Author : Sridhar Iyer 1
Date of Publication :14th April 2017
Abstract: In recent years, with introduction of elasticity (flexibility) in optical networks, bandwidth utilization can be adjusted as per the requests and also, longer transmission reach and higher spectral-efficiency can be provisioned. In view of optical transmission, elastic optical networks (EONs) resort to the use of elastic frequency grids and advanced modulation formats which necessitate solutions to the novel routing and spectrum allocation (RSA) approaches. In the current work, we compare various dynamic dual step RSA approaches applicable to the EONs. Specifically, we analyze and compare various (i) k-shortest path based approaches for the routing step, and (ii) approaches for the spectrum allocation step. Our simulation results demonstrate (i) effectiveness of the RSA approaches in regard to the considered network topologies which utilize the connections’ demanded bandwidth, and (ii) improvement in the shortest path first approach’s performance with an increase in candidate route’s numbers for a network with higher numbers of nodes and links.
 O. Gerstel, M. Jinno, A. Lord, and S.J. Yoo, “Elastic Optical Networking: A New Dawn for the Optical Layer”, IEEE Commun. Mag, vol. 50, pp. S12-S20, 2012.
 A. Napoli et al., “Next Generation Elastic Optical Networks: The Vision of the European Research Project IDEALIST. IEEE Commun. Mag, vol. 53, pp. 152-162, 2015.
 M. Jinno, B. Kozicki, H. Takara, A. Watanabe, Y. Sone, T. Tanaka, and A. Hirano, “Distance-adaptive spectrum resource allocation in spectrum sliced elastic optical path network”, IEEE Commun. Mag, vol. 48, pp. 138–145, 2010.
 G. Zhang, M. De Leenheer, A. Morea, and B. Mukherjee, “A Survey on OFDM-Based Elastic Core Optical Networking”, IEEE Commun. Surv. & Tut., vol. 15, pp. 65–87, 2013.
 M. Jinno, H. Takara, B. Kozicki, Y. Tsukishima, Y. Sone, and S. Matsuoka, “Spectrum-efficient and scalable elastic optical path network: architecture, benefits, and enabling technologies”, IEEE Commun. Mag, vol. 47, pp. 66–73, 2009.
 ITU-T. Spectral grids for WDM applications: DWDM frequency grid. ITU-T Recommendation G.694.1, 2012.
 K. Christodoulopoulos, I. Tomkos, and E. Varvarigos, “Elastic Bandwidth Allocation in Flexible OFDM-Based Optical Networks”, IEEE Journal of Lightwave Technology, vol. 29, pp. 1354–1366, 2011.
 L. Velasco, M. Klinkowski, M. Ruiz, and J. Comellas, “Modeling the routing and spectrum allocation problem for flexgrid optical networks”, Photonic Network Communications, Springer, vol. 24, pp. 177–186, 2012.
 Z. Zhu, W. Lu, L. Zhang, and N. Ansari, “Dynamic Service Provisioning in Elastic Optical Networks With Hybrid Single-/Multi-Path Routing”, IEEE Journal of Lightwave Technology, pp. 31, pp. 15–22, 2013.
 I. Olszewski, “Dynamic RSA problem for timevarying traffic in spectrum sliced elastic optical path network”, International Journal of Electronics and Telecommunications, vol. 61, pp. 179–184, 2015.
 S. Talebi, F. Alam, I. Katib, M. Khamis, R. Salama, and G.N. Rouskas, “Spectrum management techniques for elastic optical networks: A survey”, Optical Switching and Networking, Elsevier, vol. 13, pp. 34–48, 2014.
 B.C. Chatterjee, N. Sarma, and E. Oki, “Routing and Spectrum Allocation in Elastic Optical Networks: A Tutorial”, IEEE Commun. Surv. & Tut., vol. 17, pp. 1776– 1800, 2015.
 L. Zhang, W. Lu, X. Zhou, and Z. Zhu, “Dynamic RMSA in spectrum sliced elastic optical networks for highthroughput service provisioning”, in Proc. IEEE International Conference on Computing, Networking and Communications (ICNC), pp. 380–384, 2013.
 A. Rosa, C. Cavdar, S. Carvalho, J. Costa, and L. Wosinska, “Spectrum allocation policy modeling for elastic optical networks”, in Proc. IEEE International Conference on High Capacity Optical Networks and Enabling Technologies (HONET), pp. 242–246, 2012.
 B.C. Chatterjee, and E. Oki, “Performance evaluation of spectrum allocation policies for elastic optical networks”, in Proc. IEEE International Conference on Transparent Optical Networks (ICTON), pp. 1–4, 2015.
 IDEALIST Project. Elastic Optical Network Architecture: Reference scenario, cost and planning. Deliverable D1.1, 2014, Available:http://cordis.europa.eu/docs/projects/cnect/9/317 999/080/deliv erables/001D11ElasticOpticalNetworkArchitecture.doc