How to Find the Best WiFi Channel

What Makes Channels 1, 6, and 11 Special?

While the 5 GHz band has 24 non-overlapping channels, the 2.4 GHz band has only three non-overlapping channels: 1, 6, and 11.

To make matters worse, not all WiFi routers and their users know that they should be using only non-overlapping WiFi channels because the use of any other WiFi channel is guaranteed to result in adjacent-channel interference.

Why does the use of other WiFi channels results in adjacent-channel interference? Because channels in the 2.4 GHz band have a WiFi channel width of 20 MHz, which would be fine if they were not spaced only 5 MHz apart. As a result, channel 3, for example, overlaps with both channels 1 and 6, and the same is true for channels 2, 4, and 5. Likewise, channels 7, 8, 9, and 10 overlap with channels 6 and 11.

Users sometimes believe that the best WiFi channel is the one that’s used the least, which is why they end up picking an overlapping channel and cause more harm than good. To really find the best channel for WiFi, you need a WiFi channel analyzer or scanner and a little bit of know-how.

What About Non-Overlapping Channels in 5 GHz and 6 GHz?

The 5 GHz band offers a significant advantage with 24 non-overlapping channels, thanks to wider spacing and a larger spectrum allocation. This minimizes interference and provides more flexibility, especially in environments with dense WiFi usage.

The 6 GHz band takes this further, introducing up to 59 new non-overlapping channels in some regions. These channels are even wider (up to 160 MHz) and virtually interference-free, as the band is currently less crowded. This makes 6 GHz ideal for high-speed, low-latency applications.

Choosing non-overlapping channels in any band is critical for optimal performance, but the newer 5 GHz and 6 GHz bands give users far more options than the congested 2.4 GHz band.

Common Wi-Fi Channel Overlap Scenarios and Solution

Partial Overlap

Partial overlap occurs when nearby networks use channels that are close but not identical, such as channels 4 and 6. In these cases, overlapping signals create interference that devices perceive as noise, leading to slower speeds and reduced reliability.

Solution: Use a WiFi analyzer like NetSpot to identify channels with partial overlap and switch to a fully non-overlapping channel. If your router supports it, consider switching to the 5 GHz or 6 GHz band, where there are more available channels and less congestion. If no other options are available, switching to a channel with full overlap (see below) might still be a better choice.

Full Overlap

Full overlap occurs when multiple networks broadcast on the same channel, such as two routers operating on channel 6. Surprisingly, this scenario is more manageable because networks can coordinate transmissions using protocols like CSMA/CA, which minimize interference and improve overall stability.

Solution: If no non-overlapping channels are available, choose a channel already heavily in use by nearby networks. This counterintuitive approach often leads to better performance than partial overlap, as devices can work together to manage traffic.

Non-Overlapping Channels

Sometimes, you may find completely free or minimally occupied channels. This situation offers the opportunity to switch your network to one of these channels, ensuring excellent performance with minimal interference.

Solution: If free or low-usage channels are available, immediately reconfigure your network to use one of them. This not only eliminates interference from other networks but also maximizes signal strength and stability. It’s still essential to periodically monitor your environment, as other networks might begin using the same channel over time, requiring adjustments to maintain optimal performance.

By taking advantage of free channels and using tools like NetSpot for regular monitoring, you can stay ahead of potential interference and maintain a fast, reliable WiFi connection.

When using NetSpot to find the best WiFi channel, you need to keep in mind that your ultimate goal is to avoid co-channel interference, which occurs when two or more WiFi routers operate on the same channel or neighboring channels.

Here are some basic WiFi channel planning best practices to help you achieve this goal:

• Analyze WiFi channels at different times of the day: Some WiFi networks, such as those created by printers and wireless security cameras are active only during certain times of the day, so it pays off to analyze WiFi channels more than once.
• Consider the strength of each found network: The number of networks using a WiFi channel isn’t the only factor that matters. It’s sometimes better to use a channel that’s utilized by three other networks that are very far away than one network that’s very close.
• Upgrade to a dual-band or tri-band router: If you’re still using a single-band router, consider upgrading to a dual-band or tri-band model. These routers can broadcast on both the 2.4 GHz and 5 GHz bands (and even the 6 GHz band if they support WiFi 6E), reducing interference and congestion. Modern routers are relatively affordable, with excellent models available for under $100.
• Monitor changes in network activity: WiFi environments are dynamic, and new networks may appear over time. Regularly analyze your WiFi channels with NetSpot to maintain optimal performance.

By following these these best practices, you can optimize your WiFi network to achieve faster download and upload speeds, reduce interference, and minimize latency issues.