Spatial and temporal traffic variation in core Networks: Impact on energy saving and devices lifetime

We assess the impact of traffic variations on energy consumption and devices lifetime in a core network. Specifically, we first define a model to control the spatial as well as the temporal variations of traffic. We generate different sets of traffic matrices by adopting our model, which are then used as input to an energy-aware algorithm, with the aim of finding the set of Line Cards (LCs) in Sleep Mode (SM) for each traffic matrix. Given this output, we are able to compute different evaluation metrics, including: the total energy consumption, the normalized lifetime as a consequence of activation/deactivation of network devices, and the total network profitability (i.e., the monetary gain/loss for the operator). Our results show that the temporal variation of traffic affects the LCs energy consumption, but has a limited impact on their lifetime. Moreover, the spatial variation of traffic is no obstacle for energy saving. Eventually, the frequency of the power cycles, introduced by the energy-aware algorithm, is particularly important for the lifetime of LCs. Finally, we show that positive total profitability is achieved in most of the considered cases.