Traffic Grooming for WDM Rings with Dynamic Traffic

We study the problem of traffic grooming in wavelength-division-multiplexing (WDM) rings with dynamic traffic. We consider both unidirectional and bi-directional rings. In our dynamic traffic model, traffic is represented by a set of different traffic requirements that the network needs to satisfy, but at different times. Our objective is to minimize the required number of electronic add/drop multiplexers (ADMs). We first formulate the problem as an integer linear programming (ILP) problem. However, in general, it is computational infeasible to solve the resulting ILP problem. Therefore, we propose a heuristic method in combination with the ILP formulation, in which we first use the ILP formulation to find a traffic grooming solution that minimizes the number of wavelengths, based on which we then construct a solution that uses as few ADMs as possible. Numerical results are provided to validate our method.