the board, then part of the argument for Wi-Fi Halo goes away. So even though there are radio units that are available, that is embedded modules that are available for Wi-Fi Halo, we haven't seen Wi-Fi Halo really hit the market any big way, and it could be one of these things. It's just too little, too late, and it'll just die on the vine. Now, the successor to 802.11ac is also known as Wi-Fi 6. This is 802.11ax. Now, 802.11ax ties OFDM, MuMemo, the multi-user, multiple in, multiple out antennas, but it goes from 256-QAM to 1024-QAM. So again, we've now just multiplied the number of symbols per signal time that we can get out of this particular type of modulation. It's backward compatible with 802.11abgn and ac, so you don't have to worry about older devices not being able to talk to it. And they've also implemented a new encryption standard called WPA3. Why did they call it Wi-Fi 6? Because quite frankly, all this 802.11acagab, whatever, is confusing as hell to the community. That is to the consumer. The consumer doesn't know what they just bought. Do I need an AC? You're telling me I need AX, but AX isn't commercially available. Well, it is sort of commercially available if I'm willing to spend $500 for a unit, but most consumers are not willing to throw away all their old equipment just so they can have this incredible performance. What kind of performance are we talking about here? Remember, it's about four times the throughput of AC. So we can actually see significantly faster performance out of this. And part of the argument is they could do it this way without needing millimeter wave radios, without needing 24 gigahertz or 60 gigahertz or any of these other special radios. They could do it with existing radio silicon. Now, beyond 802.11aX, we have 802.11aY, and the 60 gigahertz frequencies are just not going to go away. 802.11aY brings 60 gigahertz millimeter wave back as an extension to 802.11ad. And unfortunately, if you take a look at some of the other frequencies that this particular standard operates in, it overlaps with some of the 5G cellular technologies. So how this is going to play out, it's not entirely sure yet. But just so that they don't leave well enough alone, they've introduced 802.11be, which is the extremely high throughput that builds on top of 802.11aX for indoor usage using the 2.4, but they also now have an extension into 2.5, 5 gigahertz, and 6 gigahertz frequency bands. 6 gigahertz was a fairly small band, but they have enough range in there that for indoor use, it won't interfere with anybody else. So this is likely going to be standardized as Wi-Fi 7. And again, the idea is, let's give it a simple number for people to remember. We'll call it Wi-Fi 7. Everything's cool. Well, they added to the 802.11aX, they added this import of WPA3, so we'll come to that in a moment. Just for research capabilities, I kind of went back and I go, well, if they have a Wi-Fi 6, did they actually have a Wi-Fi 1, 2, 3, 3, 4, and 5? It actually turns out they did, but they never advertised it. So Wi-Fi 1 was 11b, Wi-Fi 5 was 11ac, and now Wi-Fi 6 is going to be 11aX, and Wi-Fi 7 will probably be 11be. All right. Wi-Fi mesh. Now, this is another aspect. It turns out that all the Wi-Fi mesh implementations that you have in your home today, because you can't get access to the far end of the house, and so you had to put a repeater in there, those are all proprietary. So you cannot mix and match. You can't take Googles and mix it with anybody else's. There is a standard called EasyMesh where they have a standard that's been specified, but none of the manufacturers have signed up to it. So even though they have a standard, and they could standardize so that all the radios are compatible with each other, at the moment there's no impetus for them to do that, because Google wants to be able to sell Google radios, and Asus wants to be able to sell Asus radios, and Apple wants to sell Apple radios, so you just have to buy radios from the same manufacturer. The Wi-Fi alliance does not see this as a problem, because it basically sells more radios. So whether or not we'll actually see anything that uses the certified EasyMesh standard as an open standard, it's hard to say at this point. Excuse me. All right. So to kind of wrap things up here, a quick word on security. Of course, when Wi-Fi first came out, it had this thing called wired equivalent privacy, and WEP came in both the 40-bit and 128-bit mode. The problem with the algorithm is that it reused initialization vectors. So if I sat there with Kismet or AircrackNG for more than about 10 minutes, I could break into your Wi-Fi system. And a lot of people did that. So they decided that WEP was bad, so they decided to replace that with a new version, a new encryption standard called WPA. But WPA had its own set of weaknesses, so they had to replace that quickly with WPA2. WPA2 is an enhanced WPA that added support for pre-shared keys, or PSK. It also had a whole bunch of enterprise class additions for CCMP and advanced encryption standard, AES. This is basically what we see today in all of the open Wi-Fi access points. So the one that we're running here for the Linux Foundation, the hotel Wi-Fi, the airport Wi-FIs, the Wi-FIs in Starbucks and things of that sort, they're all running WPA2. If they're running any encryption at all, they're running WPA2, and you just simply have to have access to the pre-shared key, like in our case Linux 1991, that pre-shared key then gets me into the interface. Now, one of the problems and one of the things they were trying to address with WPA3 was setting up a mechanism so that there would no longer be open Wi-Fi access points. So with WPA3, they would effectively do a handshake between your radio and the access point, and it would negotiate a pairwise key. It would look a lot like Diffie Hellman in the way that it would negotiate a secure channel, and then you would always be a secure channel into the device. They would have 128-bit personal mode and 192-bit enterprise mode for using this particular encryption technique. So it used the CSNA encryption suite and forward secrecy techniques, but unfortunately, even though it looked like it was a good idea, it was subject to the crack attack, and so there was a mechanism for breaking into WPA3 using this particular technique called the crack attack, and it found out that WPA3 wasn't as secure as they thought it was. So unfortunately, they found not only that problem, but they've also found other serious design flaws in WPA3. So in spite of the fact that it looked like a good idea, WPA3 is actually subject to a downgrade attack where I can actually tell it to fall back to WPA2 and leave the WPA2 channel open so I can get into the system. There was also some side channel attacks to be able to extract out the SSID. There was also, and the key out of that SSID, there were also another attack that could be used to brute force the password. So at this point in time, the security saga continues. We don't have a good solution yet, and everybody understands that we need to be able to effectively do away with open access points, but in order to do away with open access points, it then means I need to have enough CPU horsepower to be able to handle the encryption for potentially dozens of units that are all attached to one particular access point, where I'm pairwise negotiating that encryption. For 802.11 AX with WPA3, the minimum machines that we're seeing are 1.8 GHz quad core systems. So now the amount of heat that's being generated by these radios is becoming significant, not to mention the power consumption. So, our summary is that Wi-Fi by itself is a confusing mismatch of 802.11.something, and it's very difficult for the typical consumer to sort out which one is which. We know that now they're trying to make this a little bit simpler by rebranding this as Wi-Fi 6, and if everything has got Wi-Fi 6 and the little Wi-Fi 6 logo on it, we know it should be compatible, but at this point in time, the consumer is so hopelessly confused that it remains to be seen how many of them are actually going to plunk out another several hundred dollars for a new radio. Of course, some of the differences in the ISM bands in various countries also further complicate things. I can't run 900 MHz in Europe. I can't run 868 MHz in Asia. So, and then the 60 GHz bands, those are millimeter wave. That's a completely different kind of radio. It does not penetrate walls. Oh, and by the way, if you're thinking that 5G cellular is going to be your solution, understand that 5G cellular is in the 24 to 26 GHz bands. So you're going to have to have five times as many cell towers as you have now in order to support 5G. Fortunately, those cell towers come in the form of light poles. So major metropolitan areas are going, ooh, we're going to make a lot of money off of our light poles because I have power and enough altitude that I can actually run a 5G cellular. They'll have lots of 5G Pico cells in order to be able to support 5G, and it'll only work in cities. It won't work out in the hinterlands because the radio frequency just doesn't transmit that far. So 5G is probably not going to be your solution in spite of what all the telephone companies would like for you to believe. We will always have 4G at some level, at least for the foreseeable future, because that's the only way we're going to be able to service the outer reaches of the rural areas. We're not going to be able to do that with actual 5G. And don't believe that 5G evolution is 5G. It's not. It's 4G. They just put fast 4G, and they called it 5G evolution. So it's all marketing. It's all crazy. And unfortunately, we find ourselves in a circumstance where we really need to have greater frequency, we need to have greater range, which typically means lower frequencies, but there aren't very many lower frequencies to be had. WPA3 was supposed to make things better. Unfortunately, it's already been pwned. So we don't know what's going to happen with WPA3, assuming they will either fix WPA3 or they'll just simply move to WPA4, whatever the answer to that is. So stay tuned. You'll have to figure out how to set that up on your radios, on your home routers at some point in the future. All right. That's it for me. Any questions? Yeah. Well, and that's because 802.22 is trying to replace it. So 802.22 is going to be the white fi. It's going to be the metropolitan area transmission of Wi-Fi. There are examples that are running, but in terms of being able to have a shipable product, I haven't seen any yet. So it's a concept. It's out there. Manufacturers have radios. We have techniques for actually doing it, but now you have to have the will of the metropolitan area to actually set up radios like that. Understand that the metropolitan area radio system is really not a solution for delivering radio signals to the end user. It's to handle the last mile. So it gets me to your house or it gets me to the Starbucks, and then in the Starbucks, I'm going to have to go from 802.22 to 802.11. Oh, for a marine application. Yeah. Yeah. So in that circumstance, yes, there is a standard. There are radio modules available for it, but I've not seen any actual product shipping that uses it. Yeah, we'll talk about that later. Any other questions? Yeah. Is just marketing. Yep. Now, if you're in your house and there's no other radios nearby, then, and you live in Kansas somewhere, then you can probably actually get those kinds of speeds, but also understand that AX is going to be more focused on doing like set top box to TV kind of transmissions, fairly small range. And as a consequence, yes, it's really fast when you can get the connection, but it will start falling back. And that's why they say it's compatible with A, B, G, N, and AC. Well, it'll fall back to 256 quam or even back to 64 quam in order to be able to interoperate if it's in a really noisy environment. So most of it is smoking mirrors, frankly. Now, the question was, if I have an AC radio, if I have an AX radio, and I've got three users in the room, two of them using AC, one of them using AX, what's it going to do? Is it going to fall back to AC or is there going to be an AX and then ACs? Well, this is where the multi-user part of it comes in. So multi-user, multiple input, multiple output says that it will, in fact, have AC channels for those people that are using AC and an AX channel for those that are using AX. And it'll keep them separate. Yep. Yes. Yeah, so they have an aggressive sleep schedule for this. Understand that for the most part, when we're dealing with a radio, it's got a lot of time that's basically dead time. I mean, unless you're doing streaming from Netflix, there's a lot of dead space, a lot of dead time on the radio in the frequency band. So what they're trying to do by reducing, in order to reduce the power consumption, they're basically looking at all those things based on the speed of the connection. So if I've got an AC connection to an AX radio, that says I've got a lot of dead time. So I'm going to take that dead time and I'm going to put microsleeps inside of the system in order to shut the radio off during those times. The device that's actually running the radio is not really consuming all that much in terms of power. It's the transmitter that actually consumes most of the power. So if the transmission is going mostly outbound and you're not really transmitting, you're actually receiving, then you can also power it down. You can actually cut the power back. So this is one of these things that the manufacturers are going to have to get very aggressive in terms of their power consumption. Especially when you look at a typical AX system, which is going to be a 1.8 gigahertz quad core, this is going to be a fair amount of heat this thing is going to generate. And are you going to want an access point in your house with fans running on it? Probably not. So you're going to have to dump the heat somehow and that's another one of the reasons why they're getting very aggressive with the power management because they want to be able to keep the temperature of the CPU as cool as possible. So yeah, they're going to have to get really aggressive with that. And fortunately, in the case of Linux, we have the no hurts option. So we can actually then turn off the clocks and do interrupt reduction so that we can put it into sleep states for extended periods of time. And then obviously during sometimes, you know, some point in time in the middle of the night, for instance, from like midnight to eight o'clock in the morning, there may not be much traffic out there at all. So they can cut everything back to even 11g and see if anybody is communicating. And if somebody tries to communicate, then they can power up and be able to go to the faster speeds, but they don't have to sit there and work at AX speeds all the time. Yes. Ah, Bluetooth and Wi-Fi. So I've done a lot of work with Bluetooth mesh. And of course, Bluetooth sets in the same frequency spectrum as Wi-Fi. And they do interfere with each other if you don't allow the Wi-Fi to move between channels. So typically here in the United States, we have 11 channels, channel one through 11. And there is some overlap between those channels and the Bluetooth specification. However, the Bluetooth mechanism uses a completely different modulation technique. It uses Gaussian frequency shift keying, or there's another one, but neither one of them are OFDM. So we can actually have the radio set up on the Wi-Fi side using OFDM, and they won't be interfered with by either the BPSK or the GPSK, the Gaussian frequency shift keying. So they won't be interfered by those. The only thing that we would run into is if there was a broadband jamming that was going on. So I mean, if all of the Bluetooth radios, because they use frequency hopping as well, if all the Bluetooth radios suddenly woke up and started just transmitting without any secession, that will basically block off a big chunk of the 2.4 gigahertz band, and that would force our Wi-Fi's down into the lower frequencies in that band. But are they going to interfere with each other? We haven't seen much interference at this point between those two spectrums, but we do know that we can't just basically take the entire 2.4 gigahertz band. Also, if you look at Bluetooth mesh, there are three advertising bands that are used in the 2.4 gigahertz spectrum for Bluetooth, and Bluetooth mesh uses all three of those advertising bands, and that's how they can get two megabits per second out of Bluetooth mesh. Bluetooth mesh is really targeted more at lighting and locks on doors and things of that sort. So it's a smart city kind of, or smart building kind of protocol. Not really made for Wi-Fi, I mean not made for IP traffic. It's really just made for device to device communications. So I don't see much in the way of interference between those two spectrums. It is of course possible, but with OFDM able to sort itself out between them and Gaussian frequency shift keying, I don't see you're going to see much in the way of problems with that. Anything else? That's it. Thank you very much.