Patent ID: 11916659
Assignee: MITSUBISHI ELECTRIC CORPORATION
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 10:
11. A searching method comprising:
receiving optical signals by time division from a plurality of subscriber-side devices;
monitoring the received optical signals, and detecting a state in which the optical signals are received for a predetermined period or longer as abnormal light emission in which the optical signals from one or more of the subscriber-side devices are not received;
sequentially selecting a subscriber-side device one at a time from the plurality of subscriber-side devices other than the one or more subscriber-side devices as a target subscriber-side device, and testing whether or not the abnormal light emission is resolved by stopping transmission of the optical signal from each target subscriber-side device; and
if the abnormal light emission is resolved, specifying the target subscriber-side device being tested as a causative subscriber-side device, the causative subscriber-side device being a subscriber-side device that is a source of the abnormal light emission.