“Follow the Sun, Follow the Wind” Lightpath Virtual Topology Reconfiguration in IP Over WDM Network

Green House Gas (GHG) emissions mainly come from the consumption of non-renewable energy. To reduce GHG emissions of IP over WDM networks, we propose to maximize renewable energy usage at each network node location so as to reduce the consumption of non-renewable energy. A “Follow the Sun, Follow the Wind” strategy is proposed for the IP over WDM network to periodically reconfigure the lightpath virtual topology to enable more lightpaths to start or end at nodes where maximum renewable energy is available. We develop a mixed integer linear programming model to design new lightpath virtual topologies. Since the computational complexity of the optimization model is excessive, we also propose a simple but efficient heuristic algorithm to tackle this. Our results indicate that a network operated in this way can significantly reduce non-renewable energy consumption as illustrated in the example network scenarios considered.