Page 47 - European Energy Innovation - Spring 2016 publication
P. 47
Spring 2016 European Energy Innovation 47
COMMUNICATION
Improved energy efficiency in
WDM network elements
By Dr. Klaus Grobe, Director Global Sustainability, ADVA Optical Networking SE, Germany
INTRODUCTION Power Consumption [W]1000 10 W/Gb/s
The internet as a whole, the number 100
of its connections, their bit rates,
throughput – all of this is exponentially 10
growing now for decades. So is the 0.1 W/Gb/s
negative environmental impact of the
ICT sector. From an estimated 2% of 1 1000
the worldwide electricity production, 1 10 100
ICT is predicted to grow toward
10% beyond 2020. The increasing WDM Channel Bit Rate [Gb/s]
energy consumption creates a dual- Figure 1: Increase of WDM energy efficiency over time
fold problem. Firstly, and as long as
electricity production hasn’t been A STORY OF IMPROVING WDM energy efficiency. One can derive from
fully converted to renewable energy, ENERGY EFFICIENCY the figure that our most-recent 400-
it contributes to CO2 production. ADVA Optical Networking started Gb/s technology exceeds 0.5 W/(Gb/s)
Secondly, in the recent decades, developing WDM gear in 1994. efficiency, which for the time being is
the average energy-cost trend was For certain operational reasons – record-breaking. This was enabled, on
exclusively increasing. avoidance of the hot spots in data the basis of long-term research and
centers already mentioned – energy development, by combining latest
THE INTERNET AND WAVELENGTH- efficiency has always been a primary chip-sets, ever increasing power-
DOMAIN MULTIPLEXING concern. This is reflected by the fact supply efficiency, optimized voltage
Today, Wavelength-Domain Multiplexing that, to first approximation, the same distribution within the WDM shelves
(WDM) is the basis of all broadband number of WDM channels always and smallest form factor (the latter
wireline connectivity. Without it, the fit into one shelf, irrespective of the leading to less shelf overhead).
internet as we know it would not channel bit rate. This was only possibly
exist. It is based on independently by massively increasing the per-bit- CONCLUSION
using multiple wavelengths, each rate energy efficiency (expressed in Improvements in ICT energy efficiency
one carrying digital information, W/(Gb/s)). Research enabling this are crucial. If all relevant aspects
for capacity increase in fiber-optic improvement has been supported are considered and combined, the
transmission. Although its contribution by several EU projects, among them results necessary to avoid internet’s
to global ICT electricity consumption the projects C-3PO and the more energy-consumption explosion can
is comparatively low (routers and end- recent and ongoing CEEOALAN. be achieved. On top, proper use of
user equipment cater for the majority), These projects supported specific the internet will help reducing energy
it must improve in efficiency, too. This is photonic-components and high-speed- consumption elsewhere. l
driven by several facts. modulation aspects with special regard
to energy efficiency. CONTACT DETAILS
The internet’s ever-increasing
bandwidth appetite requires similar One result of the continuous WDM Dr. Klaus Grobe
development in efficiency (otherwise, energy-efficiency improvement is ADVA Optical Networking SE
internet’s energy consumption demonstrated in Figure 1. It shows, over Fraunhoferstr. 9a
would be exponentially increasing). bit-rate generations and that is, over 82152 Martinsried, Germany
Then, without improvements, WDM time, and for typical WDM transport KGrobe@ADVAoptical.com
equipment like some other gear as configurations, the development in
well could easily create hot spots
in data centers and similar places.
Finally, it is well-known from Life-Cycle
Analysis, that the majority of green-
house gas and some other relevant
environmental-impact factors (like
ozone depletion) is determined by the
use phase, and that is, by the energy
efficiency during the lifetime of the
respective network elements.
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