Grit Claßen

• Dipl. Comp.-Math.
• Research Assistant at RWTH Aachen University

In this paper, we consider the multi-band robust knapsack problem which generalizes the F-robust knapsack problem by subdividing the single deviation band into several smaller bands. We state a compact ILP formulation and develop two dynamic programming algorithms based on the presented model where the first has a complexity linear in the number of...

In this paper, we consider the network loading problem under demand uncertainties with static routing, i.e., a single routing scheme based on the fraction of the demands has to be determined. We generalize the class of metric inequalities to the γ-robust setting and show that they yield a formulation in the capacity space. We describe a polynomial...

In this paper, we extend our former investigation on conceiving reliable fixed point-to-point wireless networks under outage probability constraints. We consider the problem of determining the minimum cost bandwidth assignment of a network, while guaranteeing a reliability level of the solution. If the optimal bandwidth assignment and routing of tr...

The wireless network planning problem consists of base station placement and traffic node assignment to base stations. To incorporate traffic demand uncertainties, we follow the $\varGamma $ Γ -robustness approach by Bertsimas and Sim. In this paper, we develop a branch-and-price algorithm, with the aim to enhance the solution process and impro...

In this paper, we present an optimisation model for the energy-efficient planning of future wireless networks. By applying robust optimisation, we extend this model to a robust formulation which considers demand uncertainties. The computability of the resulting model is moderate. Hence, we apply three different cutting plane approaches for an impro...

Current methods dealing with the energy efficient wireless network planning problem require a static model. However, bit rate requirements vary and rise over time, users move around and path gain fluctuates. In this paper, robust optimization is applied to deal with demand uncertainty. We present a robust optimization model for the energy-efficient...

In this paper, we investigate on conceiving reliable fixed broadband wireless networks under outage probability constraints. We introduce a joint model of data routing and bandwidth assignment that minimizes the total renewal fees of licenses. This problem differs from classical capacity planning since the capacity of microwave links is prone to va...

In this paper, we propose a chance-constrained mathematical program for fixed broadband wireless networks under unreliable channel conditions. The model is reformulated as an integer linear program and valid inequalities are derived for the corresponding polytope. Computational results show that by an exact separation approach the optimality gap is...