| 摘要 |
PURPOSE:To obtain an optical relay system with simple constitution and high reliability by combining lines having a transposition function and devising the system such that the line having a loopback function is able to be reached to a line having a loopback function of any repeater from all lines of all repeaters. CONSTITUTION:Except lines comprising a standby line 10 and active lines 11-1n with a loopback function among repeaters 21-2m have a transposition function able to be connected in 2-way with other lines in a replaceable way. That is, each line for a repeater without any loopback function is connected to a line having a loopback function of any repeater through the transposition function and the test of loopback at a repeater without any line loopback function is executed by looping back the line. |
