Energy Consumption in Optical IP Networks

TLDR

Global energy concerns have made the Internet’s power consumption an increasingly important issue. This study introduces a network‑based model to estimate the current and future power consumption of the Internet. The model incorporates core, metro, edge, access, and video distribution layers, accounts for switching and transmission equipment, and includes multiple access technologies such as ADSL2+, PON, FTTH, and point‑to‑point optics, allowing predictions of future consumption with anticipated equipment efficiency gains. The model estimates that today’s Internet consumes about 0.4 % of electricity in broadband‑enabled countries, could rise to roughly 1 % as access rates grow, and that energy per bit drops from ~75 µJ at low rates to 2–4 µJ at 100 Mb/s.

Abstract

As community concerns about global energy consumption grow, the power consumption of the Internet is becoming an issue of increasing importance. In this paper, we present a network-based model of power consumption in optical IP networks and use this model to estimate the energy consumption of the Internet. The model includes the core, metro and edge, access and video distribution networks, and takes into account energy consumption in switching and transmission equipment. We include a number of access technologies, including digital subscriber line with ADSL2+, fiber to the home using passive optical networks, fiber to the node combined with very high-speed digital subscriber line and point-to-point optical systems. In addition to estimating the power consumption of today's Internet, we make predictions of power consumption in a future higher capacity Internet using estimates of improvements in efficiency in coming generations of network equipment. We estimate that the Internet currently consumes about 0.4% of electricity consumption in broadband-enabled countries. While the energy efficiency of network equipment will improve, and savings can be made by employing optical bypass and multicast, the power consumption of the Internet could approach 1% of electricity consumption as access rates increase. The energy consumption per bit of data on the Internet is around 75\bm muJ at low access rates and decreases to around 2-4 \bm muJ at an access rate of 100 Mb/s.