| 摘要 |
PURPOSE:To enable digital exchange operation with the synchronizing system and line concentrator only provided with the main body, by providing the exchange control circuit every individual terminal and applying optical transmission. CONSTITUTION:Audio is coded with the A/D conversion and fed to the optical transmitter via the selector 1 and also fed to the line concentrator via the optical HYB. In the reception of audio signal, the channel to be received is recognized with the control 1 with the control signal in advance, and when it is received at the optical receiver via the optical HYB for the channel to be received, it is fed to the control 1. The channel is fed to the D/A converter D/A CONV to be demodulated into analog audio. |
