Private line backup device

Abstract

Abstract PURPOSE:To attain simplicity and miniaturization of a backup device of the center side by using a PB signal as line selection control information. CONSTITUTION:The backup device 2 at the center side allows pushbutton telephone sets 3, 4 to connect a switching control section 15 of a backup device 12 of a terminal side via exchanges 10-11 by the operation of a line switching section 6 at a fault of a private line 7 to constitute two lines of a backup exchange line. Then the line number of private lines 7-9 is used as the line selection control information by the operation of the telephone set 3 or 4, and when the number, e.g., ''1'' is transmitted at the switching of the line 7, the control section 15 decodes the information of the PB signal to switch the part of the line 7 of the switching section to the exchange line side. The center side switches the part of the line 7 of the switching section 5 to the switching section 6 to change over the switching section 6 to the switching section 5. As a result, the part of the private line 7 of MODEMs 12, 13 is used via the backup line.

Inventors

• 👤 Yasuyuki Ogawa
• 👤 康之 小川

Bibliographic Details