That is not a global setting, as it is site/network specific. All this stuff is controlled in the RF-Profiles that you have available on the Wireless config in each site. The default uses auto settings for all APs. With that amount of APs it could be useful to limit the channel width to 20MHz to help the system to find a good channel for each AP. And with 4G Internet, you likely don't need high throughput on the APs. ... View more