| 摘要 |
PURPOSE:To resend an accurate image signal efficiently when the image signal has an error in transmission, by dividing transmission line bands for the output signal of a transmitter and an answer signal from a receiver. CONSTITUTION:A fame generated by a frame generation part 2 is modulated successively by a high-speed modem part 3 and applied to a high-speed modem part 8 on a reception side through hydrid circuits 6 and 7. A frame check part 9 checks whether the received frame has an error or not and when the error is detected, a reception and transmission control part 11 generates and applies an answer signal, containing a frame number, to a low-speed modem part 12, so that it is further applied to a low-speed modem part 5 on a transmission side through the hybrid circuits 7 and 6. Consequently, a transmission control part 4 reads frames, following the error-detected frame stored in the frame generation part 2, out of the memory successively to resend them through the high-speed modem part 3. |
