| 摘要 |
<p>PURPOSE:To cause difficulty in voice reproduction with communication channels and to secure the secret of communication by multiplying a PCM voice signal data of respective subscriber's circuits and a control signal data after separation into bit units and transmitting them through the communication channels. CONSTITUTION:An interface circuit 1 re-synchronizes respective received subscriber's circuit frame signals by a clock signal, the respective subscriber's circuit frame signals synchronized with frame pulses are repeatedly transmitted by 0th bit to 256th bit successively to be stored in a buffer circuit 2. A multiplex circuit 3 reads the subscriber's circuit frame signal stored in the buffer circuit 2, adds a 0th bit frame signal F, and converts the 0th bit data of respective subscriber's circuit frame signals from the 8th bit in series successively. Thus, the voice signal for the 8 subscriber circuits from #0 to #7 and a multiplex frame signal multiplexing the control signal are generated, and transmitted through an E/O circuit 4 to the subscriber's circuit.</p> |
