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@PHDTHESIS{Claen:465292,
      author       = {Claßen, Grit},
      othercontributors = {Koster, Arie M. C. A. and Schmeink, Anke},
      title        = {{O}ptimisation under {D}ata {U}ncertainty in {W}ireless
                      {C}ommunication {N}etworks},
      school       = {RWTH Aachen University},
      type         = {Dissertation},
      address      = {Aachen},
      publisher    = {Publikationsserver der RWTH Aachen University},
      reportid     = {RWTH-2015-01650},
      pages        = {VIII, 258 S. : Ill., graph. Darst.},
      year         = {2015},
      note         = {Aachen, Techn. Hochsch., Diss., 2015},
      abstract     = {In this thesis, we study robustness concepts of
                      mathematical optimisation and apply these to wireless
                      network problems which are subject to data uncertainty.
                      Uncertainties occur quite frequently in radio networks as,
                      for instance, the quality of the transmission signal varies
                      or user demands fluctuate. Robust and stochastic
                      optimisation are two methodologies to tackle such deviations
                      already in the planning phase of the network. While
                      stochastic optimisation is a suitable technique in case that
                      the uncertain data obeys a previously known probability
                      distribution, robust optimisation is able to handle
                      uncertain data which can be modelled by a so-called
                      uncertainty set, which may, e.g., be constructed from
                      historical information. One reason for the popularity of
                      robust optimisation is that the theoretical complexity of
                      the original problem is not increased by the incorporation
                      of uncertainty. We investigate one specific area of
                      stochastic optimisation, chance constraints, which are
                      related to robust optimisation, and three robustness
                      concepts. These concepts comprise Γ-robustness, the more
                      general multi-band robustness, and the two-stage approach
                      recoverable robustness.For reliable fixed broadband wireless
                      networks, we develop miscellaneous (linear) formulations
                      based on chance constraints and propose performance
                      improvements such as valid inequalities and a primal
                      heuristic. Furthermore, we apply all three robustness
                      concepts to the planning problem of mobile wireless networks
                      and propose integer linear programming formulations for each
                      robust problem. For the Γ-robust wireless network planning
                      problem (WNPP), we additionally develop valid inequalities
                      and an alternative formulation via a complete
                      branch-and-price framework. Since the knapsack problem (KP),
                      which is one of the most fundamental combinatorial problems,
                      is a subproblem of the WNPP, we study the multi-band robust
                      KP theoretically and derive new complexity results via a
                      dynamic programming algorithm. To apply this algorithm to a
                      variant of the multi-band robust WNPP, we adopt Lagrangian
                      relaxation. Additionally, we incorporate recoverable
                      robustness to the WNPP to model the option of switching base
                      stations off during low traffic times. Furthermore, to
                      obtain a full description of mobile wireless networks, we
                      develop novel approaches and discuss modifications of
                      existing formulations to model interference in the WNPP. All
                      theoretical investigations are supported by several
                      extensive computational studies performed on realistic test
                      instances. Moreover, we compare the two different
                      formulations of the Γ-robust WNPP and Γ-robust to
                      multi-band robust solutions via a numerical evaluation.
                      Finally, we discuss the interpretation of computational
                      studies critically based on the so-called performance
                      variability which is intrinsic to mixed integer linear
                      programs. We conclude by final remarks on the investigated
                      robustness concepts and present future research topics.},
      cin          = {113320 / 617120 / 110000},
      ddc          = {510},
      cid          = {$I:(DE-82)113320_20140620$ / $I:(DE-82)617120_20140620$ /
                      $I:(DE-82)110000_20140620$},
      typ          = {PUB:(DE-HGF)11},
      urn          = {urn:nbn:de:hbz:82-rwth-2015-016505},
      url          = {https://publications.rwth-aachen.de/record/465292},
}