Page 8 - European Energy Innovation - Winter 2016 publication

8 Winter 2016 European Energy Innovation
COMMUNICATION

The Core-Network Energy-
Efficiency Challenge

By Dr. Klaus Grobe, Director Global Sustainability, ADVA Optical Networking SE, Germany

INTRODUCTION on technology. With Passive Optical is confirmed in so-called Life-Cycle
Bit rates in the Internet are growing Networks, growth can be kept to a Analysis (LCA), where various impact

exponentially. So is the negative minimum. aspects like GHG production, Ozone

environmental impact of the global ICT depletion and others are calculated

sector, albeit somewhat slower. This is Relevant core-network components over the entire equipment life, from

primarily driven by the Internet energy are IP/MPLS core routers and high- extracting raw materials via production,

consumption and the associated capacity transport. The latter is based transport, use-phase up to end-of-

greenhouse gases (GHG). It holds as on Wavelength-Division Multiplexing life (recycling, landfill). A simplified

long as electricity is not fully based on (WDM). In WDM, multiple wavelengths WDM LCA example is given in Figure

renewable energy. are used in optical fibers, each carrying 2, which shows the dominance of the

digital information. use-phase.

ICT energy consumption splits into

core and access networks, data centers, This started approximately 20 years The energy efficiency of core-network

and end-user equipment. There is a ago with per-wavelength bit rates equipment, in particular core routers

significant difference between core- of 2.5 Gb/s, the latest generation and WDM, has been substantially

networks and data centers on the is carrying up to 200 Gb/s per increased in the last two decades.

one hand, and end-user equipment wavelength. Although the WDM Unfortunately, the bit-rate increase –

on the other. In the recent years, the contribution to global ICT electricity throughput in core routers and WDM

energy consumption of end-user consumption is comparatively low, transport capacity – has grown even

equipment decreased globally, which WDM is one of the areas where growth faster. For both equipment categories,

was primarily driven by improvements is predicted. This is shown in Figure 1, one can approximately derive

in flat-panel displays and (laptop) where WDM contributes to Networks. duplicated energy consumption for

computers. On the other hand, core- 10-fold bit-rate increase. This is shown

network and data-center energy ICT AND THE CORE-NETWORK in Figure 3 for typical routers and WDM
consumption is commonly predicted CONTRIBUTION gear. It is relevant to note that the latest
to grow significantly. Broadband The main environmental impact from numbers in both equipment categories

access networks are also predicted core-network equipment results from are only achieved by combining the

to grow, but growth rate depends its use-phase energy consumption. This most energy-efficient measures in

all equipment aspects. This includes

Figure 1. Internet energy consumption in Germany latest chip sets, optimized voltage

[Hintemann et al., EGG 2016+, Berlin, September 2016 supply, deactivation of unused parts,

Energy Consumption [GWh/Year] 40 etc. In other words – even if the best
technologies are combined today, the
WDM LCA Example (FSP 3000)resulting efficiency increase is slightly

30 lower than the bit-rate increase. This

behavior is different as compared to

20 other equipment, e.g., computers, TV
sets etc.

10 Figure 2. Simple WDM LCA example.

0 2015 2020 2025 CO2 Other Use Phase
2010 Other Use Phase
Ozone
Smartphones, Tablets Networks Depletion

Computers Data Centers 0% 20% 40% 60% 80% 100%

Hintemann et al., EGG 2016+, Berlin, September 2016] www.europeanenergyinnovation.eu

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