| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem in which, since, conventionally, normality of an optical switch is determined by comparing optical reception levels of a normal system OSU and a preliminary system OSU, even when the optical switch is erroneously connected, the connection is erroneously determined as being normal.SOLUTION: The station side communication apparatus includes an optical switch failure diagnosis part for performing an optical switch failure diagnosis by comparing specific information of a slave station communication apparatus extracted from an upstream reception frame at a preliminary station side interface unit and specific information of a slave station side communication apparatus connected to a normal station side interface unit. |
