A wireless communication system, comprising a master terminal and a plurality of slave terminals, in which transmission and reception of first and second wireless signals are performed between the master terminal and each slave terminal, using a radio wave as a medium, wherein the master terminal comprises: a first transmitter configured to transmit the first wireless signal; a first receiver configured to receive the second wireless signal; and a first controller configured to control the first transmitter and the first receiver, wherein each slave terminal comprises: a second transmitter configured to transmit the second wireless signal; a second receiver configured to receive the first wireless signal; and a second controller configured to control the second transmitter and the second receiver, wherein the second controller is configured to control the second transmitter to transmit the second wireless signal on a frequency channel that is selected from a plurality of frequency channels previously provided, and control the second receiver to receive the first wireless signal on the selected frequency channel, wherein the first controller is configured to determine presence or absence of reception of the second wireless signal while sequentially changing a present frequency channel to be selected in the plurality of frequency channels; characterized in that each of the first and second wireless signals comprises a frame that includes: a preamble for establishing bit synchronization; and a unique word for establishing frame synchronization, and wherein the first controller is configured to: determine the presence of the reception of the second wireless signal on the present frequency channel, if the frame synchronization is established before a prescribed period elapses after the bit synchronization is established for the radio wave received by the first receiver, and further continue the reception of the second wireless signal on the present frequency channel; and determine the absence of the reception of the second wireless signal on the present frequency channel, if the frame synchronization is not established before the prescribed period elapses, and further change the present frequency channel to a subsequent frequency channel. a first transmitter configured to transmit the first wireless signal; a first receiver configured to receive the second wireless signal; and a first controller configured to control the first transmitter and the first receiver, wherein each slave terminal comprises: a second transmitter configured to transmit the second wireless signal; a second receiver configured to receive the first wireless signal; and a second controller configured to control the second transmitter and the second receiver, a second transmitter configured to transmit the second wireless signal; a second receiver configured to receive the first wireless signal; and a second controller configured to control the second transmitter and the second receiver, wherein the second controller is configured to control the second transmitter to transmit the second wireless signal on a frequency channel that is selected from a plurality of frequency channels previously provided, and control the second receiver to receive the first wireless signal on the selected frequency channel, wherein the first controller is configured to determine presence or absence of reception of the second wireless signal while sequentially changing a present frequency channel to be selected in the plurality of frequency channels; characterized in that each of the first and second wireless signals comprises a frame that includes: a preamble for establishing bit synchronization; and a unique word for establishing frame synchronization, and wherein the first controller is configured to: determine the presence of the reception of the second wireless signal on the present frequency channel, if the frame synchronization is established before a prescribed period elapses after the bit synchronization is established for the radio wave received by the first receiver, and further continue the reception of the second wireless signal on the present frequency channel; and determine the absence of the reception of the second wireless signal on the present frequency channel, if the frame synchronization is not established before the prescribed period elapses, and further change the present frequency channel to a subsequent frequency channel. determine the presence of the reception of the second wireless signal on the present frequency channel, if the frame synchronization is established before a prescribed period elapses after the bit synchronization is established for the radio wave received by the first receiver, and further continue the reception of the second wireless signal on the present frequency channel; and determine the absence of the reception of the second wireless signal on the present frequency channel, if the frame synchronization is not established before the prescribed period elapses, and further change the present frequency channel to a subsequent frequency channel.