Performance analysis of topology-oriented solutions on energy efficient networks

Telecommunication networks have been designed and deployed with over-provisioning and redundancy of resources to cope with traffic load during peak hours and quickly recover from failure. However, most of these resources are underutilized and in most of the time idle but consuming full energy. With the growing concern of energy waste and greenhouse gases (GHG), the network design principles tend to shift to allocate resources on-demand and be energy-efficient. In this paper, we analyze and evaluate the performance of two energy-saving techniques, namely Energy Saving TOPology control (ESTOP) for coordinated sleeping, and Energy Efficient Ethernet (EEE) for uncoordinated sleeping. Furthermore, we evaluate the potential of combining ESTOP and EEE considering that the reduced topologies obtained running ESTOP can substantially increase link utilization and the length of some paths and therefore degrade the performance of EEE. The evaluation was conducted in OMNet++ with realistic and synthetic networks under different traffic conditions. The results show that the energy conservation of the combination is significant when a lower value of the connectivity threshold is used during off-peak hours and a higher value is used during peak hours. ESTOP depends on the density of the topology and can save about 50% of energy.