Wireless communication system, wireless communication method thereof, repeater devices and wireless terminal devices

Plural repeaters (1111 to 111n) are connected one another via a system bus (115), and each of which detects the state of another repeater by checking a signal transmitted over the system bus (115). When stopping the operation of home repeater (e.g., the repeater (1111)) which performs relaying process among wireless terminal devices (TA) to (TH), a secondary repeater (e.g., the repeater (1112)) set beforehand detects that the home repeater breaks down as the secondary repeater becomes unable to detect the signal over the system bus (115). The secondary repeater responds to the detection and bears the relaying process instead of the home repeater.