Green Communications: Principles, Concepts and Practice

Chapter 13Green Routing/Switching and Transport

Luca Chiaraviglio, Antonio Cianfrani, Angelo Coiro, Marco Listanti and Marco Polverini

DIET Department, University of Rome “Sapienza”, Rome, Italy

13.1 Energy-Saving Strategies for Backbone Networks

In the last decade, the energy consumption of Internet has been hugely fuelled by an increase of the number of connected devices causing an explosion of traffic volume. Consequently, energy-restraint strategies have become a crucial element to prevent the Internet from being throttled by an energy bottleneck. The challenge is to make the increase of the Internet operational efficiency faster than the rate of traffic growth.

Several studies [3] tried to foresee the future Internet energy consumption over the next 15 years (2010–2025). These studies divide the network in two segments: the access segment, realized with heterogeneous technologies, and a backbone segment, composed of high-capacity IP routers and transmission devices. It is foreseen that, at the end of the considered time interval, the overall carried traffic will achieve a total increment of 2–3 orders of magnitude, while the energy per bit consumed by the networking equipment will decrease in the range of 15–20% per year. Basic results of these studies show that, though at present (2013) the access network is about two orders of magnitude higher power than the backbone segment, in the near future, due to the foreseen traffic increase, the overall energy consumption of ...