Patent ID: 7123830
Filing Date: 2006-10-17
Classification: H04J,H04Q

Abstract:
1. In a WDM (Wavelength Division Multiplexing) bidirectional self-healing optical ring network having an outer ring and an inner ring for transmission of an optical signal, a node comprising: at least one optical add/drop multiplexer having a 1×N demultiplexer and a 1×N multiplexer; a pair of optical switching devices disposed at both ends of the optical add/drop multiplexer, each connected to an optical fiber link connected to the optical add/drop multiplexer; and a pair of circulators each connected between the optical add/drop multiplexer and the respective optical switching devices, each circulator having three ports, two of the three ports coupled to a corresponding optical switching device and remaining one port coupled to the optical add/drop multiplexer; wherein the optical switching device selectively switches between a bar state and a cross state depending on whether there is an optical link failure in adjacent node.