System and apparatus for a carrier class WDM PON providing trunk protection with increased fiber utilization, distance and bandwidth

摘要

A Passive Optical Network (PON) is provided with trunk protection by employing Wavelength Division Multiplexer (WDM) elements in combination with optical couplers at distribution nodes (DN) intermediate a pair of Local Exchange Office Nodes and a customer node. The Local Exchange Office Nodes (LEON) transmitting and receiving signals on an optical fiber loop pair through a WDM with one LEON active and one backup until a failure or cable cut occurs. Each DN drops one wavelength from the downstream loop with an AD/DRWDM and employs an Optical-Electrical-Optical (OEO) repeater to amplify the downstream signal and an OEO to amplify the upstream signal before insertion onto the upstream loop by the AD/DRWDM. The DN incorporates a second WDM for multiplexing the signals from and into the OEOs and connecting through an optical coupler to multiple user nodes.