Abstract: This paper introduces and analyzes the working principles and limitations of traditional optical fiber online monitoring systems. It also proposes a new optical fiber monitoring system based on idle transmission ports. It provides a detailed description of the key technologies, implementation method and actual results as well as an in-depth explanation of the core components and working principles of the new system. The proposed system utilizes the idle transmission ports of the existing transmission equipment in the communication equipment rooms to monitor optical signal transmission and reception, which eliminates the need for additional fault nodes and poses no safety hazards to safe railway operation. The real-time acquisition, processing and display of optical power data allows the accurate monitoring of the performance of optical fiber links and the timely identification of issues and provision of fault judgments, which provides an effective solution for the stable operation of optical fiber communication lines.

Key words: railway optical communication, online monitoring system, dynamic monitoring, optical fiber cable, communication optical fiber

摘要： 介绍分析传统光纤在线监测系统的工作原理和不足，提出一种基于传输空端口的光纤监测系统，详细阐述其中的关键技术、实现方式以及实现效果，深入探讨其核心组成部分及其运作原理。新系统利用通信机房既有传输设备的空闲传输端口进行光信号的收发监测，无需增加额外故障节点，对铁路安全行车不构成安全隐患，通过对光功率数据的实时采集、处理和显示，能够准确监测光纤链路的性能，及时发现问题并进行故障判断，为实现光纤通信线路的稳定运行提供有效解决方案。

关键词: 铁路光通信, 在线监测系统, 动态监测, 光缆, 通信光纤