k-weighted minimum dominating sets for sparse wavelength converters placement under nonuniform traffic

Abstract

In WDM all-optical networks, the deployment of wavelength converters improves the blocking performance. One solution is to equip every node in the network with converters (full wavelength conversion); however the cost and the technological limitations make it not practical. The alternative is to choose a subset of nodes and equip them with wavelength converters (sparse wavelength conversion). This paper makes the first known attempt to solve the sparse wavelength converters placement problem using the k-weighted minimum dominating set (k-WMDS) approach. To evaluate our proposed scheme under nonuniform traffic, we compared it against the well-known approach (referred to as k-BLK) of placing converters in nodes having the highest blocking percentage. The two algorithms were compared under different nonuniform traffic loads using network simulation with the U.S Long Haul and NSFNET topologies. For different values of the hop-distance parameter, k, the proposed k-WMDS algorithm has consistently given better blocking performance than k-BLK under the constraint that the number of converters in both algorithms is equal to the cardinality of the k-weighted minimum dominating set.