| 摘要 |
PROBLEM TO BE SOLVED: To provide a communication protocol for setting a half duplex type- data transfer link between two devices (a moving telephone and the data adapter of a computer are advantageous). SOLUTION: The link is set to a transfer mode. At that time, data to be transferred and control messages are processed between the two devices (the moving telephone 3 and the data adapter 2). The link is also set to an idle mode. At that time, the control messages (CM1, CM2, CM1' and CM2') are processed between the two devices. At the time of the idle mode, the transmission timing of the control messages is free. When the two messages CM1 and CM2 collide, namely, when they are simultaneously transmitted, CM1' and CM2' are re-transmitted after the time of different lengths. |
