In your router's settings there are channel settings. Most routers have channel settings set to "Auto", but if you look through the list, there are at least a dozen of WLAN channels. So how do you know which WiFi channels are faster than the others in that list? Choosing the proper WiFi channel can vastly improve your WiFi coverage and performance. But even if you find the fastest channel there it doesn't always mean you should select it right away.
Various frequency bands (2.4GHz, 3.6 GHz, 4.9 GHz, 5 GHz, and 5.9 GHz) have their own range of channels. Usually routers will use the 2.4GHz band with a total of 14 channels, however in reality it may be 13 or even less that are used around the world.
All Wi-Fi versions through 802.11n (a, b, g, n) work between the channel frequencies of 2400 and 2500 MHz. These 100 MHz in between are split in 14 channels 20 MHz each. As a result, each 2.4GHz channel overlaps with two to four other channels (see diagram above). Overlapping makes wireless network throughput quite poor.
Most popular channels for 2.4 GHz Wi-Fi are 1, 6, and 11, because they don’t overlap with one another. You should always try using channels 1, 6, or 11 when on a non-MIMO setup (i.e. 802.11 a, b, or g).
Co-channel interference. In networks where devices take turns to talk, it takes time for each of them to wait for their turn. Therefore the more devices the longer the wait time.
Adjacent-Channel interference. WiFi channel selection is crucial in cases like this. Such channel-related interferences can be cut down or excluded by choosing the proper WiFi channel for your network.
A WiFi channel scanner like NetSpot helps you see through the network and choose the proper channel or reduce WiFi interference. Using NetSpot channel scanner will help you improve your 2.4 GHz WiFi network performance.
As said above every wireless channel on the 2.4 GHz spectrum is 20 MHz wide. When using 802.11n with 20 MHz channels, choose the 1, 6, and 11 ones. If going to use 40MHz channels, take into consideration that the airwaves may be congested, unless you live in a house in the middle of a very large property.
The whole spectrum is 100 MHz wide and the channel centers are separated by 5 MHz only. This leaves no choice to eleven channels but to overlap.
And again for the best throughput and minimal interference, channels 1, 6, and 11 are your choice. Depending on the neighboring WiFi networks one channel can be a better choice than another.
E.g. if you choose channel 1, but your neighbor is using channel 2, then you'll want to switch to 11 to completely avoid overlapping, though 6 can work as well if not better. As tempting as it is to use the channels other than 1, 6, and 11, remember that everyone around will be stomping on your throughput and you can become the reason for channel interference.
It would be a perfect setting to talk with all the neighbors and set up each router to channels 1, 6, 11. If you have a thick brick wall between you and your neighbor using the same channel 1 probably wouldn't hurt, but if there is a thin wall between you, try working on using different wireless channels.
The 5 GHz (802.11n and 802.11ac) band actually offers way more free space at the higher frequencies. It offers 23 non-overlapping 20MHz channels.
Starting with 802.11n and going to 802.11ac, wireless technology became much more advanced. If you bought a WiFi router within the last couple of years, then you probably have a decent 802.11n or 802.11ac router. Most of them have a hardware inside that automatically selects the proper WiFi channel and adjusts the output power thus boosting throughput and cutting down the interference.
Using the 5GHz band and having decently thick walls as well as the general lacking of 5GHz devices usually means that there is a very little interference in your space. In cases like this you may benefit from using the 40, 80, and 160MHz channels.
Ideally, as everyone gradually upgrades their hardware and starts using 5GHz band, having to select the proper WiFi channel will become obsolete. It is especially applicable to MIMO setups (up to eight in 802.11ac), when it is a better idea to let your router do its own thing. Of course there will be custom cases like fine-tuning the channel selection for your router. Eventually, even the 5GHz will fill up, but by the time it happens we should be able to figure higher WiFi channel frequencies out. Or maybe entirely new antenna designs will be created for the high-end demands of wireless networking world.
NetSpot is very good at visualizing the networks to help you make the right decision.
With NetSpot's visualization you will immediately see the cause of the wireless issues and how to eliminate them. You can get the recommendation on which channel to use and the best thing about it — you don't have to be a WiFi professional to choose the optimal channel for your network. All you need to do is just open NetSpot app and click Discover. Click the "Channels 2.4 GHz" header to see where Wi-Fi channels are overlapping. Look for the channel (out of 1, 6 and 11) with the least number of networks present on it.
The “Show average value for inactive networks” option is enabled by default in NetSpot, which means you'll see even currently inactive networks and their average values. You can disable this option when you don't need the data for currently inactive networks. The active networks are shown in solid lines on the graph.
In the above graph the selected network is operating on channel 5, and overlaps with channels 2 and 8. You can see that channels 6 to 9 have the smallest number of networks and overlapping is not that bad at all. So in this particular case if you need the best WiFi channel, choose from channels 6 to 9.
