Browsing by Subject "Network loading problem"

Now showing 1 - 2 of 2

Open Access
Placement of express links in a DWDM optical network
(2005) Şöhret, Oğuz
With the introduction of DWDM technology in telecommunication network systems, important advancements have been achieved in the problem of routing the increasing signal traffic between demand-supply nodes. The choice of the links to open, the number of links and routing of current traffic on these links in such an optical network system are important in terms of decreasing the complexity of the network and cost savings. The study in this thesis firstly introduces the use of express links, which enables those objectives, and then determines the appropriate network structure and routing. The study introduces two mathematical models as well as a lagrangian based heuristic for the solution of the problem.
Open Access
The robust network loading problem under hose demand uncertainty: formulation, polyhedral analysis, and computations
(Institute for Operations Research and the Management Sciences (I N F O R M S), 2011) Altın, A.; Yaman, H.; Pınar, M. Ç.
We consider the network loading problem (NLP) under a polyhedral uncertainty description of traffic demands. After giving a compact multicommodity flow formulation of the problem, we state a decomposition property obtained from projecting out the flow variables. This property considerably simplifies the resulting polyhedral analysis and computations by doing away with metric inequalities. Then we focus on a specific choice of the uncertainty description, called the "hose model," which specifies aggregate traffic upper bounds for selected endpoints of the network. We study the polyhedral aspects of the NLP under hose demand uncertainty and use the results as the basis of an efficient branch-and-cut algorithm. The results of extensive computational experiments on well-known network design instances are reported.