| 摘要 |
PURPOSE:To facilitate the extensity of the whole system through a simple constitution by adding voice signals by a talking device and allowing a controller to synchronize frames and control a common line signal and communication channels. CONSTITUTION:The controller 11 allots communication channels on which talking devices 2a-2c communicate with optional calling devices through transmission lines 1 (1a-1e) and reports the channels. The devices 2a-2c receives the common line signal for specifying the communication channels of calling from the controller 11 to select the communication channels allotted individually to their stations and opposite stations respectively, and add voice signals in the allotted communication channels of the opposite subscribers to their station transmit voice signals to send the resulting signals to the communication channels; and the voice signals in the communication channels allotted to their stations are fetched respectively and the contents are substituted by an analog zero-level signals and sent out. Thus, a conference among the talking devices is realized. |
