20MHz vs 40MHz vs 80MHz vs 160MHz: 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.

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20MHz Channel Bandwidth

The 20MHz channel bandwidth is the most basic option available for Wi-Fi networks, often considered the default setting on many routers.

This bandwidth is widely supported across all Wi-Fi standards, including 802.11b, 802.11g, 802.11n, 802.11ac, and 802.11ax.

It is commonly used in the 2.4GHz frequency band but is also supported in the 5GHz band.

Why Use 20MHz?

1. Compatibility: The 20MHz bandwidth is universally compatible with a wide range of devices, including older ones that may not support wider channels.
2. Minimal Interference: Due to its narrower width, the 20MHz channel is less likely to overlap with other channels, thereby reducing the chances of interference.
3. Stable Performance: This bandwidth is particularly useful in environments with many competing wireless networks, like apartment buildings or office complexes.

Drawbacks

• Speed Limitations: Its narrower channel width limits the maximum throughput, which can be a bottleneck for high-speed applications.

40MHz Channel Bandwidth

The 40MHz channel bandwidth doubles the width of the 20MHz channel, offering higher potential data rates.

This bandwidth is most beneficial in the 5GHz frequency band due to the wider range of non-overlapping channels available.

Why Use 40MHz?

1. Higher Data Rates: By combining two 20MHz channels, the 40MHz bandwidth significantly increases the potential data rate, which is beneficial for streaming and gaming.
2. Moderate Interference Handling: While it still experiences some interference, the 40MHz channel is less prone to the severe congestion common in urban areas compared to 80MHz or 160MHz channels.

Drawbacks

• Compatibility: Some older devices may not support 40MHz channels.
• Potential for Interference: In crowded environments with many networks, the 40MHz channels may overlap more, leading to potential interference.

80MHz Channel Bandwidth

With an 80MHz channel bandwidth, the throughput potential increases even further, making it particularly useful for high-speed applications.

This bandwidth is prevalent in routers supporting 802.11ac and newer standards.

Why Use 80MHz?

1. Very High Data Rates: Ideal for applications requiring significant bandwidth, such as 4K video streaming and large file transfers.
2. Modern Compatibility: Newer devices, which frequently support 802.11ac and 802.11ax standards, can take full advantage of 80MHz channels.

Drawbacks

• High Interference Risk: In densely populated areas, 80MHz channels are likely to overlap with others, causing significant interference.
• Limited Availability: In the 5GHz band, the number of non-overlapping 80MHz channels is limited, making it a less viable option in crowded areas.

160MHz Channel Bandwidth

The 160MHz channel bandwidth offers the highest potential throughput in the Wi-Fi spectrum, aligning with the capabilities of modern 802.11ax (Wi-Fi 6) routers.

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!

Why Use 160MHz?

• Maximum Throughput: Deliver the highest possible data rates, suitable for intensive applications like virtual reality, large data transfers, and more robust streaming services.
• Future-Proofing: Using 160MHz channels prepares your network for future technologies and devices that will demand more bandwidth.

Drawbacks

• Extreme Interference: The risk of interference is highest with 160MHz channels, which may severely impact performance in congested environments.
• Restricted Usability: The availability of 160MHz channels is very limited, and regulatory constraints may further restrict their usage in some regions.

What Channel Bandwidths Are Available 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?

So, Should I Use 20MHz, 40MHz, 80MHz or 160MHz?

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.

And 160MHz? Use this if you are a bad a$$ 🙂

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