Key performance indicators for elastic optical transponders and ROADMs:the role of flexibility

Flexible optical networks will provide the required service diversity to manage unpredictable traffic patterns and growth. However, a key challenge is to quantify flexibility in order to indicate the associated performance of individual components and subsystems required to support networks and correlate it with other figures of merit. Measurable key performance indicators will aid the process towards the design and deployment of cost effective and efficient optical networks. Moreover, the design and placement of network elements within a network influences the resultant network-wide flexibility and performance. In this paper, we highlight critical design parameters for key optical components, optical transmission and switching subsystems using flexibility as an additional figure of merit. We derive models to measure the flexibility of key optical components, optical transmission and switching subsystems based on entropy maximization. Using these models, we evaluate flexibility and design trade-offs of the presented enabling technologies with other key performance indicators such as spectral efficiency, lightpath reach, total capacity, normalized cost, connectivity and others. This study provides an advanced and more informed set of design rules that quantify and visualize the different degrees of flexibility of enabling technologies and associated performance based on required specification and/or functionality