A technology for realizing real-time frequency hopping in an environment containing a plurality of masters. A game machine includes a plurality of communication modules which carry out the frequency hopping, and a control section which controls communication by the communication modules. The control section controls the frequency hopping of at least one communication module to prevent frequency channels used by the plurality of communication modules from temporally overlapping. As a method for achieving the control, for example, a frequency band may be divided, and a divided frequency band may be assigned to each communication module. Alternatively, each communication module may use the same reference hopping pattern by shifting its phase, or may use the reference hopping pattern by adding a predetermined offset.