| 摘要 |
PURPOSE:To use a privacy telephone set in common from all subscribers of an electronic exchange, by connecting an input/output of the privacy telephone set to a trunk link network of the electronic exchange via an out-band dial signal outgoing/incoming trunk. CONSTITUTION:When a telephone set 1 makes a call, it is connected to an ORT 11, and the 1st dial number 8 reserves a path via an ODBWT8, a privacy telephone set 10 and an ODBWT9. The number dialed from the telephone set 1 passes through an OST14 and is transmitted to the incoming side of an ODBWT7 of a remote station via the outgoing side of the ODBWT7. A call tone is given from a TNT12 via the outgoing/incoming side of the ODBWT7 of both exchanges toward the opposite direction. The calling signal from an RGT13 is given to the imcoming subscriber. When the incoming subscriber responds, the path is switched to the reserved path, allowing to make privacy call between the telephone set 1 and the incoming subscriber with the privacy telephone set 10 inserted between the both. |
