Wavelength assignment in an optical WDM network
The path selection and wavelength assignment to a selected path are performed by mapping the wavelength reach to the demand distribution (agile reach) resulting in a 50-60% increase in the network reach. The network reach is further increased (about 2.2 times) when on-line measured performance data are used for path selection and wavelength assignment. The connections may be engineered/upgraded individually, by optimizing the parameters of the entire path or of a regenerator section of the respective path. The upgrades include changing the wavelength, adjusting the parameters of the regenerator section, controlling the launch powers, mapping a certain transmitter and/or receiver to the respective wavelength, selecting the wavelengths on a certain link so as to reduce cross-talk, increasing wavelength spacing, etc.
1. A method of optimizing connections in a wavelength switched optical network, comprising:
determining a reach-wavelength correspondence for all wavelengths available for transporting user signals in said network and storing said correspondence in a wavelength performance database;
measuring a performance parameter for each wavelength available in said network and storing said measured performance parameter in a measurement database, together with link and wavelength identification information, wherein said measuring further comprising, for each node of said network:
determining all free wavelengths that are not used for live traffic exiting said node;
for each said free wavelength, setting up a test connection between a transmitter at said node and a next receiver; and
measuring said performance parameter for all said test connections; and
assigning a set of wavelengths to a path according to said correspondence and said measured performance parameter.
2. A method as claimed in claim 1 , further comprising storing said performance parameter in a measurement database.