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). The table below lists all 11 Wi-Fi channels that are available in North America and specifies the exact frequency range of each:
|Channel number||Bottom of channel||Center frequency||Top of channel|
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.
As the table above illustrates, channels 2, 3, 4, and 5 overlap with both the channel 1 and 6, while the channels 7, 8, 9, and 10 overlap with both the channel 6 and 11. This means that when channels 1, 6, and 11 are crowded, all channels between them are affected as well.
If you live in an area with many Wi-Fi networks on channels 1 and 6, switching to the channel 3 or 6 won’t likely help improve your signal at all. In fact, it can result in the loss of signal strength as a result of the increased amount of interference.
As a rule of thumb, always stick with channels 1, 6, and 11 even if they are crowded. Of course, you can always experiment with other channels, but make sure to verify your signal strength and the performance of your network with NetSpot.
All Wi-Fi connections can be negatively affected by electromagnetic interference, also called radio-frequency interference, which happens for three main reasons:
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. This type of Wi-Fi interference isn’t actually electromagnetic interference. Instead, it’s a result of Wi-Fi routers doing their best to give one another room to transmit data.
Think back to when you were in elementary school and your teacher asked the whole class a question. The chances are that multiple kids started shouting at once and nobody could hear anything properly. That’s basically what co-channel interference is, which is why Wi-Fi routers take turns and politely wait for one another to finish.
Adjacent-channel interference happens when clients on overlapping channels talk at the same time. Wi-Fi channel selection is crucial in cases like this. Such channel-related interferences can be cut down or excluded by choosing the proper Wi-Fi channel for your network.
NetSpot can help you reveal which Wi-Fi channels are cluttered the most so you can avoid them and use other channels instead, preferably channels 1, 6, or 11 because these three channels are non-overlapping. Fortunately, modern Wi-Fi routers are able to cope with adjacent-channel interference much better than older routers, many of which default to the same Wi-Fi channel.
In addition to Wi-Fi routers, there are many other electronic devices that can interfere with the 2.4 GHz band. Some interfere with it because they use it to wirelessly transmit data, such as security cameras, Bluetooth devices, baby monitors, and smartphones, while others interfere with it because they emit a large amount of electromagnetic radiation, such as microwaves and other appliances.
To avoid non-Wi-Fi interference, it’s important to place your Wi-Fi router far away from all sources of electromagnetic radiation, preferably also away from solid objects, including walls, large pieces of furniture, and so on.
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.
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.
5 GHz channel band compatibility:
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.
If you own a fairly modern Wi-Fi router, there’s a good chance that it supports both the 2.4 GHz or 5GHz channel band. Because support for the 2.4 GHz band precedes the 5 GHz band, you might come to the conclusion that the 5 GHz band is always better. In reality, both bands have their pros and cons that you should be aware of to know which one to use.
In general, higher frequencies have a harder time penetrating solid objects, such as walls and trees, which is why the 5 GHz band is not great for broadcasting data across long ranges.
The good news is that modern Wi-Fi routers can readily use both the 2.4 GHz and 5 GHz channel band at the same time, giving you the best of both worlds. Such routers are called “dual-band,” and they are well worth their higher price.
There are even “tri-band” routers, which broadcast one signal in the 2.4 GHz band and two signals in the 5 GHz band. Tri-band routers tend to be very expensive, but they are indispensable in highly congested areas, such as city centers.
If you can’t use both the 2.4 GHz and 5 GHz channel band at the same time, we recommend you test bands independently and choose the one which allows you to achieve higher data transfer speeds and lower latency.
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.
Finding the most suitable WiFi channel can improve your wireless experience tremendously. But it's not just the speed you should be looking at, the overlapping is an important factor as well. The most popular WiFi channels for 2.4 GHz frequency are 1, 6, and 11, because they don’t overlap with each other. Use these channels with a non-MIMO setup (i.e. 802.11 a, b, or g).
The three main reasons for wireless interference are:
Starting with the 802.11n standard, wireless technology became very advanced. If you purchased your router within the last couple of years, chances are you have either a 802.11n or 802.11ac one.
The 5 GHz band offered with these specifications provides lots of free space at the higher frequencies — 23 non-overlapping 20MHz channels — and the router will choose the best wireless channel for your connection automatically. Using the 5GHz band in a space with thick walls usually means very little WiFi interference.
There are two frequency bands that you can choose from: 2.4 GHz and 5GHz. Newer routers support both of these bands and it's up to you to decide which one works better for your connection. The 2.4 GHz band goes longer distances, but transmits data slower. The 5 GHz band coverage doesn't travel far, but is very fast and can penetrate obstacles better than 2.4 GHz.
NetSpot can visualize your network coverage to help you see the possible reasons for any wireless issues. NetSpot can also help you choose the best channel for your network. Simply open the NetSpot app and click Discover; then 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 using it.