C9117AXI-H Power Level can not set to datasheet guaranteed

[AstralVoyager]

Hi guys recently I have an issue. C9117AXI-H power level can not set to datasheet's guaranteed value.

Is it a configuration issue? Currently using C9800-CL with it. When I use EWC mode + power level 1, it can be set to 25dBm. But I compared, when the AP run in EWC mode, speed much slower and signal gets bad....

And as per datasheet, it will run all features except USB power output with 802.3at(PoE+). I checked mine it is working at AT mode (25.5W power max)

It really confused me... Could someone help? That'd be much appreciated

[Scott Fella]

What you are seeing is max TX power, but that is dynamically adjusted per regulatory regulations.  If you look at the Transmit power and receive sensitivity in this document, you can see what the max power level for the AP, but you also have to know what the max TX power is in your country as that can be different along with the channel width you use.  Also max TX power is typically for outdoor not indoor.
https://www.cisco.com/c/en/us/products/collateral/wireless/catalyst-9100ax-access-points/datasheet-c78-741989.html

[AstralVoyager]

ahh bro thanks but when I run EWC mode with country code CN and set power level to 1, 5Ghz indeed showed 25dbm, pretty weird scenario

[Scott Fella]

That really shouldn't be, because, like in the US, max TX for indoor on 2.4GHz is 100mW/20dBm. Keep in mind that when external antennas are used, you can obtain higher EIRP combining a higher gain antenna and TX power.  This is used in the outdoor space. Also what is important is to understand the max TX for end devices. Typically when a site survey is performed, you don't survey with the max TX power, but maybe something in the middle or even lower.  When you over power a device because you want range, the client can hear the ap, but the ap can't hear the client.  Max TX is not a good idea in an indoor space because of these client types and of course attenuation.