Fine-grained power scaling algorithms for energy efficient routers

Energy efficient router is one of the most important and promising devices in the roadmap towards green communication and networking. In recent years, automatical power scaling adapting with real-time network traffic in a router has been proved to be practical on real hardware, which is an implementation under the traffic aware philosophy. In this paper, we further explore this direction, and present four real-time power scaling algorithms for the fine-grained energy management within a router. These algorithms are all based on the traffic aware philosophy. We first classify the traffic characteristics into three categories of the core router, access router and home router and analyze the differences among them. Then, we propose two design methodologies, periodical scaling and threshold scaling, and address four algorithms in details. Finally, we use real network traffic to evaluate these algorithms and draw the conclusions. The experiments on real traffic show that more than 40% of the energy in a router can be saved by using proposed system-level power scaling methods. Based on those evaluations, we also find that three status modes with two working frequencies and a sleep in a router are enough to achieve near-optimal energy efficiency by using our algorithms, which indicates an easy and practical hardware modification.