From this month's
The Power of Wireless Cloud: An analysis of the energy consumption of wireless cloud [
PDF], a white paper by the Centre for Energy-Efficient
Telecommunications (CEET) at Melbourne University -
Previous analysis and industry focus has missed the
point: access networks, not data centres, are the biggest
threat to the sustainability of cloud services. This is
because more people are accessing cloud services
via wireless networks. These networks are inherently
energy inefficient and a disproportionate contributor to
cloud energy consumption.
Cloud computing has rapidly emerged as the driving
trend in global Internet services. It is being promoted as
a green technology that can significantly reduce energy
consumption by centralising the computing power of
organisations that manage large IT systems and devices.
The substantial energy savings available to organisations
moving their ICT services into the cloud has been the
subject of several recent white papers.
Another trend that continues unabated is the take-up
and use of personal wireless communications devices.
These include mobile phones, wireless-enabled
laptops, smartphones and tablets. In fact, tablets don’t
accommodate a traditional cable connection; rather it is
assumed a local or mobile wireless connection will be used
to support all data transferred to and from the device.
There is a significant emerging convergence between
cloud computing and wireless communication, providing
consumers with access to a vast array of cloud applications
and services with the convenience of anywhere, anytime,
any network functionality from the device of their choice.
These are services many of us use every day like Google
Apps, Office 365, Amazon Web Services (AWS), Facebook,
Zoho cloud office suite, and many more.
To date, discussion about the energy efficiency of cloud
services has focussed on data centres, the facilities used to
store and serve the massive amounts of data underpinning
these services. The substantial energy consumption of data
centres is undeniable and has been the subject of recent
high-profile reports including the Greenpeace report, How
Clean is Your Cloud.
However, focussing cloud efficiency debate on data centres
alone obscures a more significant and complex problem
and avoids the critical issue of inefficiency in the wireless access network
Data centres are only part of a much larger cloud-computing
ecosystem. In fact, as this white paper puts forward,
the network itself, and specifically the final link between
telecommunications infrastructure and user device is by far
the dominant and most concerning drain on energy in the
entire cloud system.
Based on current trends, wireless access technologies such
as WiFi (utilising fibre and copper wireline infrastructure)
and 4G LTE (cellular technology) will soon be the dominant
methods for accessing cloud services. ‘Wireless cloud’ is a
surging sector with implications that cannot be ignored.
Our energy calculations show that by 2015, wireless cloud
will consume up to 43 TWh, compared to only 9.2 TWh in
2012, an increase of 460%. This is an increase in carbon
footprint from 6 megatonnes of CO2 in 2012 to up to 30
megatonnes of CO2 in 2015, the equivalent of adding 4.9
million cars to the roads. Up to 90% of this consumption is
attributable to wireless access network technologies, data
centres account for only 9%.
Curbing the user convenience provided by wireless access
seems unlikely and therefor the ICT sector faces a major
challenge. Finding solutions to the ‘dirty cloud’ at the very
least requires a broader acknowledgment of the cloud
computing ecosystem and each components’ energy
requirements. There needs to be a focus on making access
technologies more efficient and potentially a reworking of
how the industry manages data and designs the entire
global network.
This white paper sets out to establish a starting point for
addressing these issues, presenting a detailed model
that estimates the energy consumption of wireless cloud
services in 2015 taking into account all of the components required to deliver those services.
The authors conclude -
Cloud computing is widely viewed as the next major
evolutionary step for the Internet and Internet-based
services. The shift to wireless access is also continuing
at a great rate. Cisco projects that cloud computing will
represent approximately 34% of data centre traffic in 2015
[3], with approximately 20% of data centre traffic will be
served by wireless access networks.
Wireless and cloud are converging trends supported by
the increased availability of affordable, powerful portable
devices, convenient and useful applications, and highspeed
wireless broadband infrastructure. This convergence
is expected to be a key driver of traffic growth on
telecommunications networks in the future.
There is evidence to show that cloud services access
via fixed-line networks could result in lower energy
consumption relative to current computing arrangements,
such as replacing powerful desktop computers with cloud
services [9,10,11]. Greenpeace has highlighted the carbon
footprint of cloud computing but focused on data centres
as being the biggest contributor to energy consumption.
When considering the energy consumption of the wireless
cloud, all aspects of the cloud ecosystem must be taken
into account, including end-user devices, broadband access
technology, metro and core networks, as well as data
centres.
This white paper analysed the various components of the
wireless cloud ecosystem to identify the dominant energy
consumers. The CEET model explored the impact of the
wireless cloud, accounting for all aspects of the ecosystem
including devices, broadband access technology, and metro
and core telecommunications, in addition to data centres.
The predicted large-scale take-up of wireless cloud
services will consume 32 to 43 TWh by 2015. The energy
consumption of wireless access dominates data centre
consumption by a significant margin.
To ensure the energy sustainability of future wireless
cloud services, there needs to be a strong focus on the
part of the ecosystem that consumes the most energy:
wireless access networks. Further debate needs to move
beyond the data centre to develop a holistic account of
the ecosystem with this white paper being a step in that
direction.
