ADTRAN Holdings, Inc.
Systems and methods for identifying rogue optical network units in optical networks with wavelength-division multiplexing

Abstract:

A system identifies rogue optical network units (ONUs) on a passive optical network that uses time and wavelength division multiplexing. An optical line terminal (OLT) is configured to recognize the occurrence of errors on the upstream transmission over the network. When those errors reach a predetermined threshold, the OLT attempts to identify potential rogue ONUs by controlling the ONUs to tune to different wavelengths. The OLT first controls the ONUs to transmit on a first wavelength. The OLT then iteratively divides the ONUs into multiple groups, each group being assigned a different wavelength for upstream transmission. The OLT them monitors upstream transmission to determine which group of ONUs is exhibiting rogue behavior. This process is repeated until a small group of ONUs is isolated as a potential rogue. The potentially rogue ONUs are individually analyzed and one or more ONUs is positively identified. The system then tunes the rogue ONUs to one or more isolated channels so as not to interfere with communication by other ONUs.