Patent ID: 7684696

Claim:
A method for determining the viability of a signal path of a wavelength through a communication network, comprising: defining a performance matrix by identifying at least one performance metric describing the signal quality of the wavelength along the signal path; identifying a unidirectional path of the wavelength through a plurality of nodes interconnected by segments of optic fibre; calculating an initial value of the performance matrix by analyzing interference effects on the wavelength; for each of the plurality of nodes along the unidirectional path, identifying a downstream segment on the unidirectional path, and recalculating a value of the performance matrix by analyzing interference effects on the wavelength in the downstream segment, and analyzing interference effects on the wavelength at the node; and for each segment entering the downstream node connected to the downstream segment on the wavelength other than the downstream segment on the unidirectional path, recalculating the value of the performance matrix by identifying a transmitter node of the segment entering the downstream node on the wavelength, and analyzing interference effects on the wavelength while the signal passes through the transmitter node to the segment entering the downstream node; at a receiver node, comparing the value of the performance matrix against an acceptable threshold to determine the viability of the signal path; wherein analyzing interference effects on the wavelength comprises identifying at least one optical effect that impacts the viability of the signal path, identifying at least one dominant source contributing to each identified optical effect, and identifying at least one base variable upon which each identified dominant source depends, wherein the at least one identified base variable is one or more of the fibre type, the length of the segment, the number of wavelength, the length for each fibre span within the segment, the power level input into each span.