To improve the normal receiving probability of a re-transmission data frame, and to improve the through-put of the data transmission.

A transmission data judgement processing part 11 of transmission side communication equipment 2a judges whether or not reception side communication equipment 2b issues a re-transmission request based on ARQ control information 5 of a feedback data frame 7 processed by a reception ARQ data frame processing part 14 of a receiving part 17. When the ARQ control information 5 is the re-transmission request, the number of times of continuous transmission of the data frame 7 being the target of the re- transmission request is decided, and the re-transmission data frame 7 and the number of times of continuous transmission are noticed to a transmission ARQ data frame processing part 10, and the data frame 7 to be re-transmitted is continuously transmitted from an ARQ transmitting module buffer 12 through the transmission ARQ data frame processing part 10.