| 摘要 |
PURPOSE:To set a spare line to be switched arbitrarily, by switching a regular line and the spare line by a fast switch after selecting the spare line by a slow switch. CONSTITUTION:The spare line 1d is constituted so that it can be switched and used by switching multiple-response/multiple change-over switches provided in a specific user 2, a specific large user 2A, and an exchange center 10. In the specific user 2, the multiple-response/multiple change-over switch 31 of a ratio of (n1):(m) is provided, and a line in which a fault is generated is connected and used to either (m) spare lines 1d out of (n1) lines of the specific user 2. Also, the spare line 1d is folded in U-shape at the part of the switch 31 generally, however, at the time of generating the fault, it is separated, and is connected and used to a specific user 2 side via the switch 31. |
