Making sense of all the different types of Wi-Fi

Everyone’s worst fear: To be stuck in your bathroom, doing your business, when suddenly your Wi-Fi connection drops. What are you supposed to do without Internet? Read the ingredients of your shampoo bottle, like your ancestors did?

Jokes aside, setting-up a Wi-Fi connection that’s fast, strong, reaches all the rooms in the house is no easy feat, and all the different versions, standards and frequencies don’t help. I’ll try to give a crash-course on this topic.

Different versions of “Wi-Fi”

This may shock you, but Wi-Fi wasn’t always as fast as it is now. These are the different versions of Wi-Fi that were created over the years, and are still in use now (I don’t want to fill your head with esoteric bull***t that no one uses anymore):

  • 802.11b: Introduced in the year 2000. Its maximum theoretical bandwidth is 11 Mbps. That’s lowercase b, which means bits, not bytes. It translates to maximum theoretical downloads of about 1.4 MB/s.
  • 802.11g: Introduced in the year 2003. Its maximum theoretical bandwidth is 54 Mbps (6.7 MB/s).
  • 802.11n: Introduced in the year 2009. It allows the router and the device to have multiple antennas, so the total bandwidth achievable depends on how many simultaneous connections can be made. For example, if the router has 4 antennas but the laptop has 2, only 2 connections can be established. It can reach up to 150 Mbps per connection.
  • 802.11ac: The fastest version currently available. Depending on the channel width and number of antennas, it can reach up to 1.3Gbps (162 MB/s).

Just so you have a baseline, any decent router can give 1Gbps of bandwidth using an Ethernet cable, and that’s been true for years. A wired connection is also more power-efficient, has less latency, and of course is much more resistant to interference and attenuation.

Those bandwidth numbers may seem good on paper, but that’s on a laboratory, shielded from any external interference, and with the router close to the device. In real-world scenarios, you’ll probably never get half the maximum speed of your connection.

Bands and channel widths

Oh, you thought that was all? Nope!

Wi-Fi traditionally uses the 2.4GHz band. That’s the same band Bluetooth uses (this piece of information will become relevant later). That band is also divided in 20MHz channels. So, if you have configured your router to use “Channel 1”, you’ll be transmitting at 2400-2420MHz. If you choose “Channel 11” (usually, the highest, although that depends on your country’s regulations), you’ll be transmitting at 2450-2470MHz.

Wi-Fi version 802.11n allows the channels to be wider, 40MHz to be precise. That allows double the bandwidth per-channel. Wi-Fi version 802.11ac just goes crazy with that idea and allows channels of up to 160MHz.

Starting with 802.11n, Wi-Fi can transmit in the 5GHz band too. The 5GHz band can use wider channels, and because it’s a relatively new addition, it’s less saturated than the 2.4GHz band. But, because of physics, that transmission doesn’t travel well through obstacles.

Enough theory, how do I configure my router?

Enough theory indeed. Let’s assume that you already have a router. The first thing you need to know is its capabilities. If you got it in the latest 2 years or so, it probably has 802.11ac. If not, unless it’s incredibly old, it will have at least 802.11n.

If the router is modern, it probably has 5GHz capability. Those routers usually provide 2 different Wi-Fis at the same time: One in the 2.4GHz band, and another on the 5GHz band (usually named “Wi-Fi Plus” or some marketing gimmick like that). So, you can connect your laptop to the 5GHz and your old phone to the 2.4GHz. Apple hardware usually has 5GHz capabilities too, even if it’s older. My old 2011 MacBook Air and the Time Capsule I bought at around the same time both have 802.11n and support for 5GHz.

The next thing to know is the capabilities of your devices. Some rough estimates:

  • 802.11g: Super-old budget smartphone.
  • 802.11n: Kindle, 4-year-old high-end computer, 2-year-old budget computer, any Internet of Things device, 2-years-old budget smartphone.
  • 802.11ac: 3-year-old high-end smartphone, 3-year-old high-end computer.

Of course, a modern device can connect to older kinds of networks. The best way to confirm if your device supports a version of Wi-Fi is to configure your router to use only that version and then try to connect. But it’s not really that important to know.

If you use Bluetooth, use the 5GHz Wi-Fi. Laptops usually use the same antenna to transmit Wi-Fi and Bluetooth, so if they are trying to transmit at the same frequency (remember, Bluetooth uses the 2.4GHz band) there will be a lot of interference. With my Dell XPS laptop (a high-end computer), if I’m connected to a 2.4GHz network I practically can’t use my Bluetooth mouse.

If you live in a big house, use the 2.4GHz band. A 2.4GHz signal can easily travel through 2 or 3 walls before attenuating a lot. Laptops have bigger antennas, so they can get stronger signal, but smartphones are more problematic. If you connect a smartphone to a 5GHz Wi-Fi and go to the next room, chances are your speed will drop drastically.

If you have a lot of neighbours, use the 5GHz band. That’s the plus side of the 5GHz band not being able to travel through obstacles: your neighbour’s Wi-Fi can’t generate as much interference on your home. Plus, 5GHz being a relatively new addition, chances are that most of your neighbours won’t be transmitting in that band at all.

Speaking of neighbours: channel selection. If your neighbour is using Channel 1, switch to Channel 6 or higher so there’s no overlap. If they’re using Channel 6, use Channel 1 or 11. Leave 5 channels in between you. Of course, with multiple neighbours that trick is not so easy. The best thing to do is just let your router configure the channel automatically, it will pick the less congested band.

Channel width: Routers will usually let you pick whether you want 40MHz channels, 20MHz channels, or support both kinds at the same time. Just leave it to “support both”, there’s no reason not to.

Wi-Fi version: Routers will also give you the option to configure which versions to support. For example, if the router is 802.11n, it will give you these options:

  • 802.11n only.
  • 802.11g and 802.11n.
  • 802.11b, 802.11g and 802.11n.

Just leave it with support to all of them. Again, there’s no downside to that.

Tell us Daniel, how do you have your router configured?

I’m glad you asked, voice in my head. Let it serve as a small example. I live in a small apartment, the router is in the living room, and there aren’t a lot of neighbours. My router supports 802.11ac, and it provides 2 Wi-Fi signals: One at 2.4GHz and another with 5GHz. I have left the Channel and channel width to “Automatic”, and Wi-Fi support to 802.11b/g/n/ac (I don’t want having a guest with an old phone and it mysteriously not working).

These are my devices:

  • OnePlus 3 (smartphone): Supports 5GHz and 802.11ac. I have it connected to the 2.4GHz network, because if I use the 5GHz the signal drops when going to the next room. I don’t really need ultra-fast speed on my phone anyway.
  • Kindle (e-reader): Supports 802.11n (I think). I have it connected to the 2.4GHz network. I almost don’t use the Wi-Fi on this one, I don’t really care if a book takes 2 more seconds to download.
  • Dell XPS 15 (laptop): Supports 5GHz and 802.11ac. I have it connected to the 5GHz network. As I said, if I connect it to the 2.4GHz, the Bluetooth mouse becomes jittery. I work in the same room where the router is, so range isn’t an issue.

This kind of arrangement won’t work for everyone, but I think it’s a good baseline. Basically, pick 5GHz unless you need extreme range, and keep the default router options (all versions of Wi-Fi supported, automatic channel selection, etc). Also, if you have a lot of neighbours and your router doesn’t support 5GHz, do yourself a favour and invest in one that does. The difference is abysmal.

I hope I’ve shed some light into the matter, and not confuse you even more, my hypothetical reader. Please tell me in the comments if you have any doubt or question with your setup.

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