| 摘要 |
PROBLEM TO BE SOLVED: To improve a degree of relief against a fault of a transmission line bridged between two different link type networks by providing a cross connect section that connects and sets an optional time slot of a low-degree group line to an optional line of a low-degree group through loopback. SOLUTION: A cross connect section 5 is provided with a hair pin cross connect function that is a function connecting an optional time slot of a low- degree group line to an optional line of a low-degree group by adding a hair pin drop table 52 to the section 5. The hair pin cross connect function is used to connect directly an optical multiplex transmitter B of a ring type equipment A and an optical multiplex transmitter D of a ring type equipment B with a transmission line 3. Thus, even on the occurrence of a fault in an optical transmission line 2 between optical multiplex transmitter E, C, the transmission line 3 maintains a PATH line (shown in one-dashed chain lines) between the optical multiplex transmitters F, B and a degree of relief against a fault of a line is improved. |
