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  <doc>
    <id>824</id>
    <completedYear/>
    <publishedYear/>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>reportzib</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2004-12-14</completedDate>
    <publishedDate>2004-12-14</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">An Integer Programming Model for Multi-Layer Network Design</title>
    <abstract language="eng">We present an integer linear programming model for the design of multi-layer telecommunication networks. The formulation integrates hardware, capacity, routing, and grooming decisions in \emph{any} n umber of network layers. Practical hardware restrictions and cost can accurately be taken into account for technologies based on connection-oriented routing protocols.</abstract>
    <identifier type="serial">04-49</identifier>
    <identifier type="opus3-id">825</identifier>
    <identifier type="urn">urn:nbn:de:0297-zib-8248</identifier>
    <author>Sebastian Orlowski</author>
    <author>Roland Wessäly</author>
    <series>
      <title>ZIB-Report</title>
      <number>04-49</number>
    </series>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>multi-layer networks</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>integer programming</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>network design</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>routing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>grooming</value>
    </subject>
    <collection role="ddc" number="000">Informatik, Informationswissenschaft, allgemeine Werke</collection>
    <collection role="msc" number="68M10">Network design and communication [See also 68R10, 90B18]</collection>
    <collection role="msc" number="90C11">Mixed integer programming</collection>
    <collection role="msc" number="90C57">Polyhedral combinatorics, branch-and-bound, branch-and-cut</collection>
    <collection role="institutes" number="">ZIB Allgemein</collection>
    <file>https://opus4.kobv.de/opus4-zib/files/824/ZR-04-49.ps</file>
    <file>https://opus4.kobv.de/opus4-zib/files/824/ZR-04-49.pdf</file>
  </doc>
  <doc>
    <id>731</id>
    <completedYear/>
    <publishedYear/>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>reportzib</type>
    <publisherName/>
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    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2003-04-16</completedDate>
    <publishedDate>2003-04-16</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Comparing Restoration Concepts using Optimal Network Configurations with Integrated Hardware and Routing
Decisions</title>
    <abstract language="eng">We investigate the impact of link and path restoration on the cost of telecommunication networks. The surprising result is the following: the cost of an optimal network configuration is almost independent of the restoration concept if (i) the installation of network elements (ADMs, DXCs, or routers) and interface cards, (ii) link capacities, and (iii) working and restoration routings are simultaneously optimized. We present a mixed-integer programming model which integrates all these decisions. Using a branch-and-cut algorithm (with column generation to deal with all potential routing paths), we solve structurally different real-world problem instances and show that the cost of optimal solutions is almost independent of the used restoration concept. In addition, we optimize spare capacities for given shortest working paths which are predetermined with respect to different link metrics. In comparison to simultaneous optimization of working and restoration routings, it turns out that this approach does not allow to obtain predictably good results.</abstract>
    <identifier type="serial">03-09</identifier>
    <identifier type="opus3-id">732</identifier>
    <identifier type="urn">urn:nbn:de:0297-zib-7316</identifier>
    <enrichment key="SourceTitle">Appeared in: Journal of Network and Systems Management 13 (2005) 99-118</enrichment>
    <author>Sebastian Orlowski</author>
    <author>Roland Wessäly</author>
    <series>
      <title>ZIB-Report</title>
      <number>03-09</number>
    </series>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>survivable network design</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>link and path restoration</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>hardware configuration</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>branch-and-cut algorithm</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>routing</value>
    </subject>
    <collection role="ddc" number="000">Informatik, Informationswissenschaft, allgemeine Werke</collection>
    <collection role="msc" number="68M10">Network design and communication [See also 68R10, 90B18]</collection>
    <collection role="msc" number="90C11">Mixed integer programming</collection>
    <collection role="msc" number="90C57">Polyhedral combinatorics, branch-and-bound, branch-and-cut</collection>
    <collection role="institutes" number="">ZIB Allgemein</collection>
    <file>https://opus4.kobv.de/opus4-zib/files/731/ZR-03-09.ps</file>
    <file>https://opus4.kobv.de/opus4-zib/files/731/ZR-03-09.pdf</file>
  </doc>
  <doc>
    <id>798</id>
    <completedYear/>
    <publishedYear/>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>reportzib</type>
    <publisherName/>
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    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2004-06-08</completedDate>
    <publishedDate>2004-06-08</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">The Effect of Hop Limits on Optimal Cost in Survivable Network Design</title>
    <abstract language="eng">We investigate the impact of hop-limited routing paths on the total cost of a telecommunication network. For different survivability settings (dedicated protection, link and path restoration), the optimal network cost without restrictions on the admissible path set is compared to the results obtained with two strategies to impose hop limits on routing paths. In a thorough computational study on optimal solutions for nine real-world based problem instances, we show that hop limits should be avoided if the technology allows it and network cost is a major planning issue. In this case, column generation should be employed to deal with all routing paths. If hop-limits are required, these should be defined for each demand individually and as large as possible.</abstract>
    <identifier type="serial">04-23</identifier>
    <identifier type="opus3-id">799</identifier>
    <identifier type="urn">urn:nbn:de:0297-zib-7980</identifier>
    <enrichment key="SourceTitle">Appeared in: Telecommunications Planning: Innovations in Pricing, Network Design and Management. Eds. S. Raghavan and G. Anandalingam. OR/CS Interfaces vol. 33, chapter 8, pp. 151-166. Springer, January 2006</enrichment>
    <author>Sebastian Orlowski</author>
    <author>Roland Wessäly</author>
    <series>
      <title>ZIB-Report</title>
      <number>04-23</number>
    </series>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>survivable network design</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>hop limits</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>routing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>restoration</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>branch-and-cut algorithm</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>mixed-integer programming</value>
    </subject>
    <collection role="ddc" number="000">Informatik, Informationswissenschaft, allgemeine Werke</collection>
    <collection role="msc" number="68M10">Network design and communication [See also 68R10, 90B18]</collection>
    <collection role="msc" number="90C11">Mixed integer programming</collection>
    <collection role="msc" number="90C57">Polyhedral combinatorics, branch-and-bound, branch-and-cut</collection>
    <collection role="institutes" number="">ZIB Allgemein</collection>
    <file>https://opus4.kobv.de/opus4-zib/files/798/ZR-04-23.ps</file>
    <file>https://opus4.kobv.de/opus4-zib/files/798/ZR-04-23.pdf</file>
  </doc>
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