An air conditioner system which comprises a plurality of units comprising at least one outdoor unit and a plurality of indoor units, wherein each of the plurality of units comprises a wireless communication module and the plurality of units are located in a plurality of spaces, the wireless communication module being configured to perform wireless communication using a Sub-GHz frequency band, characterized in that: the wireless communication module comprises: an encoder configured to encode a predetermined signal; a modulator configured to modulate the encoded signal according to Orthogonal Frequency Division Multiplexing, OFDM, using multiple subcarriers; at least one antenna having an antenna pattern formed in a Printed Circuit Board, PCB, and configured to output a signal based on the modulated signal; a demodulator configured to demodulate a signal, received from the at least one antenna, according to the OFDM; and a decoder configured to decode the demodulated signal, and wherein the wireless communication module is adapted to perform communication by a different communication method according to a target unit to communicate, by selectively changing the communication method in response to the target unit to communicate; wherein the wireless communication module of a first unit among the plurality of units is configured to: communicate using a first wireless communication method when communicating with a second unit disposed in a first space, and communicate using a second wireless communication method different from the first wireless communication method when communicating with a third unit disposed in a second space different from the first space, wherein the first wireless communication method is a wireless communication method using a first channel corresponding to the second unit in 900MHz frequency band, wherein the second wireless communication method is a wireless communication method using a second channel corresponding to the third unit in the 900 MHz frequency band, the second channel being different from the first channel. an encoder configured to encode a predetermined signal; a modulator configured to modulate the encoded signal according to Orthogonal Frequency Division Multiplexing, OFDM, using multiple subcarriers; at least one antenna having an antenna pattern formed in a Printed Circuit Board, PCB, and configured to output a signal based on the modulated signal; a demodulator configured to demodulate a signal, received from the at least one antenna, according to the OFDM; and a decoder configured to decode the demodulated signal, and wherein the wireless communication module is adapted to perform communication by a different communication method according to a target unit to communicate, by selectively changing the communication method in response to the target unit to communicate; wherein the wireless communication module of a first unit among the plurality of units is configured to: communicate using a first wireless communication method when communicating with a second unit disposed in a first space, and communicate using a second wireless communication method different from the first wireless communication method when communicating with a third unit disposed in a second space different from the first space, wherein the first wireless communication method is a wireless communication method using a first channel corresponding to the second unit in 900MHz frequency band, wherein the second wireless communication method is a wireless communication method using a second channel corresponding to the third unit in the 900 MHz frequency band, the second channel being different from the first channel. communicate using a first wireless communication method when communicating with a second unit disposed in a first space, and communicate using a second wireless communication method different from the first wireless communication method when communicating with a third unit disposed in a second space different from the first space, wherein the first wireless communication method is a wireless communication method using a first channel corresponding to the second unit in 900MHz frequency band, wherein the second wireless communication method is a wireless communication method using a second channel corresponding to the third unit in the 900 MHz frequency band, the second channel being different from the first channel.