Datarate Adaptation for Night-Time Energy Savings in Core Networks

We examine how datarate-adaptive transceivers can be used to follow the pronounced variations in requested bandwidth in core networks and therefore allow significant energy savings compared to static networks operating at all time for peak traffic. We investigate two schemes for datarate adaptation in optical transceivers, namely modulation-format adaptation and symbol-rate adaptation, and show how they yield comparable energy savings but through very different mechanisms. We quantify these energy savings with respect to static networks for the case of a European backbone network and find potential for up to 30% when the two schemes are combined.