Packet data consist of preamble information, header information, transmitting information and an error detection code arranged in the order are generated to be transmitted to wireless communications apparatus. When data transmitted from the wireless communications apparatus are received, it is determined whether or not a correlation value of the received data with predetermined preamble information is equal to or larger than a predetermined threshold. When the correlation value is equal to or larger than the threshold, then it is determined whether or not there are next header information and transmitting information to be transmitted. Finally, next packet data based on the next header information and transmitting information are transmitted. Packet data will not be retransmitted even when bit error exists in a response signal, thus making it possible to improve the transmission efficiency.