Patent ID: 7020209

Claim:
A data transmission method that puts variable length transmitted data into frames of a fixed time length and transmits these frames, comprising the steps of: at a transmitting side, calculating an error-detecting code of the transmitted data, frame by frame; generating frame data containing the transmitted data and the calculated error-detecting code such that the error-detecting code is arranged after the corresponding transmitted data; and transmitting the generated frame data, and at a receiving side, receiving the frame data; assuming the transmitted data and the error-detecting code by assuming a final bit position of the frame data, frame by frame, for the received frame data and calculating the error-detecting code of the assumed transmitted data; deciding that among the assumed final bit positions of the frame data, a position where the assumed error-detecting code agrees with the error-detecting code calculated on the basis of the assumed transmitted data is the final bit position of the frame data; and acquiring the transmitted data on the basis of a decision result, wherein at the transmitting side, if the number of bits of the transmitted data is zero, said step of calculating the error-detecting code considers a previously-specified bit pattern to be the error-detecting code, and at the receiving side, said step of calculating the error-detecting code also assumes a position where the number of bits of the transmitted data becomes zero as the final bit position of the frame data, and if the error-detecting code when the position where the number of bits of the transmitted data becomes zero is assumed as the final bit position of the frame data agrees with said previously-specified bit pattern, said step of deciding decides that the position where the number of bits of the transmitted data becomes zero is the final bit position of the frame data.