A novel highly reliable WDM-PON system

We propose and experimentally investigate a highly reliable WDM-PON system. The proposed system adopts the colorless solution. It can detect the failure of the feeder fiber by the polling and restoring mechanism of the system management module, and then trigger the OSW switching to the preplanned path for restoring the disrupted traffic, and produce a broken fiber alarm if needed. The system management module can send polling frames to ONUs periodically and judge whether it is necessary to send trigger signals to the OSW according to the number of ONUs registered in line cards. The preplanned path is the feeder fiber of the neighboring line card. This system can automatically protect against the feeder fiber failures without duplicating the feeder fiber link. The OTDR or optical power meter can be saved which is used for on-line monitoring. Its restoration time is less than 16ms in experiments.