A wireless communication system comprising: a master terminal and slave terminals, which are configured to perform wireless communication with each other in accordance with a time division multiple access protocol, wherein the master terminal comprises: a first transmitter configured to transmit a wireless signal; a first receiver configured to receive a wireless signal; and a first controller configured to control the first transmitter and the first receiver, and each of the slave terminals comprises: a second transmitter configured to transmit a wireless signal; a second receiver configured to receive a wireless signal; and a second controller configured to control the second transmitter and the second receiver, wherein each of the master and slave terminals (1 and 10) is configured to transmit and receive wireless signals on a superframe basis, the superframe being composed of first and following frames ( 1 st and 2 nd to 30 th), each frame of the superframe consisting of a plurality of time slots, wherein the first frame ( 1 st) comprises: a downlink slot, comprising a synchronizing signal, from the master terminal to the slave terminals; and uplink slots ( D 1 to D m), pre-allocated to respective slave terminals, from the slave terminals to the master terminal, wherein the first controller is configured to control the first transmitter to divide the downlink slot into a plurality of transmitting segments ( tsg1 to tsgx) with the synchronizing signal contained in a segment signal of each of the transmitting segments ( tsg1 to tsgx) and also to sequentially transmit the segment signals of the transmitting segments (tsg1 to tsgx) on respective different frequency channels (ch1 to chx), said segment signal being a wireless signal transmitted during each of the transmitting segments ( tsg1 to tsgx) in the downlink slot and a second controller of each of the slave terminals is configured to control a second receiver corresponding to the second controller to receive the segment signal on a variable frequency channel selected from said different frequency channels (ch1 to chx). a master terminal and slave terminals, which are configured to perform wireless communication with each other in accordance with a time division multiple access protocol, wherein the master terminal comprises: a first transmitter configured to transmit a wireless signal; a first receiver configured to receive a wireless signal; and a first controller configured to control the first transmitter and the first receiver, and a first transmitter configured to transmit a wireless signal; a first receiver configured to receive a wireless signal; and a first controller configured to control the first transmitter and the first receiver, and each of the slave terminals comprises: a second transmitter configured to transmit a wireless signal; a second receiver configured to receive a wireless signal; and a second controller configured to control the second transmitter and the second receiver, a second transmitter configured to transmit a wireless signal; a second receiver configured to receive a wireless signal; and a second controller configured to control the second transmitter and the second receiver, wherein each of the master and slave terminals (1 and 10) is configured to transmit and receive wireless signals on a superframe basis, the superframe being composed of first and following frames ( 1 st and 2 nd to 30 th), each frame of the superframe consisting of a plurality of time slots, wherein the first frame ( 1 st) comprises: a downlink slot, comprising a synchronizing signal, from the master terminal to the slave terminals; and uplink slots ( D 1 to D m), pre-allocated to respective slave terminals, from the slave terminals to the master terminal, the first controller is configured to control the first transmitter to divide the downlink slot into a plurality of transmitting segments ( tsg1 to tsgx) with the synchronizing signal contained in a segment signal of each of the transmitting segments ( tsg1 to tsgx) and also to sequentially transmit the segment signals of the transmitting segments (tsg1 to tsgx) on respective different frequency channels (ch1 to chx), said segment signal being a wireless signal transmitted during each of the transmitting segments ( tsg1 to tsgx) in the downlink slot and a second controller of each of the slave terminals is configured to control a second receiver corresponding to the second controller to receive the segment signal on a variable frequency channel selected from said different frequency channels (ch1 to chx).