The Maximum Conductive Power/Max Transmit Power of the Access Point, (now listed in the datasheet for newer models) lists the maximum power the radios are able to transmit, without regard to regulatory restrictions.
Regulatory domains for each country mandate the maximum power that a radio can transmit in each band (per channel) through a multi-faceted formula. The actual maximum allowable output setting, per channel for each model AP, is determined during regulatory approval testing that is done per device/per country in accordance to applicable regulation values at the time of certification. If regulations change, existing devices may not be re-certified, and new devices will be certified under the new rules.
The following factors contribute to the final maximum permissible setting:
- Country of Operation
- Maximum allowable power per country regulations
Channel of operation
Antenna being used
Transmission mode, e.g. 11a,b,g, n, ac
Channel bandwidth e.g. 20Mhz, 40Mhz, 80Mhz
Out of band emissions
Power Density Limits
When in service, the AP can be configured to the maximum allowed power per channel based on its configuration variables.
The maximum power output settings also can vary between firmware versions and access point models based on the latest regulatory approval testing.