Greening The Network Using Traffic Prediction and Link Rate Adaptation

Link rate adaptation is an effective means to save energy consumption of network elements by adjusting the link rate according to the carried traffic through a network-level optimization of the flow allocation process. Unfortunately, current adaptation approaches are mainly reactive, in which link speed is changed only when new traffic demand is requested. Once bandwidth has been allocated for a demand, link rate remains constant during the entire session. This approach may result in sub-optimal energy efficiency schemes and requires multiple re-optimizations as traffic flows are fluctuating during the session, hence reducing the overall network performance. In this paper, we propose a multiple-step-ahead method to predictively optimize link rates based on forecasting traffic demand. We formulate the link adaptive energy efficiency as a MIP model and propose a heuristic simulated annealing algorithm to solve it. Our experimental results show our approach provides energy saving while it significantly decreases the number of re-optimizations in the energy-aware routing.