Abstract—Wavelength is one of the most important resourcesin Wavelength Division Multiplexing(WDM) networks.In optical routing, we are given a set of communicationpaths (or ligthpaths) in a WDM network and we mustassign a wavelength to each path so that paths sharing a linkmust be assigned with different wavelengths. By properlychoosing a set of nodes that are equipped with wavelengthconverters, the number of wavelengths which is requiredto support all lights paths can be reduced. In this paper,we study the problem of placing the minimum numberof wavelength converters in a network to ensure that thenumber of wavelengths needed will not exceed a given bound®L, where L is the maximum link load in the network and ®is a parameter defined by the network designer to reflect theoverall availability of wavelength resources. This problem,however, is proved to be NP-hard. Hence we develop anefficient heuristic algorithm for the problem and extensivetheoretical analysis and experimental studies are carried outto verify the effectiveness and performance of the algorithm.

Index Terms—wavelength converter, optical network, placement,optimization, wavelength

Cite: Can Fang and Chor Ping Low, "A Flexible Wavelength Converter Placement Scheme for Guaranteed Wavelength Usage," Journal of Communications, vol. 2, no. 1, pp. 34-43, 2007.