Formulation of multi-hop dynamic traffic grooming in WDM optical networks

Traffic grooming in wavelength division multiplexing (WDM) optical networks studies consolidation of sub-wavelength client traffic onto lightpaths. The principal problem in traffic grooming is to construct a logical topology, and to route client traffic over the constructed logical topology. This paper studies dynamic traffic grooming where client traffic randomly arrives/departs. For dynamic traffic grooming, the logical topology may be dynamically configured, or designed a priori given the stationary traffic demands between client nodes (and reconfigured in relatively large time scale, e.g., on the order of hours, to adapt to changing traffic demands). This paper studies the latter case and formulates it into an integer linear programming (ILP) problem. The formulation minimizes the used network resource, constrained by the requirement of client traffic blocking probability, the maximum by-pass traffic amount allowed at each client node, and the number of ports at each client node. It also integrates wavelength assignment and addresses the most general sparse limited wavelength conversion.