Routing, fiber, band, and spectrum assignment (RFBSA) for multi-granular elastic optical networks

The dramatic growth of Internet traffic brings challenges for optical network designers. There have been a number of advances recently in increasing fiber bandwidth and spectrum utilization efficiency through elastic optical networking (EON). In EON, a flexible and more fine-grained grid than conventional approaches is employed, and this allows allocated fiber bandwidth to better match traffic demands. Despite these advances, imminent fiber capacity exhaustion means that multiple fibers per link will be inevitable. In an effort to reduce the complexity of optical crossconnects, a flexible wavebanding crossconnect has been proposed recently. Elastic networking and flexible wavebanding introduce a new problem, namely, the routing, fiber, waveband, and spectrum assignment (RFBSA) problem. In this work, we propose new cost functions that are pluggable into an auxiliary layered-graph framework to solve the RFBSA problem with different objectives. We focus on minimizing the maximum spectrum usage for a set of traffic demands, and show that our approach outperforms traditional approaches.