Patent ID: 7454138
Filing Date: 2008-11-18
Classification: H04J,H04L

Abstract:
1. A path-optimizing method for use with an optical network formed by mutually connecting a plurality of optical transmission nodes for transmitting a wavelength multiplexed optical signal to a plurality of add-drop nodes for executing add-drop processing of said wavelength multiplexed optical signal, wherein said optical transmission nodes and said add-drop nodes retain, as span information, information about conditions of transmission paths between other adjacent nodes connected to said optical transmission nodes and said add-drop nodes; said span information retained in each of said nodes is cumulatively transmitted from one of said plurality of add-drop nodes, which is to be a starting-point node of a certain wavelength path, to another of said plurality of add-drop nodes, which is to be an end-point node of said wavelength path; said end-point node autonomously determines a pathway satisfying predetermined transmission conditions as a pathway optimal for said wavelength path on the basis of cumulative span information which is transmitted in connection with a plurality of pathways from said starting-point node to said end-point node; each of said add-drop nodes has an electrical regenerative relay function section selectively subjecting at least one of one or more wavelengths forming said wavelength multiplexed optical signal to electrical regenerative relay; and when the electrical regenerative relay is determined to be required according to a result of cumulative determination made by said end-point node, said end-point node effectively controls the electrical regenerative relay function section of said add-drop nodes in the pathway determined by said end-point node.