Just how FAST is WiFi 6?
Linus Tech Tips
·Linus Tech Tips
·2019-05-06
·
1,793 words · ~8 min read
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Every once in a while, it feels like the stars just align perfectly for me.
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We were literally right in the middle of planning a Wi-Fi upgrade
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so that we could test the brand new Wi-Fi 6 capabilities of the Samsung Galaxy S10 series
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when our buds over at Cisco reached out to sponsor a video explaining the benefits of Wi-Fi 6.
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So we were like, uh, so yeah, you know that beastly new access point?
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Well, I think to really show off the benefit of Wi-Fi 6, we'd probably need a couple of those.
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That okay? Yeah? So done?
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So today's video then is all about what Wi-Fi 6 is, why you might care,
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and when you can expect widespread adoption.
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And we're also going to take it for a test drive with the shiny new Galaxy S10+.
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So strap in, because this is going to be fun.
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While our APs are being installed,
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let's talk about what is the same.
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Physically, the hardware for Wi-Fi 6 is actually quite similar.
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So on the client side, cell phone and other device manufacturers can continue to lean on the antenna design experience
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that they've gained from previous generations of Wi-Fi,
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with even the battery consumption of new Wi-Fi 6 chipsets
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only expected to increase during times of continuous high-speed data transfer.
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And even then, that's only because the data rate is higher.
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So nothing really changes there.
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As for the deployment, that's basically the same.
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Remember your best practices for AP positioning, run your Ethernet,
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and wire everything up to your network switch.
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Because Wi-Fi 6 is backwards compatible, any legacy clients on the network won't even know the difference.
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Now, let's talk about what is different, which is basically everything, starting with even the name.
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Wi-Fi is undergoing a much-needed and
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surprisingly sensible rebranding right now, from 802.11 something something,
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for those curious, by the way, this generation was going to be called 802.11ax,
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to simple numbered generations.
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So AC becomes 5, N becomes 4, and so on and so forth,
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with these little icons that are designed to inform consumers which generation is supported by both their client
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and the AP that they happen to be connected to.
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Next up is the deployment.
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Yeah, okay, it's not quite the same.
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So Wi-Fi 6 handles more clients and more cluttered environments better.
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So you might not actually need as many APs, which is nice,
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but watch out, because you're not going to be saving a buck here.
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Each of those access points could be handling multiple
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gigabits of data per second across literally hundreds of clients.
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So your commodity gigabit PoE suite,
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your commodity gigabit PoE switch isn't going to cut it anymore.
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So we're moving to this Meraki MS355-24x2.
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It's 24 multi-gigabit ports, could actually be fully loaded with MR55 access points,
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thanks to its beefy 740 watt power supply,
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and this thing is rated at up to 640 gigabit per second of switching capacity.
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And all of that is important.
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Because even though it's rated at a mere
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39% faster throughput,
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so about 600 megabit per second versus 433 on a single 80 megahertz 5 gigahertz channel,
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thanks to packing more data into each payload,
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Wi-Fi 6 has some truly game-changing features when it comes to multi-client access
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that are going to result in far higher overall data rates and less waiting.
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So first of all, access points can be configured
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with up to an 8x8 antenna configuration.
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So that is 8 for sending and 8 for receiving.
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And on top of that, Wi-Fi 6 supports up to 8 concurrent downlink streams with multi-user MIMO.
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That is a huge increase over the 4 concurrent downlink streams that was supported with Wi-Fi 5.
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So this widening of the highway, so to speak,
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is a big part of what's going to make Gen 6 so critical to making Wi-Fi usable in large venues.
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Like sports arenas and crowded concert halls.
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But it's not even close to the entire picture.
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The next huge innovation for large-scale deployments was actually borrowed from cellular networks.
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With Wi-Fi 6, the band or the frequency range that would have made up a traditional channel
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can be split using a technique called Orthogonal Frequency Division Multiple Access
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or OFDMA.
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So, you know how one of the best
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pro tips for anyone living in an apartment is to use a scanner to see what channels your neighbors are on and then
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manually switch over to a different one? Well, forget about it.
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OFDMA allows each band, be it 20, 40, or all the way up to 160 megahertz, to be split up into multiple chunks as many as 78 sub-channels and each one of those can be allocated to a separate client.
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Now obviously, to make all of this work, the access point
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needs to get a little bit smarter.
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Fortunately, it did. With Wi-Fi 6, an AP can negotiate what are called
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Deterministic Connections, allowing it to exercise a great deal of control over the connected clients and how they're allowed to behave.
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So first, a client gets dynamically assigned however many channels or sub-channels can be spared at that moment.
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Then, things get even crazier. Each client gets a schedule for when it's allowed to transmit
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and receive data.
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Now, hold on a second. I know that in the computing world,
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scheduling a data transmission usually means increased latency,
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which is one of the biggest issues with Wi-Fi today.
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But in practice, what this means is less collision mitigation overhead, which means that there's actually less waiting around.
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Think of it kind of like a perfectly executed zipper merge on the highway, so it will actually reduce latency.
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That means, yes friends, gaming online,
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gaming on Wi-Fi without legs bikes could actually be a thing with Wi-Fi 6. Go figure.
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Another fun feature of Deterministic Connections is that they can be used to save power.
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So, you know your connected smart light switch, your Amazon button, your asset tags, etc, etc, etc.
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Right now, they waste a ton of power constantly checking in with the network.
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Hey, you got anything for me? No? Okay. How about now? Got anything for me? No? Okay.
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Well, with scheduling,
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with gradual check-ins called target wake-up time, your devices can check in far less frequently,
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dramatically increasing their battery life.
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The coolest thing about Wi-Fi 6, though, is not the techy specs, as much as I personally get really amped on that stuff.
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Rather, it's the different experiences that it enables. Like, have you ever tried to stealthily have a video chat at the back of a lecture
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hall or
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upload a video to YouTube from a large event? It's a total mess. And I mean, even something as stupid as
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breaking for lunch during a conference can absolutely crush your mobile experience as
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everyone jumps on Facebook at exactly the same time.
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Well, thanks to everything I've talked about already, and actually a whole host of other new features,
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including better beamforming, spatial frequency reuse, and dynamic fragmentation, which makes better use of the available spectrum.
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Oh, man, actually, I forgot to mention that, too. Down the line,
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we're even getting more spectrum in the 5 to 6 gigahertz range.
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That's gonna be sweet. Anyway, the point is, with all of this new tech,
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this is not like an incremental,
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generational, evolutionary improvement. And you could even argue that this is the biggest
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fundamental change that we've seen yet for Wi-Fi. And I, for one, am stoked.
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But,
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there's always a but, isn't there? The one buzzkill today is that while Wi-Fi 6 is backwards compatible,
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you're gonna have to wait a little while
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longer for the kick-ass experience that I've talked about here, because the promises of Wi-Fi 6 can only be fully realized
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once client devices with support for these new features start to overtake their legacy counterparts.
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Now, the good news is that at least they're already showing up.
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So, all that's left in this video, then, is to take our S10 Plus for a quick test drive. Now,
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one problem I have is that we don't have a couple hundred of these,
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so I'm not gonna be able to do that.
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I'm not gonna be able to do, like, a mega-client test or anything like that,
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but we can at least make sure that everything's working properly here in the office with a quick speed test.
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So, without further ado, let's see just how fast we can make this go.
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So, the first thing that I noticed, just connecting to our new access point, is that, remember those little icons
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I told you guys about? It's right there at the top of the phone.
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Wi-Fi 6, so you'll know that you're negotiating your link using the correct generation of the technology. So, that's pretty cool.
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Then, for us, remember, we just upgraded to 10 gigabit intranet, so as long as we can find a speed test server that can
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take the burn, then all we got to do is run a simple speed test here, and have a look at what kind of speeds that we can get.
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And I have never seen anything like this.
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That upload speed.
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800 megabit per second. Guys, not only is this Wi-Fi, this is Wi-Fi on a mobile device.
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This is a 2x2 antenna.
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This is a 2x2 antenna configuration. That is real-world speeds of
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like 800. We're getting close to if I actually plugged a USB type-c dongle into my phone and plugged it into the wall.
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That's absolutely incredible. And like I said before, it is absolutely just the tip of the iceberg.
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So, thanks for watching guys. Thanks to Cisco for sponsoring this video.
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