Abstract
Flexgrid optical networks are attracting huge interest due to their higher spectrum efficiency and flexibility in comparison with traditional wavelength switched optical networks based on the wavelength division multiplexing technology. To properly analyze, design, plan, and operate flexible and elastic networks, efficient methods are required for the routing and spectrum allocation (RSA) problem. Specifically, the allocated spectral resources must be, in absence of spectrum converters, the same along the links in the route (the continuity constraint) and contiguous in the spectrum (the contiguity constraint). In light of the fact that the contiguity constraint adds huge complexity to the RSA problem, we introduce the concept of channels for the representation of contiguous spectral resources. In this paper, we show that the use of a pre-computed set of channels allows considerably reducing the problem complexity. In our study, we address an off-line RSA problem in which enough spectrum needs to be allocated for each demand of a given traffic matrix. To this end, we present novel integer lineal programming (ILP) formulations of RSA that are based on the assignment of channels. The evaluation results reveal that the proposed approach allows solving the RSA problem much more efficiently than previously proposed ILP-based methods and it can be applied even for realistic problem instances, contrary to previous ILP formulations.
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References
Jinno M., Takara H., Kozicki B., Tsukishima Y., Sone Y., Matsuoka S.: Spectrum-efficient and scalable elastic optical path network: architecture, benefits, and enabling technologies. IEEE Commun. Mag. 47, 66–73 (2009)
Jinno M., Kozicki B., Takara H., Watanabe A., Sone Y., Tanaka T., Hirano A.: Distance-adaptive spectrum resource allocation in spectrum-sliced elastic optical path network. IEEE Commun. Mag. 48, 138–145 (2010)
ITU-T G.694.1: Spectral grids for WDM applications: DWDM frequency grid. May 2002
Christodoulopoulos K., Tomkos I., Varvarigos E.: Elastic bandwidth allocation in flexible OFDM based optical networks. IEEE J. Lightwave Technol. 29, 1354–1366 (2011)
Wang, Y., Cao, X., Pan, Y.: A study of the routing and spectrum allocation in spectrum-sliced elastic optical path networks. In: Proceedings of IEEE INFOCOM 2011
Klinkowski M., Walkowiak K.: Routing and spectrum assignment in spectrum sliced elastic optical path network. IEEE Commun. Lett. 15, 884–886 (2011)
Pióro M., Medhi D.: Routing, Flow, and Capacity Design in Communication and Computer Networks. Morgan Kaufmann, California (2004)
Pavan C., Morais R., Ferreira J., Pinto A.: Generating realistic optical transport network topologies. IEEE/OSA J. Opt. Commun. Netw. 2, 80–90 (2010)
SNDlib http://sndlib.zib.de/
CPLEX http://www-01.ibm.com/software/integration/optimization/cplex-optimizer/
Sone Y., Watanabe A., Imajuku W., Tsukishima Y., Kozicki B., Takara H., Jinno M.: Bandwidth squeezed restoration in spectrum-sliced elastic optical path networks (SLICE). IEEE/OSA J. Opt. Commun. Netw. 3, 223–233 (2011)
Velasco, L., Klinkowski, M., Ruiz, M., López, V., Junyent, G.: Elastic Spectrum Allocation for Variable Traffic in Flexible-Grid Optical Networks. In: IEEE/OSA Optical Fiber Communication Conference (OFC), March 2012
Pedrola, O., Velasco, L., Castro, A., Fernández-Palacios, J., Careglio, D., Junyent, G.: CAPEX study for grid dependent multi-layer IP/MPLS-over-EON using relative BV-WSS costs. In: IEEE/OSA Optical Fiber Communication Conference (OFC), March 2012
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Velasco, L., Klinkowski, M., Ruiz, M. et al. Modeling the routing and spectrum allocation problem for flexgrid optical networks. Photon Netw Commun 24, 177–186 (2012). https://doi.org/10.1007/s11107-012-0378-7
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DOI: https://doi.org/10.1007/s11107-012-0378-7