A data processing unit selects either one of a base station mode and a terminal mode so as to perform communications using packet signals. The base station mode is a mode in which a packet signal, containing data indicating that an initial source and a final destination are not its own radio apparatus, is to be communicated; the terminal mode is a mode in which a packet signal, containing data indicating that the initial source or the final destination is its own radio apparatus, is to be communicated. A control unit starts the radio apparatus by setting the data processing unit in the terminal mode. When a packet signal, which has been transmitted from another radio apparatus and which contains broadcast information, has not been received before a certain period of time elapses after the start, the control unit switches the mode of the data processing unit to the base station mode.