| 摘要 |
PURPOSE:To ensure the recalling between the subscribers by identifying the hooking of the subscriber under the talking state through the telephone exchange and then transmitting the audible tone to the subscriber of the remote side to perform exchange. CONSTITUTION:In case subscriber A and B are talking and then A leaves from the receiver with the voice of B incapable to call out A, subscriber B has hooking. Thus, intra-office trunk 4 relays the above state which is then detected at scanner 5 and then identified via common control unit 6. Then the path of subscriber A is connected to oscillator 8 which can transmit the audible tone. With generation of the audible tone, A comes back to the original place to give a voice which can be confirmed by B. With hooking of B, unit 6 releases the path. Thus, both A and B can have recalling to each other. |
