| 摘要 |
PURPOSE:To simplify the control at packet exchange mode communication, by inserting respectively an exchange mode switching device among each subscriber line station side terminator, a line exchange channel and a packet exchange device. CONSTITUTION:A terminal device 11 or 21 uses a signal channel 81 of a digital subscriber line and transmits a line exchange mode set signal to a composite exchange 5. A controller 11 transmits a control signal to set the channel 81 to a line exchange mode to an exchange mode switching device 9 based on the set signal and returns a line exchange mode set end signal to the terminal devices 11, 21 by using the channel 81. After each terminal device receives this end signal, the terminal device transmits a calling signal by using the channel 81 and performs communication by channel 3 after the response of the opposite terminal. After the end of communication, each terminal device transmits an exchange mode release signal to the exchange 5 and switches the exchange mode of the channel 81 to the packet exchange mode. |
