| 摘要 |
PROBLEM TO BE SOLVED: To immediately start another kind of communication by stopping the transmission of a communication procedure signal when a busy tone is detected through a line within the transmission period of the communication procedure signal after calling is executed to an opposite party and the line is connected and immediately opening the line. SOLUTION: When the polarity inversion of the line L is detected after calling is executed by dialling by NCU 2 and the line L is connected to the opposite party, the detection of the communication procedure signal is started. CNG (calling tone) is transmitted till the signal is detected, the transmission and the operation of signal detection are continued till a previously fixed time elapses but the line L is disconnected when the time elapses and becomes out. Besides, when the busy tone is detected during continuing a CNG transmission processing, the transmission of CNG is stopped and the line L is disconnected by NCU 2. Thus, another kind of communication such as re-calling can be immediately started.
|
