The control mode of radio's power level.
Auto means radio chooses the feat power level automatically on the basis of the detectted circumambienceis of the wireless signal in itself;
Fixed means radio uses the power level as the configuration of administrator.
Notes: The auto mode is recommended thanks to the changeful working circumambienceis of the radio wireless signal.
If it uses the fixed mode, must detect the working circumambienceis of the radio wireless signal for the ap fristly,
then choose the feat power level, otherwise the wireless signal maybe coflict and it would make worse to the quality of the communication.