| 摘要 |
PURPOSE:To freely constitute an alternate route through a spare transmission line, and to improve reliability by selecting the switching condition of a switch corresponding to the occurrence position of trouble. CONSTITUTION:For instance, in the case where the trouble occurs in a repeater (RRP) 52, the alternate route excluding the trouble occurrence position of a mark 'X' is constituted as shown by a thick full line by performing the switching by the switch 412, and the transmission of a signal through the spare transmission line 3 is secured. Besides, in the case where the trouble occurs in the RRP 72 of a repeating installation (REP) 7 inserted next the REP 6 as well in addition to the RRP 52, the similar alternate route is constituted through living lines 1, 2 by performing the switching of the switches 611, 613, too. The alternate route is constituted in such a way by switching the switches corresponding to the occurrence of the trouble in the living transmission line. Thus, the reliability is extremely improved. |
