A control method of an air conditioner system which comprises one or more wireless communication network groups each comprising an outdoor unit and a plurality of indoor units, the method comprising: receiving, by one of an outdoor unit and a plurality of indoor units which belong to a particular group, an auto address setting command or an auto communication channel setting command; transmitting, by the outdoor unit belonging to the particular group, a channel scan start command to the plurality of indoor units belonging to the particular group; performing a channel scan by each of the outdoor unit and the plurality of indoor units; transmitting, by the plurality of indoor units, channel scan results to the outdoor unit; determining, by the outdoor unit, a channel for use of the particular group based on a result of a channel scan performed by the outdoor unit and the channel scan results received from the plurality of indoor units; and outputting, by the outdoor unit, information on the determined channel to the plurality of indoor units; wherein the determining of a channel for use comprises, when there is only one channel having a load occupancy rate of 0%, determining that the channel having the load occupancy rate of 0% is the channel for use, wherein the determining of a channel for use comprises, when there is a plurality of channels having a load occupancy rate of 0%, determining that a channel with a greatest difference in a load occupancy rate from an adjacent channel from among the plurality of channels having the load occupancy rate of 0% is the channel for use, wherein the determining of a channel for use comprises, when there is no channel having a load occupancy rate of 0%, determining that a channel having a lowest load occupancy rate due to other device not included in the air conditioner system is the channel for use. receiving, by one of an outdoor unit and a plurality of indoor units which belong to a particular group, an auto address setting command or an auto communication channel setting command; transmitting, by the outdoor unit belonging to the particular group, a channel scan start command to the plurality of indoor units belonging to the particular group; performing a channel scan by each of the outdoor unit and the plurality of indoor units; transmitting, by the plurality of indoor units, channel scan results to the outdoor unit; determining, by the outdoor unit, a channel for use of the particular group based on a result of a channel scan performed by the outdoor unit and the channel scan results received from the plurality of indoor units; and outputting, by the outdoor unit, information on the determined channel to the plurality of indoor units; wherein the determining of a channel for use comprises, when there is only one channel having a load occupancy rate of 0%, determining that the channel having the load occupancy rate of 0% is the channel for use, wherein the determining of a channel for use comprises, when there is a plurality of channels having a load occupancy rate of 0%, determining that a channel with a greatest difference in a load occupancy rate from an adjacent channel from among the plurality of channels having the load occupancy rate of 0% is the channel for use, wherein the determining of a channel for use comprises, when there is no channel having a load occupancy rate of 0%, determining that a channel having a lowest load occupancy rate due to other device not included in the air conditioner system is the channel for use.