Patent ID: 7286759

Claim:
A method of dynamic wavelength assignment for a requested new flow, from a source node to a destination node, in a Wavelength Division Multiplex (“WDM”) ring network having traffic on existing wavelengths, comprising the steps of: mapping a new flow and the existing wavelengths to one or more relevant cases, wherein each of the relevant cases is representative of a spatial relationship between a new flow and an existing wavelength, and the relevant cases are members of an identified set of cases defining all the possible spatial relationships for new flows and existing wavelengths; associating with each member case of the set of cases the number of Optical/Electrical (“O/E”) and Electrical/Optical (“E/O”) interfaces which would be added at nodes if a new flow were sent on a wavelength corresponding to said each member case; selecting one of the relevant cases to which the new flow and existing wavelengths have been mapped by referring to the associated numbers of O/E and E/O interfaces and identifying which of the relevant cases results in the fewest total number of optical-to-electrical (“OE”) and electrical-to-optical (“EO”) interfaces being added to the network; and selecting a wavelength corresponding to the selected one of the relevant cases, to be assigned to the new flow.