| 摘要 |
PROBLEM TO BE SOLVED: To prevent crosstalk by transmitting a down signal through a first electric line, sending it through an electric transmission line to the terminal equipment, distributing/branching an up signal to the second electric connection line and transmitting it through a channel being not used. SOLUTION: An electric signal to be transmitted through an electric transmission line EL to the side of terminal equipment is received through branchers 28 and 30 to respective terminals T1 and T2. Then, the electric signal distributed to the side of second electric connector CL2 by a brancher 26 is converted to an optical signal by an electric/optic converter 24 and that optical signal is propagated through a second optical transmission line OL 1 to the side of center equipment 10. In this case, on the transmission lines OL 1, the signals of even-numbered channels are valid as up signals and the signals of odd- numbered channels can be regarded as the return signals of signals transmitted from the center equipment 10. Since the same frequency band is not shared between up signals and down signals, the radio interference of signals is not generated. |
