20MHz vs 40MHz vs 80MHz vs 160MHz: What Channel Bandwidth Should I Use?

20MHz vs 40MHz vs 80MHz - What channel bandwidth should I use

What Channel Bandwidth Should I Use?

The channel bandwidth you use for your Wi-Fi network can really affect the performance on your network.

There are a number of things you should consider when choosing which channel bandwidth is best for you, including how crowded the channels are and the kind of throughput you will need in your network.

What Channel Bandwidths on 2.4GHz and 5GHz?

On The 2.4GHz Frequency Band

When using the 2.4GHz broadcasting radio you should generally use a channel bandwidth block 20MHz wide. This is because there are more non-overlapping channels available when using 20MHz (as opposed to 40MHz) which means there is less liklihood of congestion or clashing channels.

You can also use 40MHz on the 2.4GHz broadcasting radio. However it congests the Wi-FI in the area so if you live in a built up area it probably isn’t a great idea as it will interfere with other 2.4GHz users.

On The 5GHz Frequency Band

When using 5GHz, however, it is possible to use wider channel bandwidths for increased bandwidth. As such on the 5GHz channel you can use the 40MHz, 80MHz or even the 160MHz channel bandwidths (if your router or AP supports it) for increased bandwidth.

2.4GHz vs 5GHz Wi-Fi, what’s the difference?

Should I Use 20MHz, 40MHz 80MHz?

Basically, higher channel bandwidths can support a higher data rate and more bandwidth. The downside is that as you increase the channels you will find that there are fewer channels available which can lead to problems (yup, that old problem with congestion again!).

20MHz is the most common Wi-Fi bandwidth as most users still opt to use 2.4GHz radios. The 2.4GHz band is fairly crowded which can cause problems connecting in certain environments.

In an environment with less congestion where a higher data throughput is required, using the 40MHz channel can be a good idea as it still offers 12 non-overlapping channels on 5GHz.

80MHz is available on many 802.11ac routers and offers an even wider channel and as such even higher bandwidth. However, this makes it even more susceptible to co-channel interference (yet again, congestion...wow this is getting repetitive!). 80MHz channels are therefore best off used on a best-effort basis but only when the entire channel range is clear.

One possibility is to connect low-bandwidth devices that don’t require high speeds such as printers to your 2.4GHz channel and your laptops and phones onto a 5GHz channel. This will free up bandwidth on the wider channels for your bandwidth-hungry products such as laptops and smartphones that take up more data.

What About 160MHz?

160MHz is a wide channel available in the 5GHz band. 802.11ac Wi-Fi offers two options for creating 160MHz channel. These are 160MHz operation which involves one 160MHz channel. This involves creating a 160MHz channel by combining transmissions on two 80MHz channels.

Using 160MHz of bandwidth offers higher speeds, but as there is only one huge channel being used, this congests the local area. 80MHz+80MHz operation allows you to take advantage of 160MHz worth of bandwidth.

Of course, due to the lack of channels available, it is not advisable to use 160MHz in a built up area as it will likely attribute to wireless congestion. You won't be popular with the neighbors, that's for sure!

If you have any questions about which Channel Bandwidth you should use on your network, please comment below.

5 Comments - Write a Comment

  1. You keep using the term “in a built up area” but that is a vague description & different people will have differing ideas of what a built up area looks like

    Reply
    1. · Edit

      Hi sdmf74,

      Sorry, your comment somehow deleted, so I added it back in manually…

      Thanks for your comment.

      Basically, the more built-up an area you are in, the more likely it is that congestion will occur. Suburbia (separate homes with gardens) is considered built-up, yes, but the chances of congestion are much less compared to say…Downtown Manhattan, where population density is far higher, for example.

      Reply
  2. Great article, very informative and just what I was looking for. I just had Comcast install their latest 1 Gb service with the new modem but my wireless network coverage area has shrunk by at least 20 feet and my lower bandwidth devices went from around 130mb connection to 54 and drop out at locations they had been work from for over a year. I live in Suburbia, I see 4 wireless networks in my area. I have the option of setting the channel width up to 160. Would setting my 2.4 to 40 help my lower bandwidth devices that are further away from the modem get a better connection rate?
    Thanks!

    Reply
    1. · Edit

      Hi Caged,

      Thanks for your question.

      The best thing to do is try for yourself. Run several speed tests from close by to the router/access point and get a solid average. Then try the same again from the ‘further away’ area on 20MHz, then again on 40MHz, and see how that goes.

      If you’re feeling more adventurous (and technical), you can get a lot more info (on signal strength particularly) if you install a wifi analyzer (like Acrylic: https://www.acrylicwifi.com/en/wlan-software/wlan-scanner-acrylic-wifi-free/).

      Just be aware that using 40MHz on the 2.4GHz band will have an impact on your neighbors. It all depends how close they are to you.

      Also, if you are able to log into your new device, I would recommend checking to see what wireless mode the router is using. If it’s on “mixed b/g/n/”, then change it to support your slowest device. Any Wireless G device (even if it’s not on your network – so a neighbors, for example) will likely slow down your wifi network considerably.

      Hope this helps!

      Reply
  3. FYI the new modem is Arris TG3482G

    Reply

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