| 摘要 |
PURPOSE:To reduce the quantity of the hardware, by inserting a multiplexed switchboard cord trunk circuit to a multiplexed digital channel. CONSTITUTION:The analog signal sent from a transmitter microphone T of a switchboard POS301 receives an A/D conversion 310 and then a multiplexed MUX320 to be transmitted to a subscriber under a reception process via a sending speech level controller 331 within a switchboard cord trunk PCT330. At the same time, a digital mixture 334 is carried out between the signal sent from the subscriber under a reception process and the monitor signal sent from a subscriber under calling via the controllers 332 and 333. These mixed signals are then separated from each other by a multiplexing device 321 and according to the switchboard to be applied to a telephone receiver R of the POS301. The same process is given to both a microphone T and receiver R of a POS302. |
