Patent ID: 6249510
Filing Date: 2001-06-19
Classification: H04J,H04Q

Abstract:
A two-fiber bi-directional ring network comprisinga plurality of optical nodes interconnected to form a ring network by first and second optical transmission fibers such that information is transported over the first and second fibers in opposite directions, in which first and second groups of transmission channels in said first fiber are respectively designated service and protection channels and in which corresponding first and second groups of transmission channels in said second fiber are respectively designated protection and service channels, andwhereineach of said nodes includes apparatus that, responsive to a notification that one of said first and second fibers connected to an output port of the respective one of said nodes has failed, switches the service group of channels of the failed fiber to the other one of said first and second fibers as the protection channels for the latter fiber without having to convert those service channels to said protection channels as a result of said correspondence.