| 摘要 |
PROBLEM TO BE SOLVED: To provide a repeater (1, 2, ..., N) that enables both the bi-directional optical time domain reflectometry (OTDR) technique and the loop gain monitoring technique that may be employed in particularly long repeater spans.SOLUTION: In one embodiment, the repeater (1, 2, ..., N) includes high loss loopback (HLLB) paths (202, 204) configured to couple test signals between incoming and outgoing fiber paths. The HLLB paths (202, 204) are coupled from outputs to inputs of amplifiers (A, B) within the repeater and couple both an OTDR signal and a loopback signal from an outgoing fiber path to an incoming fiber path so that the test signals may be returned to line monitoring equipment that has transmitted the test signals. |
