Browsing by Author "Zotkiewicz, Mateusz"

Now showing items 1-8 of 8

    • A column generation approach for large-scale RSA-based network planning 

      Ruiz Ramírez, Marc; Zotkiewicz, Mateusz; Velasco Esteban, Luis Domingo; Comellas Colomé, Jaume (Institute of Electrical and Electronics Engineers (IEEE), 2013)
      Conference report
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      In flexgrid-based optical networks, the problem of finding optimal route and spectrum allocation (RSA) for the demands in a traffic matrix becomes harder to solve than similar problems in fixed DWDM networks, mainly due ...

    • After failure repair optimization in dynamic flexgrid optical networks 

      Ruiz Ramírez, Marc; Zotkiewicz, Mateusz; Castro Casales, Alberto; Klinkowski, Miroslaw; Velasco Esteban, Luis Domingo; Pioro, Michal (The Optical Society (OSA), 2014)
      Conference report
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      We introduce the problem of reoptimizing the network after a link failure has been repaired as an effective way for reducing capacity usage and improving network performance. Numerical results show gains higher than 42%.

    • Column generation algorithm for RSA problems in flexgrid optical networks 

      Ruiz Ramírez, Marc; Pioro, Michal; Zotkiewicz, Mateusz; Klinkowski, Miroslaw; Velasco Esteban, Luis Domingo (2013-10)
      Article
      Restricted access - publisher's policy
      Finding optimal routes and spectrum allocation in flexgrid optical networks, known as the RSA problem, is an important design problem in transport communication networks. The problem is TeX -hard, and its intractability ...

    • Optimization models for flexgrid elastic optical networks 

      Zotkiewicz, Mateusz; Pioro, Michal; Ruiz Ramírez, Marc; Klinkowski, Miroslaw; Velasco Esteban, Luis Domingo (Institute of Electrical and Electronics Engineers (IEEE), 2013)
      Conference report
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      In the paper we present integer programming (IP) optimization models for flexgrid elastic optical networks (EON). We consider several different basic assumptions regarding flexibility of EON that lead to a variety of IP ...

    • Reoptimization of dynamic flexgrid optical networks after link failure repairs 

      Zotkiewicz, Mateusz; Ruiz Ramírez, Marc; Klinkowski, Miroslaw; Pioro, Michal; Velasco Esteban, Luis Domingo (Institute of Electrical and Electronics Engineers (IEEE), 2015-01-01)
      Article
      Open Access
      In dynamic flexgrid optical networks, the usage of capacity may not be optimal due to the permanent process of setting up and tearing down connections, which, if not controlled, leads to spectrum fragmentation and, as a ...

    • Solving large instances of the RSA problem in flexgrid elastic optical networks 

      Walkowiak, Krzysztof; Zotkiewicz, Mateusz; Klinkowski, Miroslaw; Pioro, Michal; Ruiz Ramírez, Marc; Velasco Esteban, Luis Domingo (Institute of Electrical and Electronics Engineers (IEEE), 2016-05-01)
      Article
      Open Access
      We present an optimization procedure that mixes advanced large-scale optimization methods and heuristics to solve large instances (with over 1.7 million integer variables) of the routing and spectrum allocation (RSA) ...

    • Spectrum allocation problem in elastic optical networks - a branch-and-price approach 

      Pioro, Michal; Klinkowski, Miroslaw; Zotkiewicz, Mateusz; Walkowiak, Krzysztof; Ruiz Ramírez, Marc; Velasco Esteban, Luis Domingo (Institute of Electrical and Electronics Engineers (IEEE), 2015)
      Conference report
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      In the paper we present a branch and price approach to routing and spectrum allocation – a basic optimization problem in elastic optical networks. We formulate the problem as a mixed-integer program for which ...

    • Valid inequalities for the routing and spectrum allocation problem in elastic optical networks 

      Klinkowski, Miroslaw; Pioro, Michal; Zotkiewicz, Mateusz; Ruiz Ramírez, Marc; Velasco Esteban, Luis Domingo (Institute of Electrical and Electronics Engineers (IEEE), 2014)
      Conference report
      Restricted access - publisher's policy
      We deal with a natural integer-linear programming formulation of the routing and spectrum allocation (RSA) problem in elastic optical networks. We focus on strengthening the formulation with valid inequalities (cuts). For ...