A resource allocation apparatus in a communication system includes an identification unit configured to identify a new frequency band for transmission and reception of data between a plurality of terminals and a first access point, and identify a first frequency band which is being used by a second access point in the new frequency band; a setting unit configured to divide the new frequency band into sub bands of a basic frequency band, and set priorities of the sub bands; and an allocation unit configured to allocate the sub bands in correspondence to the priorities, for transmission and reception of data between the plurality of terminals and the first access point.