| 摘要 |
PURPOSE:To prevent the effect of a network on allocating terminals and congestion rate, by applying audible tone without passing through a time division network, in an automatic exchanger having the said network allocating trunks. CONSTITUTION:A toll attendant board TB connects subscribers A and B desiring a toll call via an operator trunk OPT. A supervisory desk SP monitors a toll call via the trunk OPT and supervises the exchange of the TB. The subscribers A and B, the TB, the SP and corresponding terminals F, R, O and S of the trunk OPT are connected via paths s1-s4 of a time sharing network NW. An audible sound source TG is connected to a terminal T of the trunk OPT, an audible tone applied via a switch s7 is superimposed on the audio at the trunk OPT and applied to the subscribers A and B. Thus, the audible tone can be applied without giving effect on the allocation terminal of the network NW and the congestion rate. |
