WiFi Channel Width: What is it, Which, and When To Use?

Channel width is all about the frequency range of a specific WiFi channel. It can greatly affect the performance of a wireless network, so it’s important to select the right width. But it ain’t always easy to get it right.

If the wireless channel is not set up properly, you may not experience good download and upload speeds. Maintaining best practices can be challenging due to the numerous existing standards and tradeoffs.

The most commonly used channel widths in wireless networks are 20, 40, 80, and 160 MHz. Simply put, the wider the channel width, the greater the amount of data that can be transferred. Let’s take a closer look at these channel widths to under which one best suits your internet usage.

What is WiFi Channel Width?

The wireless channel width determines how wide the signal is for data transmission. Consider it similar to a highway.

If the road is wide, more traffic (data) can travel through it. However, the more trucks (routers) on the track, the more jammed the traffic becomes.

The bandwidth of a wireless broadcast can be sped up by increasing the channel width.

• The channel width for the 2.4 GHz frequency is 20 MHz by default.
• A channel width of 20 MHz is sufficient to span a single channel.
• A 40 MHz channel width brings together two 20 MHz channels to establish a 40 MHz channel width, allowing you to boost the WiFi router’s speeds.

So, arguably, two channels are preferable to one, right? Yes, theoretically.

However, this is not the case if channels are clogged with interference and noise. A single 20 MHz channel would be more stable in congested areas with significant frequency interference and noise.

Although a 40 MHz channel width enables faster transfer and higher speeds, it doesn’t perform very well in congested areas.

But then, it is best to use wider channels in most home environments. You may even use wider 40, 80, or 160 MHZ channels in your house or small office. If you have got a new router and WiFi access point, you can head to the router settings and try increasing the channel width and see if there is any difference in speeds.

Channel Bandwidth 20, 40, 80, and 160: Explained

Now that you know what wireless channels are, let’s move on to how to pick the right one for your router. Note that device support is required before using any specific channel width.

Should you choose a particular channel bandwidth, such as 160 MHz, or leave the default setting of 20, 40, or 80 MHz on most routers and access points? Well, it depends on how much potential interference there is around your network.

Most users prefer 2.4 GHz over 5 GHz because of improved wireless range; hence, 20 MHz is the most commonly used 2.4 GHz channel width.

Similarly, using the 40 MHz channel width can be smart in less congested conditions where higher bandwidth is required because it still provides 12 non-overlapping channels on the 5 GHz band.

80 MHz channels should only be used on an ideal premise when the entire connection range is clear. Although the 5 GHz band has a wide channel at 160 MHz, only one non-overlapping channel is available, so interference compromises must be considered.

When To Use 20/40/80 MHz in 2.4 GHz?

The answer is simple: when you’re using 2.4 GHz. 20 MHz is the best channel width for 2.4 GHz. Most of the time, using wide widths on 2.4 GHz is not advantageous.

The bandwidth advantages will probably be outweighed by the performance loss associated with interference on overlapping channels. Remote areas with fewer WiFi connections or devices can be an exception to this rule.

If you require a faster data transfer rate, use the 40 MHz or 80 MHz channel width. However, even little traffic on such a network is likely to cause congestion. This is because you don’t have enough non-overlapping channels to work with. As a result, you are more likely to encounter channel interference.

When To Use 20/40/80/160 MHz in 5 GHz?

Wider WiFi channel widths, such as 40 MHz and 80 MHz are among the best channels for 5 GHz WiFi frequency. Not only are there a lot more WiFi channels in this band, but there are also fewer overlapping channels.

However, the most non-overlapping channels are available when using 20 MHz, whether you’re using 2.4 GHz or 5 GHz. In areas with high densities and where network interference is a significant issue, 20 MHz makes sense.

To balance out interference reduction, bandwidth, throughput, and latency, use 40 MHz. By doing this, you can enhance performance in comparison to 20 MHz without running the risk of encountering 80 MHz interference.

Consider using 80 MHz if your devices are close to your WiFi router, your devices support it, interference isn’t a major problem, and you want to maximize bandwidth.

I tested several access points and WiFi routers that support 160MHz and found that the network throughput was very close to when the channel width was set at 80MHz; however, it was significantly unstable.

Using the 160MHz channel bandwidth is a good idea in a few cases. This includes when there is minimal to no network interference when your WiFi devices are super close to the router, and when you truly need that bandwidth.

How About Automating WiFi Channel & Width Selection?

High interference can lead to slower upload and download speeds, which is typically expressed as low throughput. As a result, when choosing its operating channel, an Access Point (AP) must be able to identify and avoid interference.

Automatic Channel Selection (ACS) is an advanced feature that automatically assigns wireless access points to the best channel for each network depending on a number of indicators that account for issues such as interference from other WiFi networks.

In short, ACS starts at boot up to search the best channel width for 2.4 GHz & 5 GHz and throughout operation to maintain peak performance.

Here’s the step-by-step explanation for the same:

1. Auto-channel operates by scanning for all wireless channels nearby by the access point.
2. Following the completion of the channel scan, the access point discards channels with airtime utilization greater than 40% by non-WiFi sources.
3. When finished, it chooses the “clean” channel and is not utilized by any other wireless network.
4. This is done periodically to ensure the network runs on the best channel possible.

Note: It’s not just about choosing the right wireless channel. For better performance, you should also get your router placement right.

However, if that doesn’t help, you might have faulty equipment by your side. Know how to choose a WiFi router and upgrade one for your home network.

Frequently Asked Questions

Conclusion

So, that was all you need to know about the channel width in WiFi. I hope you are now clear about the WiFi channel selection for your connection. If you still have any queries or suggestions, feel free to share them in the comments below. I’ll surely respond to each of you! That said, I’m signing off.