Patent ID: 7444079
Filing Date: 2008-10-28
Classification: H04B,H04J

Abstract:
1. A method of tracking and compensating for changes in a multi-channel, dense wavelength division multiplexing (DWDM) network, comprising employing a dither feedback mechanism which uses optical filters that are already part of the network for add/drop functions; dithering the center wavelength of each channel in use in the network about the center of a respective optical filter bandpass, and then passing each channel through its optical filter bandpass to obtain a measurement of the optical transfer function (OTF) in the network at any instant in real-time; generating feedback signals from said measurements; and using said feedback signals to adjust the network or the optical channels in the network to compensate for the changes in the optical channels; wherein, when the network configuration is changed by adding or dropping wavelengths, the resulting change in the OTF is tracked and said feedback signals are used to compensate for the change by adjusting the wavelengths of the optical channels in the network to maintain a defined optical transfer function in the network.