What are WiFi Channels and Widths?

WiFi radios work similarly to 2-way radios. Each Access Point has its channel set. When a client device connects to the Access Point, it is also using that channel to communicate back to the Access Point. If the channel is too busy - the Access Point will wait before transmitting data. Similar to how only one person can talk at a time using 2-way radios.

It is best practice to use channels that do not overlap with each other. This creates a less noisy environment, which should lead to better speeds on your WiFi network.

On 2.4GHz networks, there are 3 non-overlapping channels:

These channels are shown in blue (1, 6 and 11). If you have 2 adjacent Access Points - one using channel 1 and one using any channel 2-5 they will interfere with one another and have to wait for the other before sending data. If you used channel 1 and channel 6 both Access Points would be able to send/receive data simultaneously without interference.

To avoid this overlap, Meter Networks will only use channels 1, 6 and 11 on 2.4Ghz WiFi networks.

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5GHz networks also work in a similar way. However, there are more channels to use and the channel width can also be specified. Here is how the 5GHz spectrum looks:

On 5GHz channels, the amount of non–overlapping channels is dependent on the width of the channel (2.4GHz uses only 20MHz channels).

• 20MHz - 25 channels
• 40MHz - 12 channels
• 80MHz - 6 channels

In most cases the Meter Network will be using 40MHz channels (non weather radar) unless the network has a large amount of Access Points (where 20MHz may be more suitable). Or if the network has a very small number of Access Points (where 80MHz can be used).

Why does channel width matter, and how does Meter select channels?

With wider channel widths - client devices (your laptop/phone/etc) will be able to transmit more data at once. Therefore you will see faster download/upload speeds.

However, the widest channels will not always “just work”. In most cases 40MHz is used because:

• It gives us more non-overlapping channels to use. This is important because it allows us to ensure our Access Points on same channels are spaced far enough apart so that they do not interfere with one another.
• It allows us to to better work-around interference from neighboring businesses.

At every new Meter deployment, Access Points are used to scan the environment for competing signals. Using this data we are able to make informed decisions on which channel a particular Access Point should be using.