View article

We study a planning problem arising in SDH/WDM multilayer telecommunication network design. The goal is to find a minimum cost installation of link and node hardware of both network layers such that traffic demands can be realized via grooming and a survivable routing. We present a mixed-integer programming formulation for a predefined set of admissible logical links that takes many practical side constraints into account, including node hardware, several bit rates, and survivability against single physical node or link failures. This model is solved using a branch-and-cut approach with problem-specific preprocessing, MIPbased heuristics, and cutting planes based on either of the two layers. On several realistic two-layer planning scenarios, we show that these ingredients can be very useful to reduce the optimality gaps in the multilayer context.