COMMUNICATION MONITORING DEVICE, COMMUNICATION MONITORING METHOD AND OPTICAL LINE TEST SYSTEM

摘要

PROBLEM TO BE SOLVED: To easily identify a branch optical fiber to a PDS optical line without service interruption and without dependent on ONU device performance.SOLUTION: A communication monitoring device for checking a communication state between an OLT and a plurality of ONUs connected through an optical fiber transmission line includes: an optical detector unit 11 for receiving an upward optical signal from each ONU through an optical branch unit installed between the OLT and the ONU, to detect from the received signal a frame having stored ONU proper information; a power detector unit 13 for detecting the intensity of the received signal; a recorder unit 16 for temporally recording the detected frame information and the detected power; and a signal processing unit 17 for determining the ONU from the ONU proper information when the power in each of the ONU proper information varies equal to or greater than a predetermined threshold.