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Core 5 Research Programme

Green Radio – The Case for More Efficient Cellular Base StationsMay 2009

Peter GrantUniversity of Edinburghand Mobile VCE Board Member

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Presentation Overview

The Current Status on Cellular Systems

The Business Case for Green Radio

Defining the Green Radio Issues

Conclusions

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Why Green Radio?Operator & Manufacturer Perspective

Increasing energy costs with higher base station site density and energy price trends

A typical UK mobile network consumes 40MW Overall this is a small % of total UK energy consumption, but

with huge potential to save energy in other industries

Energy cost and grid availability limit growth in emerging markets (high costs for diesel generators)

Corporate Responsibility targets set to reduce carbon emissions and environmental impacts of networks

Vodafone1 - “Group target to reduce CO2 emissions by 50% by 2020, from 2006/07 levels”

Orange2: “Reduce our greenhouse emissions per customer by 20% between 2006 and 2020”

1. http://www.vodafone.com/etc/medialib/attachments/cr_downloads.Par.25114.File.tmp/CR%20REPORT_UK-FINAL%20ONLINE_180908_V6.pdf2. http://www.orange.com/en_EN/tools/boxes/documents/att00005072/CSR_report_2007.pdf

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Where is the Energy Used?

For the operator, 57% of electricity use is in radio access

Operating electricity is the dominant energy requirement at base stations

For user devices, most of the energy used is due to manufacturing

RBS57%

Retail2%

Core15%

Data Centre6%

MTX20%

9kg CO2

4.3kg CO2

2.6kg CO2

8.1kg CO2

Mobile

CO2 emissions per subscriber per year3

Operation

Embodied energy

Base station

3. Tomas Edler, Green Base Stations – How to Minimize CO2

Emission in Operator Networks, Ericsson, Bath Base Station Conference 2008

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UK Operator GSM + 3G Network Consumption

Source: CR review, Vodafone UK, Corporate Responsibility 2007/08

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GSM + 3G Cellular Network Emissions??

Source: CR review, Vodafone UK, Corporate Responsibility 2007/08

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Retail

Data Centre

Core Transmission

Base Stations

0% 10% 20% 30% 40% 50% 60%

Mobile Switching

Source: Vodafone

Cellular Network Power Consumption Summary(from previous pie chart)

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Base Station Power Use @ 2003

Transceiver Idling 19%

Power Amplifier 22%

Cabling 1%

Transmit Power 3%

Central Equipment 8%

Combining/Duplexing 9%

Transceiver Power Conversion 9%

Cooling Fans 13%

Power Supply 16%

H. Karl, “An overview of energy-efficiency techniques for mobile communication systems,” Telecommunication Networks Group, Technical University Berlin, Tech. Rep. TKN-03-XXX, September 2003. [Online]. Available: http://www-tkn.ee.tu-berlin.de/ karl/WG7/AG7Mobikom-∼EnergyEfficiency-v1.0.pdf

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Power Consumption

Now (Possible)

Target (2010)

GSM

800W

650W

WCDMA

500W

300W

Source: NSN

Power Consumption per BS

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Energy Consumption

The Base Station is the most energy–intensive component of a 3G mobile network.

A typical 3G Base Station consumes about 500 W with a output power of ~40 W. This makes the average annual energy consumption of a BS around 4.5 MWh (which is lower than a GSM BS).

!A 3G mobile network with 12,000 BSs will consume over 50 GWh p.a. This not only responsible for a large amount CO2 emission and it also increases the system OPEX.

This is 10X consumption of a UK broadcast TV network

This is worse in China with 10-20 times number of mobile subscribers!

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Energy Consumption – The Challenge

Since 2006, the growth rate of data traffic on mobile networks has been approximately 400% p.a.. It is expected to grow at least the same rate in coming years.

This growth demands a much higher energy consumption than today.

The challenge is how to design future mobile networks to be more energy efficient to accommodate the extra traffic.

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Energy use cannot follow traffic growth without significant increase in energy consumption

Must reduce energy use per data bit carried

Number of base stations increasing Operating power per cell must reduce

Green radio is a key enabler for cellular growth while guarding against increased environmental impact

Green Radio as an Enabler

Co

sts

Time

VoiceData

Revenue

TrafficDiverging expectations for traffic and revenue growth

Trends:

Exponential growth in data traffic

Number of base stations / area increasing for higher capacity

Revenue growth constrained and dependent on new services

Traffic / revenue curve from “The Mobile Broadband Vision - How to make LTE a success”, Frank Meywerk, Senior Vice President Radio Networks, T-Mobile Germany, LTE World Summit, November 2008, London

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2020 Vision Paper – The Challenge

The Mobile VCE Visions Group comprising global thoughts leaders in the industry articulated the need….

“Arguably what is needed are wireless access systems that can support multimedia service data rates attwo or three orders of magnitude lower transmission power than currently used. Performance of today’s radio access technologies is in fact already approaching the Shannon Bound – such an advance will not come simply from more traditional research on single aspects of the physical layer, but will require holistic, system-wide, breakthrough thinking that challenges basic assumptions” Mobile VCE consultation paper, “2020 Vision – Enabling the Digital Future” Dec’07

Mobile VCE Green Radio programme formulated to: Take forward existing research

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Broadband Traffic on Mobile Networks

Revenue increase is not in line with traffic growth*

Average annual increase in traffic: 400% Average annual increase in revenue: 23%

With the launch of HSDPA and the introduction of flat-rate pricing, data traffic is increasing

Traffic is growing faster than the revenue increase

The biggest traffic growth is seen at operators whose data pricing is more aggressive than the average

*Source: Stanley Chia, Workshop on “As the Internet takes to the air, do mobile revenue go sky high?,” IEEE Wireless Communications and Networking Conference, April 2008.

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Possible Solutions Green Radio

Can we benefit from the use of the information below in the design of future mobile networks?: Mobility pattern (location, speed and direction of mobile

user) information Characteristic of multimedia traffic (traffic classification)

Transmission power scaling (distribution) in order to use renewable energy for BSs.

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Green Radio ScenariosTwo Market Profiles:

1. Developed World Developed Infrastructure Saturated Markets Quality of Service Key Issue Drive is to Reduce Costs

2. Emerging Markets Less Established Infrastructure Rapidly Expanding Markets Large Geographical Areas Often no mains power supply

– power consumption a major issue

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Over a year, 1m2 solar panel produces ~400 kWh energy, or about 10% of a 3G macrocell BS requirement (in London, < 5%).

Note that we never recover the embodied or manufacturing energy!

A combination of solar & wind sources, in a good location may provide the energy requirement for a small (pico-femto) BS ?

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Industry Subscription/Gvt

funded Collaboration

Core 5 research programme,

2009 – 2012 targets:

1. Green Radio

2. Flexible Networks

3. User interactions

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GR Industrial Leadership Team

ChairmanSimon Fletcher NEC

Deputy Chairman Andy Jeffries Nortel

Industry Steering Group – participants so far…

Deputy ChairmanDavid Lister Vodafone

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GR Academic Leadership Team

Prof. Joe McGeehanDr. Simon ArmourDr. Kevin Morris

Prof. Hamid AghvamiDr. Mohammad Reza NakhaiDr. Vasilis Friderikos

Prof. Steve McLaughlin(Academic Co-ordinator)Dr. John ThompsonDr. Dave Laurenson

Prof. Tim O'FarrellDr. Pavel LoskotDr. Jianhua He

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Green Radio Programme Organisation

Industry Steering Group

Flexible Networks Program

2 Technical Work Areas - 48 Man Years

GR2: Techniques2 PDRAs, 7 PhDs

To identify the best radio techniques across all layers

of the protocol stack that collectively can achieve

100x power reduction

GR1: Architecture2 PDRAs, 5 PhDs

To identify a green network architecture - a low power wireless network & backhaul

that still provides good quality of service

Energy Focus Group

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1. Conventional Cellular

Reducing Power Consumption Through Delay-Tolerant Networking

WLAN

FixedRelay

FemtoCell

Node BContent Server

MobileRelay

2. In-BuildingRelay

3. Multi-hopRelay

4. HeterogeneousRelay

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Conclusion

Growth in data transmission requirements for mobile broadband will not bring major revenue increase.

Every industry has published CO2 reduction targets and the mobile and IT communities are not exempt.

Power drain in base-station or access point is the major issue in many wireless systems.

Green Radio promised to deliver benefit to the Cellular network Operators via the equipment supply chain vendors.

We plan to research and investigate changes to the system architecture and develop advanced networking techniques to deliver these future more efficient Green Radio systems.

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© 2009 Mobile VCE

Thank you !

For Green Radio please contact: Simon FletcherE-mail: Simon.Fletcher@EU.NEC.COMTel: +44 1372 381824

or Steve McLaughlin Steve.McLaughlin@ed.ac.uk +44 131 650 5578

Further information on MobileVCE contact:Dr Walter Tuttlebee,E-mail:

walter.tuttlebee@mobilevce.comTel: +44 1256 338604WWW: www.mobilevce.com