Fragmentation Metrics in Spectrally-Spatially Flexible Optical Networks
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Spectrally-spatially flexible optical networks (SS-FONs) are proposed as a solution for future traffic requirements in optical backbone networks. As SS-FONs operate within flex-grid, the provisioning of lightpaths spanning multiple frequency slots results in spectrum fragmentation, especially in presence of dynamic traffic. Fragmentation, in turn, may lead to blocking of dynamic requests due to the lack of sufficiently-large free spectral windows. In this paper, to reach a better understanding of fragmentation in SS-FON, we extend several metrics used in (single-core) elastic optical networks to measure the fragmentation in SS-FONs. Next, we apply these metrics to a dynamic-routing algorithm with the goal of minimizing bandwidth blocking. Finally, we analyze the impact of spatial continuity constraint (SCC) on the network fragmentation. Simulations run on two representative network topologies show that the root mean square factor metric yields the best performance in terms of blocking when compared to other analyzed metrics.
KeywordsSpectrally-spatially flexible optical networks Network fragmentation Network optimization Routing Space Spectrum allocation
The work of P. Lechowicz was supported National Science Centre, Poland under Grant 2015/19/B/ST7/02490. The work of A. Włodarczyk and K. Walkowiak was supported by National Science Centre, Poland under Grant 2017/27/B/ST7/00888.
- 4.Horota, A., et al.: Routing and spectrum assignment algorithm with most fragmented path first in elastic optical networks. In: 7th IEEE Latin-American Conference on Communications (LATINCOM), pp. 1–6 (2015)Google Scholar
- 7.Liu, L., et al.: 3D elastic optical networks in temporal, spectral, and spatial domains with fragmentation-aware RSSMA algorithms. In: The European Conference on Optical Communication (ECOC), pp. 1–3 (2014)Google Scholar
- 12.Shariati, B., et al.: Realizing spectrally-spatially flexible optical networks. IEEE Photon. Soc. Newsl. 31(6), 4–9 (2017)Google Scholar
- 13.Shen, J., Chen, J., Sun, Y.: Fragmentation aware routing and spectrum assignment algorithm for elastic optical networks. In: TENCON 2015–2015 IEEE Region 10 Conference, pp. 1–4 (2015)Google Scholar
- 19.Ye, Z., Patel, A.N., Ji, P.N., Qiao, C.: Root mean square (RMS) factor for assessing spectral fragmentation in flexible grid optical networks. In: 2014 OptoElectronics and Communication Conference and Australian Conference on Optical Fibre Technology, pp. 357–358 (2014)Google Scholar