A wireless communication system in which two or more local area wireless communication networks (10a, 10b) performing wireless communication through mutually different physical layers coexist, and wireless communication is performed between a plurality of devices and a coordinator (3a, 3b) in each one of the wireless communication networks (10a, 10b), wherein the coordinator of one wireless communication network includes: a data generating unit that generates coexistence notification frame data (u_r) used for notifying coordinators of the other wireless communication networks of existence of the coordinator; an FEC encoder that encodes the coexistence notification frame data generated by the data generating unit and inserts source data before the encoding into the encoded data as source code data so as to be set as FEC data (u_re); a modulation unit that modulates the FEC data transmitted from the FEC encoder through a Gaussian frequency shifting keying system, GFSK, or a frequency shifting keying system, FSK, so as to be set as a modulated wave signal (u_resm) that all coordinators (3a, 3b) are able to extract; and a transmission unit that transmits the modulated wave signal generated by the modulation unit to the coordinators of the other wireless communication networks, where the modulated wave signal is transmitted at least once for one super frame or once for a plurality of super frames of a super frame structure of the wireless communication system, where the coordinator of any of the the other wireless communication networks is configured to receive the modulated wave signal (u resm) during a scanning period arranged before starting communication of a first super frame by the coordinator and immediately after input of power to the coordinator, where the scanning period has a period of a length that is equal to or longer than a length of the super frame of the super frame structure of the wireless communication system, and where the coordinator of the other wireless communication networks is configured to acquire the coexistence notification frame data by demodulating and decoding the received modulated wave signal and performing control for preventing communication interference with the one wireless communication network. a data generating unit that generates coexistence notification frame data (u_r) used for notifying coordinators of the other wireless communication networks of existence of the coordinator; an FEC encoder that encodes the coexistence notification frame data generated by the data generating unit and inserts source data before the encoding into the encoded data as source code data so as to be set as FEC data (u_re); a modulation unit that modulates the FEC data transmitted from the FEC encoder through a Gaussian frequency shifting keying system, GFSK, or a frequency shifting keying system, FSK, so as to be set as a modulated wave signal (u_resm) that all coordinators (3a, 3b) are able to extract; and a transmission unit that transmits the modulated wave signal generated by the modulation unit to the coordinators of the other wireless communication networks, where the modulated wave signal is transmitted at least once for one super frame or once for a plurality of super frames of a super frame structure of the wireless communication system, where the coordinator of any of the the other wireless communication networks is configured to receive the modulated wave signal (u resm) during a scanning period arranged before starting communication of a first super frame by the coordinator and immediately after input of power to the coordinator, where the scanning period has a period of a length that is equal to or longer than a length of the super frame of the super frame structure of the wireless communication system, and where the coordinator of the other wireless communication networks is configured to acquire the coexistence notification frame data by demodulating and decoding the received modulated wave signal and performing control for preventing communication interference with the one wireless communication network.