Channel Utilization is a statistic to represent the airtime utilization of a particular frequency or channel. The higher the Channel Utilization the more traffic is being transmitted and (hopefully received and demodulated!).
There are several ways to see Channel Utilization in the AP, WLC, and Prime. WifiNigel has a very good article that shows many ways to see this statistic in his blog article HERE.
What I wanted to see was a report to track the impact of production changes such as the reduction of SSIDs and the impact of Management Frames on Channel Utilization. Cisco Prime has a nice report to gather this data although it took some digging to find it.
1.) Open Prime and Go to the Report Tab
2.) Select AP Utilization Report
3.) Select Different Options. I would suggest running two reports. One for 802.11a and one for 802.11b.
4.) Select the Customization Report Section and Get Even More Granular
5.) Review Report
As you can see the site used as an example has high Channel Utilization in the 802.11b frequency due to 8 SSIDs and a highly dense deployment with the AP(s) deployed primarily in Hallways. High Channel Utilization can impact a client’s ability to obtain a Transmit Opportunity (TxOP). 802.11 protocol is a “Listen Before Talk” protocol. If the channel is highly utilized the Transmitting Station will have a difficult time obtaining a TxOP and this will cause a delay in transmitting data. Latency sensitive applications (Such as Wireless Voice (WVoIP)) will be highly impacted. Utilization higher than 40 to 50% will potentially impact WVoIP.