WiFi supports two different bands, which are 2.4GHz and 5GHz. Each band is divided into channels. The bands and channels used for a network can greatly impact performance and reliability.
Channel width dictates the amount of bandwidth used within the radio spectrum during transmission. Using more bandwidth can lead to faster speeds, but also increases the chances that you’ll be interfered with by someone else also using the same area of the radio spectrum. WiFi bandwidth is measured in megahertz(MHz). The minimum channel width needed is 20MHz. 40MHz and 80MHz channel width are also supported on some devices.
High Throughput(HT) mode is offered in the 802.11n standard, while Very High Throughput(VHT) mode is offered in the 802.11ac standard. 802.11ac is only available on the 5GHz band. If you have an 802.11ac capable access point, using VHT40 or VHT80 mode is recommended, as it can allow for better performance.
The 2.4Ghz band has limited available bandwidth. While it lists 11 different channels, each channel is only about 5Mhz wide. As noted above, WiFi needs a minimum of 20Mhz. This means that most of the 11 channels overlap into the same area of the radio spectrum.
For example, if you see someone already using Channel 1, and you decided to use Channel 2, you’re not actually avoiding interference from Channel 1.
The recommended channels to use on 2.4Ghz are Channel 1, 6 & 11. As can be seen in the above diagram, these channels do not overlap into each other.
In general 2.4Ghz should be considered a legacy band for older devices that do not support 5Ghz. It is often more crowded and less performant than 5Ghz.
While you can run 40MHz channel width on 2.4GHz, it is generally not recommended due to the limited total bandwidth available in the 2.4GHz band.
Lower frequencies generally travel further than higher frequency signals, so 2.4GHz may allow for further distance compared to 5GHz, but speeds will typically be significantly lower.
Open Mesh access points do not support Channels 12 - 14, and there is no planned support, as these channels are not allowed in North America.
5Ghz offers significantly more bandwidth than 2.4GHz. All of the 5GHz channels offered in CloudTrax support at least 20MHz channel width without overlap.
When using 5GHz, it is recommended to use at least 40MHz channel width, as some client devices may not prefer 5GHz unless it offers a greater channel width than 2.4GHz.
The following 5GHz channels are supported with 20MHz channel width:
If using 40MHz channel width, the following channels bandwidth is used:
- 36 - 40
- 44 - 48
- 149 - 153
- 157 -161
If using 80MHz channel width, the following channels bandwidth is used:
- 36 - 48
- 149 - 161
*Channel 165 only supports 20MHz channel width.
This means the wider the channel width used, the higher the chances that access points will overlap each other in the same radio spectrum.
If you have a sparse network with a few access points and not a lot of users, such as a home or small office, you should probably use 80MHz channel width to maximize per-client performance. Meanwhile, if you have a dense network with a lot of access points and clients, then using 40MHz channel width may help reduce the chances that access points and clients interfere with each other.
While 5GHz offers greater performance, its distance is reduced compared to 2.4GHz and it may have a harder time penetrating through some obstructions.
5GHz also offers additional channels that require Dynamic Frequency Selection(DFS). DFS allows the access point to switch channels if it detects military or weather radar already in use on the channel. This functionality is currently not supported, but we're looking into it.
Auto Channel Mode
If you do not want to manually set your own channels, you may be better served by enabling Auto Channel Mode.
For more information on which channels should be used for repeater APs on the network, see: What Channels Should Repeater APs use?