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© 2009 Mobile VCE

Core 5 Programme

Green Radio – Towards Sustainable Wireless NetworksApril 2009

Peter GrantUoE and Board MemberSteve McLaughlinUoE and Academic Co-ordinatorHamid AghvamiKCL and Board MemberSimon Fletcher

NEC and Industrial Steering Group Chair

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© 2009 Mobile VCE

Presentation Overview

� The Current Status on Cellular Systems

� The Business Case for Green Radio

� Defining the Green Radio Issues

� The Mobile VCE Research Programme

� Research Areas and Key Deliverables

� Conclusions

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© 2009 Mobile VCE

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.pdf

2. http://www.orange.com/en_EN/tools/boxes/documents/att00005072/CSR_report_2007.pdf

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© 2009 Mobile VCE

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

RBS

57%

Retail

2%

Core

15%

Data Centre

6%

MTX

20%

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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© 2009 Mobile VCE

UK Operator GSM + 3G Network Consumption

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

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© 2009 Mobile VCE

GSM + 3G Cellular Network Emissions??

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

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© 2009 Mobile VCE

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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© 2009 Mobile VCE

Base Station Power Use

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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© 2009 Mobile VCE

Power Consumption

Now (Possible)

Target (2010)

GSM

800W

650W

WCDMA

500W

300W

Source: NSN

Power Consumption per BS

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© 2009 Mobile VCE

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.

This is 10X consumption of a UK broadcast TV network!

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 worse for China with 10-20 times number of mobile subscribers!

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© 2009 Mobile VCE

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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© 2009 Mobile VCE

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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© 2009 Mobile VCE

2020 Vision Paper – The Challenge

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

“Arguably what is needed are wireless access systemsthat can support multimedia service data rates at

two 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

� Aim to achieve an international lead in this field

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© 2009 Mobile VCE

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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© 2009 Mobile VCE

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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© 2009 Mobile VCE

Green Radio Scenarios

Two 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

Green Radio MVCE ‘Book of Assumptions’:

� Defines cellular, enterprise & home scenarios

� To galvanise targeted innovations

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© 2009 Mobile VCE

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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© 2009 Mobile VCE

Industry Subscription/Gvt

funded Collaboration

Core 4, 2006 – 2008:

Efficiency, Ubiquitous

Core 4 cont., 2009 – 2011:

Instant Knowledge (Security)

Core 5, 2009 – 2012:

1. Green Radio

2. Flexible Networks

3. User interactions

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© 2009 Mobile VCE

GR Industrial Leadership Team

� Chairman

Simon Fletcher

NEC

� Deputy Chairman

Andy Jeffries

Nortel

Industry Steering Group – participants so far…

� Deputy Chairman

David Lister

Vodafone

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© 2009 Mobile VCE

GR Academic Leadership Team

Prof. Joe McGeehanDr. Simon Armour

Dr. Kevin Morris

Prof. Hamid Aghvami

Dr. Mohammad Reza Nakhai

Dr. Vasilis Friderikos

Prof. Steve McLaughlin(Academic Co-ordinator)Dr. John Thompson

Dr. Dave Laurenson

Prof. Tim O'FarrellDr. Pavel Loskot

Dr. Jianhua He

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© 2009 Mobile VCE

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 powerwireless network & backhaul

that still provides good quality of service

Energy Focus Group

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© 2009 Mobile VCE

Target Innovations: Architecture

Establishing Baselines To develop a clear understanding of energy consumption in current networks and the network elements, base sites, mobiles, etc for the scenarios defined in the Book of Assumptions

Backhaul Options To determine the best backhaul strategy for a given architecture

Deployment ScenariosTo determine what is the optimum deployment scenario for a wide area network given a clearly defined energy efficiency metric

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© 2009 Mobile VCE

Architecture: Technical Approach

Energy Metrics & Models

� Primary and derived energy metrics to accurately quantify consumption

� Communications energy consumption models for the radio access network (RAN) architecture

Energy Efficient Architectures

� For RAN technology, compare large versus small cell deployment

� Assess scenarios for placement of relay nodes

� Efficient backhaul in support of identified architectures

Multi-hop Routing

� Bounding energy requirements by strict end-to-end QoS

� Exploiting delay tolerant applications and user mobility for energy reduction

Frequency Management

� Identification of energy efficient co-operative physical layer architecture using emerging information theory ideas to remove interference

� Applying Dynamic Spectrum Access (DSA) to minimize energy consumption by utilising bands with low interference

� Solar-powered relaying allocating resources to match combined traffic and weather patterns

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© 2009 Mobile VCE

Architecture:Energy Efficiency Analysis

Macro Micro Pico Femto

RRM

BER/FER vs Eb/No

Link Budget

Mobility/Traffic Models

Packet scheduling, handover, power and load control

Differentiated QoS, fast fading effects, UE speed, MIMO

Energy consumption is proportional to distance

User Equip (UE) movement, traffic types & mixes

Step1: Large vs. small cells applying the energy metrics

Step2: Overlay Source & Network Coding and/or Cooperative Networking

Step3: Evaluate optimum cell size from the following perspectives…….

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© 2009 Mobile VCE

1. Conventional

Cellular

Reducing Power Consumption Through Delay-Tolerant Networking

Fixed

Relay

Mobile

Relay

2. In-BuildingRelay

3. Multi-hopRelay

4. HeterogeneousRelay

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© 2009 Mobile VCE

Applying Network Element Deployment Perspective

Wide scope: Macro-cells, relays, backhaul, WLAN.Also consider Embodied (Equipment Fabrication) Energy.

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© 2009 Mobile VCE

33 month Task:

researchers split

to 3 areas

GR1-3:Multihop

6.25 MY

GR1: Architecture

GR1-1:Key Metrics

& Architecture3.5 MY

9 month Task:

All researchers

participate

Selection of Key

Metrics & Initial

Results on Efficient

ArchitecturesGR1-2:

Energy Efficient Architectures

8.75 MY

GR1-4:Frequency

Management3.75 MY

GR1-2 Performs

Overall Architecture

Assessment

GR1-3 and 1-4

Address More

Specific Issues

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© 2009 Mobile VCE

Target Innovations: Techniques

Overall Base Station EfficiencyTechniques to deliver significant improvements in overall efficiency for base stations, measured as RF power out to total input power

Improving the QoS/RF Power RatioReduce the required RF output power required from the base station whilst still maintaining the required QoS

Optimization of a Limited Energy Budget Given a base station nominal daily energy requirement derived from renewable energy sources (e.g. 2.4 kWh -100W x 24hrs) determine how this would be best used for communication

Scaling of Energy Needs with Traffic Sleep mechanisms that deliver substantial reduction in power consumption for base stations with low loads and develop techniques that allow power consumption to scale with load

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© 2009 Mobile VCE

Techniques: Power Efficient Hardware

3G Base station efficiency� Climate control 65%

� Power supply 85%

� PA / transceiver 45%

� Feeder cables 50%

Advanced base station architectures� Multi-mode and multi-standard

� Maximise equipment and base station re-use

Integration allows energy reductions

� Masthead electronics avoids cable losses

� Target > 20% overall efficiency

Advanced power amplifier techniques� Target: > 60% PA efficiency

� Develop envelope tracking method

Hardware Integration & Advanced PA Techniques

Baseline overall

efficiency 12%

Integrated remote radio antenna

� Masthead PA eliminates feeder loss

� Integration avoids interconnect losses

� Passive thermal cooling

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© 2009 Mobile VCE

Techniques: DSP and Radio Resource Management

Interference Minimisation and Cancellation� Making transmissions more robust to interference to reduce

required transmit power levels

� Peer-to-peer communications between terminals can be exploited to share information about signals and interference toimprove decoding and suppress interference

RRM Techniques for Lower Power Consumption� Maximising power efficient utilisation of LTE RBS co-operation

and collaboration support.

� Robust Measurement reporting, Radio Bearer Configuration, Packet Scheduling, handover and Power and Load Control for energy efficient delivery

Novel Approaches� Network coding

� Application of Sensor network techniques, cross layer approaches grounded in standards (LTE, WiMAX)

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© 2009 Mobile VCE

GR2-5 Allows for

Top-Down “System”

Perspective

GR2-2:Resource

Management7 MY

GR2: Techniques

GR2-1:Investigation & Evaluation

4.5 MY

9 month Task:

Involves All

researchers

Identify Novel

Approaches using

standard RBS/AP as

baseline to improve

GR2-5:Novel Techniques

for Power Reduction~ 4.25 MY

GR2-4:Efficient Hardware

5 MY

GR2-3:Efficient

DSP6.5 MY

This task can vary in

size according to

results from GR2-1

GR2-2, 2-3 and 2-4 Address

Techniques across Protocol Stack

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© 2009 Mobile VCE

Green Radio Deliverables

Year 1

� Workshop to discuss architecture metrics and promising techniques for power reduction

� Executive Summary on energy and power efficiency metrics and tradeoffs

Year 2

� Poster day presenting key results to date

� Reports on efficiency gains

Year 3

� Reports on Programme achievements for both Architectures and Techniques Work Packages

� Executive summaries of all key outputs from the Programme

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© 2009 Mobile VCE

Our Process - engagement with Industrial Sponsors

� Monthly Co-ordination Steering Group (CSG) meetings� Progress management (deliverables, patents, publications)

� Internal and outreach event organisation

� Quarterly Technical Steering Group (TSG) meetings

� Meetings at which all Industrials have the opportunity to engagewith the Researchers on the detail of their research results

� Interdependent approach facilitated by well established MVCE processes with Core 5 enhancements

� Encouraging exploration of synergies with Flexible Networks. Both programmes contain activities in…

� Network coding, routing, adaptive and self-organisation

� Webex – Internet-based interactions between Researchers and Industrials, especially valuable for overseas-based industrials

� WiKi - promoting high awareness of leading edge of key radio access standards: LTE(-Advanced), 802.16 (WiMAX), 802.11 (Wi-Fi) and leading edge green technologies through the WiKi

� Industrial Energy Focus Group leading the embodied energy debate

� Open publication (after review), build patent portfolio for royalty free access by our sponsors plus external exploitation

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© 2009 Mobile VCE

Energy Focus Group Concept

� Terms of Reference� Initially tightly coupled to Architecture Research Group

� Evolution of targeted questions

� Analysis abstraction for realistic industrial application

� What ‘energy’ metrics do we use to ensure realistic configurations & architectures result

Problem AbstractionProblem Abstraction

Relate to Real WorldRelate to Real World

Metrics / Metrics / OptimisationOptimisation

Real WorldReal World

Targeted Targeted

QuestionsQuestions

Book of Book of AssumptionsAssumptions

MetricsMetrics

Real World Real World

System System ParametersParameters

Evaluation Evaluation ApproachApproach

Architecture StudyArchitecture Study

Real World Real World CostsCosts

Real World Real World MetricsMetrics

Real World Real World ConstraintsConstraints

Energy Focus Group

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© 2009 Mobile VCE

Example Meetings Diary for 2009

� For our Members and Researchers

� Education Day: 30th April

� To brief the researchers on the state of the art in industry and bring everyone up to speed on the Programme.

� Industry Quarterly Steering Group TSG#3: 2nd July

� Metrics Workshop: 9th September

� Review meeting for a key deliverable from the Architecture Research, all are welcome.

� Industry Steering Group TSG#4: 1st October

� Outreach Events

� Event prior to WWRF: 4th May at FT-Orange, Paris

� Support for Femto Forum Research Day:

� Aligned with the Femtocells World Summit, June 23rd - 25th, London

� Discussions ongoing with the Femtoforum.

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© 2009 Mobile VCE

Conclusions

�Green technologies relevance to business and politics will only continue to increase, Green Radio offers timely Industry driven research.

�Green Radio is a 48 man year programme run over 3 years that offers…�An in-depth and systematic study of architecture issues

to identify trade-offs in energy efficient network design

�Evaluation of Techniques across the protocol stack to select most promising approaches to reduce power.

�Green Radio will provide insights of value to…�Operators considering the impact of Green for future

networks deployments

�Equipment Vendors for identification of key techniques enabling green solutions.

www.mobilevce.com

© 2009 Mobile VCE

Thank you !

For further information please contact: Simon Fletcher

E-mail: Simon.Fletcher@EU.NEC.COMTel: +44 1372 381824or 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