As per 3GPP reference 36.104 release 12, there are four classes for the base stations based on the rated power is listed below
|S.No.||3GPP Base station Class||Rated O/p Tx Power||Base Station Type|
|1||Wide Area Base Station||No Upper limited defined by 3GPP, Max power is restricted by local Regulatory||Macro Cell Base station|
|2||Medium Area Base Station||<=38 dBm for single antenna Port||Micro Cell Base station|
|3||Local Area Base Station||<= 24 dBm for single antenna Port||Pico Cell Base station|
|4||Home Base station||<=20 dBm for single antenna Port||Femto Cell Base station|
The rated power defined here is for single antenna configuration and it will be divided across antenna ports when more than one antenna is used. For example a Home Base station the max rated power is 20 dBm for one antenna, if we change the antenna configuration to 2 antenna configuration then per antenna port power will reduced to 17dBm.
Here it can be clearly seen whenever doubling the antenna port the power is reduced by 3dB (Half of the power), so for 4 antenna configuration it will be further reduced by 3dB providing 14 dBm power per antenna port and so on. Form here it can be concluded that the specification provides the max rated power and a designer need to take this in consideration while designing the power amplifier and other active elements of base station Radio.