Multi-period planning with actual physical and traffic conditions

The common practice in optical networks is to deploy them statically in a future proof approach and to operate them with only traffic/fault driven changes. Lightpaths are overprovisioned with high quality of transmission (QoT) margins to anticipate future degradations, due to interference, aging, and maintenance operations, and to account for inaccuracies in QoT estimation. Such assumptions decrease network efficiency and increase the cost. Moreover, transponders and regenerators are assigned once to demands, yielding low efficiency if traffic varies significantly. Elastic optical technology, feedback from software monitors, and software defined networking enable the dynamic operation of the network. We propose an algorithm that takes into account the actual physical layer and traffic conditions and provisions new or adapts existing lightpaths with actual (just-enough) margins, optimizing placement and transmission parameter decisions for the transponders and regenerators. Using the proposed algorithm in a multi-period scenario, we quantify the benefits that can be achieved when planning with actual margins and varying levels of traffic dynamicity.