Channel Utilization

Channel utilization shows how congested a WiFi channel is, as a percentage of its total capacity. You can view channel utilization per radio in the Access Point Radios tab.

A higher percentage indicates a busier channel, resulting in reduced throughput. The calculated value varies based on the radio frequency environment of the Access Point.

Channel utilization calculation

The channel utilization value is calculated based on these factors: 

• Transmit time (TX): how much time was used for data transmission from WiFi client to the Access Point over the last hour (in milliseconds). 
• Receive time (RX): how much time was used for data transmission from the Access Point to the WiFi client over the last hour (in milliseconds)
• Busy time: how much time was used by third parties for data transmission over the last hour (in milliseconds)
• Idle time: how much time the channel was not actively used for data transmission over the last hour (in milliseconds)

Calculation

Total Utilization= Transmit Time+Receive Time +Busy Time

Channel Utilization=(Total Utilization−Idle TimeTotal Utilization)×100Channel Utilization=(Total Utilization + Idle TimeTotal Utilization​)×100

Best practices

High channel utilization can cause a variety of problems, including slow network performance, "missing" SSIDs, network timeouts or connection issues, and dropped network packets. Therefore, it should be kept at a healthy level.

General Guideline for Channel Utilization:

• Voice traffic: Keep below 20% for clear audio.
• Video traffic: Keep below 50% for smooth playback.
• Data traffic: Keep below 75% for reliable performance.

Reducing channel utilization

High channel utilization can be caused by several factors, including:

• Too many connected clients sharing the same WiFi channel, leading to increased usage and congestion.
• Every additional SSID on the same AP radio increases channel utilization, even when not actively used.
• Interference from nearby wireless networks operating on the same channels.
• Use of overlapping channels, which are more prone to interference compared to non-overlapping ones.

High transmit and receive times indicate that the Access Point’s own radio activity is contributing significantly to channel utilization. If this is the case, consider the following:

• Reduce the number of SSIDs operating on the same radio.

• Deploy multi-radio Access Points to enable client distribution across multiple radios, thereby minimizing per-radio channel utilization.

• Deploy additional Access Points operating on multiple, non-overlapping channels.

High busy time, on the other hand, indicates that nearby wireless devices, like other Access Points or non-WiFi devices, are causing interference on the channel. If this is the case, consider the following:

• Reduce channel width as narrower channels help avoid overlap and reduce interference.
• Switch to a less congested or interference-free channel whenever possible.

High channel utilization often occurs on the congested 2.4 GHz band. If your network consists of dual- or tri-band Access Points, consider disabling the 2.4 GHz radio for a better user experience.