Two Large-Scale Network Design Problems In this work we consider two large-scale network design problems arising in network routing and provisioning. The first problem combines long-term business and design decisions on large-scale telecommunication networks. The problem integrates different elements of network business planning such as capacity expansion, routing and protection and equipment m...

In the context of organizing timetables for railway companies the following railway carriage routing problem occurs. Given a timetable containing rail links with departure and destination times/stations and the composition of the trains, find a routing of railway carriages such that the required carriages are always available when a train departs. We will present a local search approach for thi...

Utilizing smart antennas in multi-hop wireless networks can boost their performance. However, most of the work done in the context of wireless adhoc and sensor networking assume ideal or over-simplistic antenna patterns that overrate the performance benefits. In this paper, we compute the optimal throughput of multi-hop wireless networks with realistic smart antenna model. Our goal is to evalua...

We consider the Network Loading Problem under a polyhedral uncertainty description of traffic demands. After giving a compact multi-commodity formulation of the problem, we prove an unexpected decomposition property obtained from projecting out the flow variables, considerably simplifying the resulting polyhedral analysis and computations by doing away with metric inequalities, an attendant fea...

It is shown that the minimum cut ratio is within a factor of O(log k) of the maximum concurrent flow for k-commodity flow instances with arbitrary capacities and demands. This improves upon the previously best-known bound of O(log k) and is existentially tight, up to a constant factor. An algorithm for finding a cut with ratio within a factor of O(log k) of the maximum concurrent flow, and thus...

Max-min is an established fairness criteria for allocating bandwidth for flows. In this work we look at the combined problem of routing and bandwidth allocation such that the flow allocation for each connection will be maximized and fairness will be maintained. We use the weighted extension of the max-min criteria to allocate bandwidth proportionaly to the flows’ demand. Our contribution is an ...

We describe a two-stage robust optimization approach for solving network flow and design problems with uncertain demand. In two-stage network optimization one defers a subset of the flow decisions until after the realization of the uncertain demand. Availability of such a recourse action allows one to come up with less conservative solutions compared to single-stage optimization. However, this ...