Technical challenges and deployment perspectives of SDN based elastic optical networks

There is a widespread acceptance that the flex-grid technology is the future of the transport network due to its astounding characteristics: flexible bandwidth allocation and reach tailoring through adaptive line rate, modulation formats, and spectral efficiency. However the number of variables to be optimized and the challenges to be overcome are enormous: routing, code and spectrum assignment; multi-domain and multi-technology orchestration; bandwidth variable transponders; modulation formats; monitoring aspects, just to name a few. In this paper, we exploit the software defined elastic optical networks (SD-EONs) aiming at identifying its state of art and the future challenges in terms of efficient dynamic resources assignment. In addition, we present some up-to-date information concerning the perspectives that operators carry out real deployments of this technology in the core network where currently predominate GMPLS solutions.