Browsing by Subject "Network Topology Design"

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    Algorithms for the integer multicommodity network design problem
    (2004) Kılınç, Mustafa Rasim
    In this thesis, we study the problem of logical network design in telecommunication networks. Given a set of nodes and a set of commodities, we aim to locate lightpaths(links) between nodes and route the commodities over these lightpaths. The cost to be minimized is the number of lightpaths used. The problem has capacity, degree and delay constraints. An important characteristic of our problem is that the commodities can not be split, therefore they must be routed on a single path. We present two integer programming formulations of the problem and consider four sets of valid inequalities. Additionally, a relaxation of the problem is presented to obtain a lower bound to the problem. Finally, we propose two algorithms of generating good feasible solutions to the problem. Our results prove to be close to the lower bounds.
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    Topology design in communication networks
    (2003) Kepek, İlktuğ Çağatay
    In this thesis, we study the topology design problem in communication networks. It is the problem of a Virtual Private Network(VPN) provider. Given a set of customer nodes and a set of commodities, we aim to locate links between customer nodes and route the commodities over these links. The cost to be minimized is the sum of location and routing costs. The problem has capacity, degree and delay constraints. An important characteristic of the problem is that the commodities cannot be split, therefore they must be routed over single paths. We present an integer programming formulation of the problem and introduce two sets of valid inequalities. The problem has two parts: locating links and routing commodities. We first analyze the commodity routing problem and propose an efficient heurisric for it. Finally we propose a heuristic method of generating good feasible solutions to our problem. The final heuristic is a Tabu Search which uses the first heuristic proposed for routing problem as a subroutine. Our results prove to be closer to the lower bounds we generate than previously proposed heuristics.