The objective of the invention is to improve the communication performance of a secondary system within such a range that does not affect a primary system. A wireless communication system comprises: a primary system that can use a given frequency on a priority basis; secondary wireless communication systems each of which is operated with the same frequency; and a network control apparatus that controls the secondary wireless communication systems. The network control apparatus comprises: a primary system information acquiring unit that acquires information of the primary system; a secondary system information acquiring unit that acquires communication quality information of the secondary wireless communication systems; and an optimum computing unit that calculates, on the basis of the primary and secondary system information acquiring units, the transmission powers of a plurality of base stations of the secondary wireless communication systems.