| 摘要 |
PROBLEM TO BE SOLVED: To transmit a signal between a station connected to an ISDN line to which power is not supplied and a line terminating device with a simple configuration. SOLUTION: A station 2 does not supply power on a line 1; and in a line terminating device 3, a power unit 12 supplies power to a communication control circuit network 10 and a signal processing part 8. An open/close switch SW1 is provided on a power line 13 reaching the signal processing part 8; and at the time of originating a call, the open/close switch SW1 is closed and the signal processing part 8 is started, and a training pattern in sent to the station 2 to start prescribed signal transmission. |
