A pure framework for cost-effective virtual ring based traffic grooming in WDM optical networks

This paper presents a cost-effective virtual topology design framework based on virtual rings in both ring and mesh optical WDM networks. The traffic grooming problem is solved in separate steps, in which different objectives are considered. The nodes are first grouped into clusters, each cluster forms a ring with the self healing property, then hub nodes are decided such that the number of hub nodes is minimized. The author shows that the second and third step are both NP-complete. The reconfiguration of virtual rings is also studied and a virtual ring based network control and management protocol is briefly described