| 摘要 |
PURPOSE:To simplify a PBRST and to economize the system, by commonly using a PB dial signal receiver in both PBORT and PBRST trunks. CONSTITUTION:When a PB dial signal is transmitted at a call Ex, the signal enters a terminal T1 of an SRT via a path 1 of NW and received at a PBREC via a path 2 of the NW. The dial numeric information received is stored in a CC and the path 2 is cut off. When the CC discriminates this dial numeric information from a call to an external line, a terminal T2 of the SRT is connected to an OGT via a path 3 of the NW. The CC controls the SRT based on the dial numeric information stored and transmits a DP dial signal from the terminal T2 of the SRT via the path 3 and the OGT to an external line. When a telephone set to be called responds, the Ex is connected with switching to the OGT and a call for the both can be made. |
