A base station is disclosed. The base station includes: a service area status determination unit configured to determine status of a service area of the base station based on received signals from mobile stations; a total transmission power determination unit configured to determine status of total transmission power of the base station based on total transmission power of surrounding base stations; a transmission power determination unit configured to determine transmission power of a common control channel of the base station based on the status of the service area and the status of the total transmission power; and a transmission power setting unit configured to set the transmission power determined by the transmission power determination unit.