| 摘要 |
PURPOSE:To increase the effect of communication, by dividing the frequency bands of a cable circuit and performing the telephone communication while data is transmitted. CONSTITUTION:A circuit adaptor Ai is provided at an end office of a branching network set at the joint of a cable circuit to separate transmission from reception. The voltage drop compoent due to the resistance provided in series to a transmission line within the adaptor Ai is led to a circuit of the receiving side. Thus the transmitting signal of the end office is transmitted to the cable side and not led virtually to the receiving side of the own station. The receiving side has a low-pass filter BR to pass the <=1kHz signals and another low-pass filter DR to pass the signals of 10-100kHz, respectively. The frequency bands 1-10kHz and 10-100kHz are used for a carrier telephone and for the transmission of the data code, respectively. As a result, the telephone communication is possible in parallel to the data transmission for a cable circuit. |
