A master station performing continuous operations is communicatively coupled with a plurality of remote stations performing intermittent transmission/receiving operations in constant cycles. Control units of the remote stations control radio communication devices to transmit synchronizing signals to the master station in constant cycles respectively. When the synchronizing signals are received from the remote stations, a control unit of the master station acquires information of corresponding intermittent receiving timing from a memory device, and controls a radio communication device to perform transmitting operations to the remote stations in coincidence with the intermittent receiving timing. Further, the control unit of the master station reads random number values from a random number generator in re- transmission of data, and shifts data transmission timing from original timing by time corresponding to the random number values. On the other hand, the control units of the remote stations read random number values from random number generators in re-receiving of the data, and shift data receiving timing from original timing by time corresponding to the random number values. Thus, the data collision probability is reduced.
展开▼
