1Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Green Wireless Telecommunications
Dr. Laurent Hérault
CEA-LETI
Business Development Manager
2Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Outline
�Energy efficiency of ICT & mobile communications
�Sustainable mobile networks solutions�Holistic approach�Green metrics�Green radios�Green networks�Green communications for an EE society
�Conclusions
5 billion people
connected
3Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
“We simply must do everything we can in our power to slow down global warming before it is
too late. The science is clear. The global warming debate is over.”
Arnold Schwarzenegger, Governor of California
“The IPCC has unequivocally affirmed the warming of our climate system, and linked it directly to human activity (greenhouse gas
emissions).”Ban Ki-moon, UN Secretary-General
4Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
The Issue (1/2)
� Currently, 3 % of the world-wide energy is consumed by the ICT infrastructure � which causes about 2 % of the world-
wide CO2 emissions� comparable to the world-wide CO2
emissions by airplanes or ¼ of the world-wide CO2 emissions by cars
� The transmitted data volume increases approximately by a factor of 10 every 5 years
5Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
The Issue (2/2)
� ICT: 10% of electrical energy in industrialized nations� 900 Bill.. kWh / year = Central and
South Americas
� Power consumption of ICT is currently rising at 16-20% / year � Doubling every 4-5 years
� Wireless communications are used extensively to save energy in other industrial sectors.
6Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
ICT use: worldwide today
� Total = 156 GW ~ 8% of the global electricity consu mption� No dominating front
Sou
rce:
Ghe
nt U
nive
rsity
/IB
BT
7Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
ICT: Future estimations
� 1/7th of electricity goes to ICT use phase in 2020
� The GESI Smart 2020 report* predicts growth in ICTs p ower requirement of 70% over the period 2007-2020
* Global e-Sustainability Initiative / www.smart2 020.org
Sou
rce:
Ghe
nt U
nive
rsity
/IB
BT
8Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
EE & Mobile networks
� So far, mobile networks design rules have ignored EE� Cellular networks have been
optimized in terms of spectral efficiency, capacity or throughput, not really in terms of Energy Efficiency!
� EE consideration mainly for mobiles� EE considered only for high load
scenarios
� Long-term vision: sustainable energy powered micro/femto base stations
� Emerging IoT / RWI raises green challenges
9Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Power consumption of cellular networks
Users
1kW 10kW0,1W
3 million x 1.5kW4,5GW
3 billion0,2-0,4GW
10.000 x 10kW0,1GW
~20Mt CO2/a
~1-2Mt CO2/a
~0,5Mt CO2/a
Mobile CS Core
Mobile PS Core
Transport
IP Core
BTS
~90% = Operator OPEX
Sou
rce:
NS
N
10Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Power consumption of cellular networks & Internet of Things
Users
1kW0,1W
3 million x 1.5kW4,5GW
3 billion0,2-0,4GW
~20Mt CO2/a
~1-2Mt CO2/a
BTS
~90% = Operator OPEX
0,02W
IoT, M2M
300-10000 billion6 - 200 GW
LETI0,005W / ZigBee
Battery-free sensors
11Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
EE & Mobile networks
� Mobile operators are already today among the top en ergy consumers� Telecom Italia (fixed & mobile) is the 2nd largest energy consumer in
Italy
� Energy consumption of Mobile Networks is growing much faster than ICT on the whole� Rapid traffic growth and build-up of broadband coverage� Mobile replacing fixed in many areas� Enabling ICT services for energy saving in other sectors
(teleconferencing,...) further increases mobile networks growth
Annual growth rate of internet traffic is 85%.
12Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Power consumption of a traditional cellular site
60W1500W
Backup system
Dieselgenerator Battery
Air conditioningCooling
Rectifier
Site support system
Mains(230V)
Only ~4% of the consumed power transmitted
50% energy lost(Feeder cable)
1000W 120W
35% energy lost(Site support)
Sou
rce:
NS
N
13Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Power consumption of a modern cellular site
60W500W
Backupsystem
Rectifier
Site supportsystem
Mains(230V)
~12% of the consumed power transmitted
120W
430W
14% energy lost(Site support)
50% energy lost(Feeder cable)
Sou
rce:
NS
N
14Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Outline
�Energy efficiency of ICT & mobile communications
�Sustainable mobile networks solutions�Holistic approach�Green metrics�Green radios�Green networks�Green communications for an EE society
�Conclusions
5 billion people
connected
15Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
LETI in the European Community
� « Green Communications »eMobility Working Group & white paper
� 1st International Workshop on Green Wireless Communications 2008, 2009
� ICC’Green Coms WS’09
� IST IP SENSEI -> WSNs (FP7 Call 1)
� EUREKA CATRENE PANAMA� 1 IP + 1 STREP in FP7 Call 4
16Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
EE mobile networks require an holistic approach
Reference scenarios
• Deployment strategies
• Cooperation schemes
• PHY layer parameters
• Transceiver architectures& components
• Traffic patterns
• User densities• Higher layer strategies
EE Metrics?
… from semiconductor technology to radios and networ ks
17Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Mobile networks
� Large savings potential not only for quiet hours. Network load is not evenly distributed� Typically 10% of the sites carry 50% of all
traffic.
� 50% of sites are lightly loaded, carrying only 5% of the traffic.
� Energy savings should be considered primarily at the network level� NTT DOCOMO have calculated that, for their
52 million subscribers in 2006, the energy consumption of their network per mobile user per day was 120 times greater thanthe daily energy consumption of a typical user’s mobile phone .
18Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
EE Metrics
� Metrics should be defined to measure energy consumption (in e.g. Wh or Joule) on component, node and system/network levels, in relation to delivered QoS and system spectral efficiency
BS sub-
component
EE m
etric
BS EE
metric
Site EE
metric
Network
EE
metric
Global metric
PHY layerCircuitry MAC / higher layers …
Tx Rx SignallingSignalprocessing
Access scheme Cooperation
System level
Component level
Energy consumption Spectral efficiency QoS requirements
19Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Towards Green Radios
Energy Efficiency EnablingRadio Interface Techniques
Integrated optimisation considering
component, radio andinterface to network-level
• Base station power adaptation
• Sleep mode and associated signalling• Transmission mode adaptation
• Dynamic load adaptation• Cross layer optimisation
EE Technologies and Components
Power scalable
transceivers
Power control on
component, front -end and system
level
Adaptable matching
networks
EE Application of Innovative Radio Transmission
Techniques
• MIMO
• Adaptive antennas• Coordinated multi -points
• Advanced retransmission
20Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Innovations in RF front-end architectures
� Design flexible architectures with new components�MEMS to have better perf. (filtering)
with lower consumption
� Tune performances at run time to the required flexibility & reconfigurability
� Co-design of PAs and LNAs� Better performance (BW a gain) for a
given current� Lower current for given performance
� Avoid losses in the chain� Best matching between amplifiers and
the antenna� Use of PA in their non linear domain +
predistorsion techniques & digital compensation (Tx or Rx)
21Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Innovations in digital BB architectures
� Multi-User MIMO
� Manage multiple standards in the terminal� Complex & dense digital
partitioned NoC (network on chip / multi-cores)
� Use of DFVS in GALS systems, i.e. Tuning of local power supply units & clock generators
� Run full frequency only when required
� Master leakages� Leakage currents represent up to
25% of the power consumption with submicron technos
• Spatial dimensions assigned to several users.
• Separation of users by TDMA, FDMA and SDMA.
22Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Towards Green Networks (1/4)
� Deployment scenarios:� optimum cell sizes
� mix of cell sizes� hierarchical deployments
� multi-RAT deployments� relays & repeaters
Deployment
overlay macro cell
smallcells
relays
EE topology
23Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Towards Green Networks (2/4)
� Management algorithms:� coverage adjustment� capacity management�multi-RAT coordination� base station sleep mode� protocol design
Management
multi-RAT
EE adaptive cov./cap.
Zzz
24Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Towards Green Networks (3/4)
� RRM algorithms:� cooperative scheduling� interference coordination� joint power allocation and
resource allocation�EE vs. spectral efficiency
RRM
EE joint RRM
25Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Towards Green Networks (4/4)
� Disruptive approaches:�multi-hop transmission� ad-hoc networks� terminal-terminal-
transmission� cooperative multipoint arch.�EE adaptive backhauling� cognitive/opportunistic
radios & networks
New Architecture
Adaptivebackhaul
multi-hop
Future EE architectures
26Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Some disruptive power saving strategies
short range cooperative clusters in homogeneous networks
exploiting heterogeneous RATs
� Use of cognitive radios and networks
27Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
System level simulations
� Green metrics� Evaluation of green algorithms & protocols
28Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Integration and testing
Integration and testingIntegration and testingDefinition of the validation procedures
Define the validation platform
Define the rules and the activities for the integration in the test bed
Block 1
divider
Device 2
a
c
Signal Generator
out in out in
b
1111
3333
2222
divider
divider
Ch 1 Ch 2
Block 1
divider
Device 2
a
c
Signal Generator
out in out in
b
1111
3333
2222
divider
divider
Ch 1 Ch 2
Test Plant
29Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
ICT can help society
� ICT has the potential to reduce society’s CO2 emissions (carbon footprint) by 5% - 20% in the short to medium term
� ICT is a cornerstone ina low-carbon economy
1800 1850 1900 1950 2000 2050
EU goal(-80%)
Currentdirection
ICT red.5% - 20%
30Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Just how can ICT help society?
Source: GESI / Smart2020 report, 2008
Dematerialisation
31Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Conclusion and outlook
� Significant energy savings can be expected� by defining and standardizing EE
metrics, � combining energy aware flexible
radios and networks, and� using wireless technologies in many
sectors.
� LETI is working on promising road blocks
32Laurent Hérault, 20 June 2009 11th Leti Annual Review 2009 Copyright 2009 CEA-LETI
Thank you …