WiFi Explained – b/g/n/AC/AX 6 6E & WiFi 7 + Mesh + MU-MIMO + More!

With the introduction of WiFi 7, WiFi has never been more complicated. MIMO, QAM, Multi-RU Puncturing, AC, AX, 6, 6E, 7, Mesh… There’s a lot to understand and I really wouldn’t blame you for getting lost in the mess, but hopefully after watching this video you’ll have some idea of what all that mess means, and which WiFi version is best for you. Let me clear the naming schemes up first. WiFi, as defined by the IEEE (the institute of electrical and electronic engineers), is the standard number 802.11. Much like German DIN standards all have numbers, or British BS standards, WiFi is standard code 802.11. The different versions of WiFi are one or two letters tacked onto the end of that number, so 802.11n, or 802.11ac. Yes, IEEE went to the Windows school of naming things, because here’s the order. B, a, g, n, ac, ax and be. Great, right? The number is the generation, so for all intents and purposes, WiFi 4 – that’s N – is the oldest version you’ll need to know about. They threw a spanner in the works with WiFi 6 and 6E, because they are both still 802.11ax, and AC isn’t much better with their Wave 1 and Wave 2 devices… I know, it’s already a mess, but that’s standards organisations for you. Long story short, both the suffix name, like AC, AX, or BE, and the generation number, like WiFi 5, WiFi 6E and WiFi 7 describe the same thing, which version of WiFi a device can use. The good news is that WiFi is backwards compatible – generally anyway – so a WiFi 5 device can still connect to a WiFi 7 router, and vice versa, so the only real difference between the versions to you the end user is speed and featureset, not outright compatibility. 

So, what makes WiFi 5 different from WiFi 7? Well let me walk you through each version, starting with 4. That’s from 2009, and was the first to introduce both the standard 2.4GHz and 5GHz frequencies, although it was often split access point names – like there’d be Router and Router_5 names to connect to (those are called SSIDs), although later versions generally refined that. Version 4 had either 20 MHz or a double-wide 40 MHz channels – although I should explain the difference between the frequency and the channel, since both are frequencies. The way WiFi works is by frequency modulation – like FM radio. Let’s say it’s exactly 2.4GHz – that’s 2,400 MHz. Now just transmitting at exactly 2.4GHz isn’t going to get you very far, so what you do is slightly vary the frequency, in this case 10MHz either side of that 2,400 MHz. By changing the frequency ever so slightly, you can encode data. The wider the channel, the more data you can encode at once, hence why N had the option to switch to using two 20MHz bands in a combined 40MHz mode for faster data transfer. There’s also one extra encoding feature that you should at least know in name – QAM, or Quadrature Amplitude Modulation. Basically this is how much data can be encoded per pulse, the higher the number, the more data. Gen 4 had a max of 64 QAM. The last feature you need to know about is MIMO, or multiple input, multiple output. Basically this just means using more than one antenna at a time to double, triple or quadruple the speed – Gen 4 could use up to 4 sender and 4 receiver antennas, often written as 4×4. All of that combines to a throughput of between 250 and 600 Mbps, depending on the frequency, channel, QAM and how many antennas were in use.

WiFi 5, that’s ac, that was a bit of an interesting one, as that was 5GHz exclusive, and often why there were two SSIDs for one network, because 2.4GHz operation was still run with Gen 4, while 5GHz operation was Gen 5. Confusing, right? Well WiFi 5 made some big improvements to the 5GHz network anyway. It increased the QAM – the amount of data sent at a time – to 256, up from just 64 on WiFi 4, it added much wider bands – now 20, 40, 80 and 160 MHz channels were available, up from the max of 40 with WiFi 4, and now you could even use 8 sending and receiving antennas if you wanted for a theoretical maximum of 6.9Gbps – although most real world devices ran at around 1.7Gbps at most. Technically those 160MHz bands and the wider MIMO support came three years later with “Wave 2” devices (2016 onwards). Standards organisations suck at naming stuff, because for most people you’d struggle to know if your device was Wave 1 or Wave 2. One pretty big feature that was added in Wave 2 was DL MU-MIMO – that’s downlink multi-user MIMO – which is important as that whole using multiple antennas for faster transfers was actually only available to one device at a time, but with MU-MIMO that became available to multiple devices at a time, at least for downloads from the router anyway. One other feature you should know about here is something called Beamforming. This is essentially where the router – well the wireless access point specifically – picks which antennas the receiving device is connected to with the strongest signal and prioritises sending data to that device with those antennas. It’s simple, but can make a difference in the speed and signal quality for sure.

WiFi 6 and 6E are both 802.11ax, although 6E is the real star here. WiFi 6 upped the QAM to 1024, and added a new feature called OFDMA – which is Orthogonal Frequency Division Multiple Access, catchy, I know. Basically that means it can sub-divided the channels for multiple users to help up the throughput especially with a busy network. I have to imagine this is more useful in public spaces than at home, but even for a few people at home, one who’s gaming and streaming, and a few who are streaming videos, being able to split a channel up so they all get data at the same time means the gamer gets lower latency while the people watching videos get an uninterrupted experience. WiFi 6 also added a new security protocol, WPA3, which suffice to say is better than WPA2 from previous versions, but still not exactly perfect. WiFi 6E though adds a whole new frequency, 6GHz. So there is now 2.4GHz, 5GHz and 6GHz signals, for a theoretical maximum of 9.6Gbps – although realistically it’s more like 2.4Gbps max. Oh, and WiFi 6 also added uplink support for the MU-MIMO feature, so now traffic going both ways can use multiple antennas for faster transfers.

Lastly for the current WiFi standards, WiFi 7. That’s 802.11be, and added a new 320MHz band, 4x larger QAM at 4096, and the important one is multi-link operation. That means devices can connect with two bands or frequencies at the same time, either for speed or redundancy, which in theory means straight double the performance. That means up to 5.8Gbps real world speeds, which is incredible. An advancement to the OFDMA feature is Multi Resource Units and Puncturing, which basically upgrades the ability to actually split up these new wider channels when they aren’t being fully utilised, again generally more helpful for busy access points, but it might still be useful at home. 

One feature you might have heard of, and are a little confused why it hasn’t been mentioned yet, is “mesh”. Mesh routers and access points have become pretty popular, and yet they aren’t part of the WiFi standard. Mesh is a feature where a WiFi router or access point can connect to other access points – often called satellites – to extend WiFi range. This is different to WiFi range extenders in one key way – they don’t use WiFi to extend the range. My Netgear Orbi router for example uses a proprietary wireless connection to connect between the router and satellites, which means the WiFi frequencies are left clear for your WiFi traffic. Mesh is, at least currently, a proprietary technology each brand implements in their own way. It’s similar to enterprise WiFi access points that are generally wired, but offer fast roaming between access points, so even in a large area like a train station or airport you can connect to one SSID but to various access points as you move around the building. 

So, that’s WiFi explained. There is of course plenty more detail we could go into here, but I think this is a decent overview to explain what each version means, and what each version offers so you can know which version is for you. I’ve learned a lot just making this video, so I hope it has been useful for you too. If I’ve missed anything, or you have any questions, feel free to leave them in the comments below!