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COPYRIGHT © 2012 ALCATEL-LUCENT. ALL RIGHTS RESERVED.
Ulrich Barth, Alcatel-Lucent Bell Labs
ITG Fachtagung: Zukunft der Netze, Osnabrück, September 20th, 2013
Energy Efficiency of Mobile Networks Earth / GreenTouch
COPYRIGHT © 2012 ALCATEL-LUCENT. ALL RIGHTS RESERVED.
EU Framework Program 7 project EARTH Objective: Save 50% Energy
15 Partners from 10
European countries
Funding Scheme: Large scale
Integrating Project (IP)
Total Cost: € 14.8 m
EC Contribution: € 9.5 m
Duration:
January 2010 - June 2012
Project Coordinator:
Dietrich Zeller, Alcatel- Lucent Technical Manager:
Magnus Olsson, Ericsson
https://www.ict-earth.eu
SOTARANLTEEARTHRANLTE PP ,_,_ %50
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2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
45%
30%
39%
RAN operation
Mobile devices operation and manufacturing
Data centers & data transport
2020: 0.6% of global direct CO2
0.4% of total global CO2e
2008: 0.3% of global direct CO2
0.2% of total global CO2e
Mto
nn
es
CO
2e
Worst case: No improvements
34%
Operator activities
RAN construction
19%
Continous improvement of 8% per year
Total Carbon footprint of cellular networks Life Cycle Analysis (LCA)
COPYRIGHT © 2012 ALCATEL-LUCENT. ALL RIGHTS RESERVED.
Load adaptive transceiver Principle
... ... ...
Symbols carrying signals Symbols without any signal
...
Sign
al le
vel
Time [OFDM symbol resolution]
...
Data
Data No data
LTE signal pattern on short time scale
Component sleep modes • Deactivation of all suitable components
which allow for fast reactivation
• Applied during empty LTE symbols
Component adaptation • Operating point adjustment of PA
• Applied for limited signal levels
Joint operation with energy opportunistic scheduling for maximum power saving • Scheduling for discontinuous transmission (DTX)
• Scheduling for bandwidth and capacity adaptation
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Adaptive Macro TRX Hardware Prototype Measurement results of power modes
• Proof-of-concept for energy saving by adaptive
• operation point (OP) adjustment and
• component deactivation (CD) on OFDM symbol level
PDC
PA SS-TRX
Inte
rfac
e b
oar
d
DSPC
PDC PDC
PRF,OUT
Component control
variable VDC VDC
Power supply unit
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Load adaptive transceiver for macro- BS Characteristics
Component deactivation • 55% power reduction during
deactivation • Transition times <= symbol
duration of approx. 66.7 µs
Operating point adjustment • Up to 23% power reduction • 8 operating points implemented • Transition times >> symbol
duration
deactivation activation
COPYRIGHT © 2012 ALCATEL-LUCENT. ALL RIGHTS RESERVED.
Scheduling Strategy with adaptive TRX hardware
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bo
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OFDM Symbols along 10 ms
BW Adaptationas much as possible empty subcarriers
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ad p
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ymb
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OFDM Symbols along 10 ms
CAP Adaptationas much as possible empty subcarriers
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d p
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bo
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OFDM Symbols along 10 ms
Micro DTX
as much as possibleempty symbols
Use Operation Point
adjustment
• avoid pilot overhead
Use Operation Point
adjustment
• 3GPP compliant
• channel diversity
Use Component
Deactivation
• fastest adaptation
Bandwidth Adaptation Capacity Adaptation Micro Sleeps
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Energy Aware Scheduling Results – Comparison of Scheduling Strategies
• Dense Urban Scenario
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Po
we
r Co
nsu
mp
tio
n p
er
Are
a U
nit
[k
W/k
m2]
Time [h]
SOTA BW
BW + Micro DTX CAP
CAP + Micro DTX Micro DTX
Dense Urban
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0 20 40 60 80 100
En
erg
y Sa
vin
gs [
%]
System Throughput per Area Unit [Mbps/km2]
BW CAP
Micro DTX BW + Micro DTX
CAP + Micro DTX
Dense Urban
22.1
24.6 24.9
30.5 30.6
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Dai
ly E
nerg
y Sa
ving
s [%
]
CAP
Micro DTX
BW
CAP + Micro DTX
BW + Micro DTX
Dense Urban Best approach - BW + Micro DTX (< 60 Mbps/km2) - CAP + Micro DTX (> 60 Mbps/km2) Highest daily energy savings - 30.6% for BW + Micro DTX - 30.5% for CAP + Micro DTX
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Is there an ideal deployment for EE? • Macro-cells: 3 sectors per site; intersite distance 500 m
• Heterogenous Networks: small cells (micro) support macro Macro only
HetNet, 10 micros per site
SINR distributions
0 100 200 300 400 5000
1
2
3
4
5
6
7
8
Served traffic in Mbit/s/km2
Are
a p
ow
er
in k
W/k
m2
Nmicro
=0 (6-fold)
Nmicro
=0 (3-fold)
Nmicro
=3 per macro
Nmicro
=10 per macro
Nmicro
=20 per macro
Nmicro
=30 per macro
• 80 Mbps/km2 would suggest Macro only
• 480 Mbps/km2 would suggest HetNet
• So necessary to have reconfigurable networks -> network and resource management is key
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www.greentouch.org
COPYRIGHT © 2012 ALCATEL-LUCENT. ALL RIGHTS RESERVED.
By 2015, deliver the architectures, specifications and
roadmap — and demonstrate key technologies — to
increase network energy efficiency by a factor of 1000
compared to 2010 levels and assuming service models
and traffic forecasts for the target of 2020.
2010 2015 2020
1E-4
1E-3
0.01
0.1
1
10
100
Effic
ien
cy (
Mb
/s/W
)
Year
1000x Target
Total Network: BAU
2010 2015 2020
1E-4
1E-3
0.01
0.1
1
10
100
Effic
ien
cy (
Mb
/s/W
)
Year
2010 2015 2020
1E-4
1E-3
0.01
0.1
1
10
100
Effic
ien
cy (
Mb
/s/W
)
Year
1000x Target
Total Network: BAU
GREENTOUCH MISSION
• Global research consortium representing industry, government and academic organizations
• Launched in May 2010
• 52 member organizations
• 300 individual participants from 19 countries
• 25+ projects across wireless, wireline, routing, networking and optical transmission
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Network Efficiency = Total Useful Traffic Delivered
Total Energy Consumed
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COPYRIGHT © 2012 ALCATEL-LUCENT. ALL RIGHTS RESERVED.
COPYRIGHT © 2012 ALCATEL-LUCENT. ALL RIGHTS RESERVED.
The Wireless Box GT Methodology to compute the energy consumption for
nation wide mobile networks
Traffic model:
Diverse traffic types and varied spatial-temporal
traffic distribution in the network, among the layers of equipments
The Engine of
Wireless Box
Engine Performance:
Spectrum efficiency, energy efficiency,
deployment efficiency, network throughput,
service delay, etc.
Power model:
They way power dissipates in infrastructure equipment
and the way energy consumed in the network
Deployment model:
The layout of layers of diverse network equipment
and the way they function together to serve the traffic
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Traffic Model – Area Traffic
Population density
[people/km2]
Percentage of the
total service area
Dense urban (D) 10000 0.1%
Urban (U) 1000 0.9%
Suburban (S) 300 3.0%
Rural (R) 30 26.0%
Unpopulated 0 70.0%
.
Playground: mobile network of mature
countries (group1: Western Europe,
NAR, Japan)
SU DU
DU
snapshots Overall system is comprising different types of area
• Dense urban
• Urban
• Suburban
• Rural
• Scarcely populated areas
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Level Duration [h]
20% 2
40% 4
100% 4
120% 8
140% 6
Time of day [h]
Load level
[re
lative
to
a
ve
rag
e]
Valid for all area types !
For DU area
(Shape slightly varies over areas)
PB/month Number of inhabitants GB/month/inhabitant
2010 161 878 Million 0.183
2015 3,858 878 Million 4.40
2020 14,266 878 Million 16.3
Occurance Daily Profile
Traffic Model – Daily Profile
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Deployment Model
• Deployment is specific to the area
• rural, suburban, urban, dense urban
• Base station types differ depending on service demand
• Macro, micro, pico, femto, integrated or distributed
Access NetworkAccess Network
Core Network
Gateway (PDG, GGSN)
Gateway (PDG, GGSN)
Base Station Controller (BSC)
Base Station Controller (BSC)
Media Server (IMS) Media Server (IMS)
Macro Base Station (Outdoor)
Network Server (SGSN, HLR)
Network Server (SGSN, HLR)
PSTInternet
Remote Radio Head (RRH)
Macro-Cell,
with advanced
antennas, MIMORemote Radio Head
(RRH)Remote Radio Head
(RRH)
Macro-Cell,
with advanced
antennas, MIMOMulti-Hop,
Ad-Hoc
Relais Node
Coverage Extension
with fixed Relais
Multi-Hop,
Ad-Hoc
Relais NodeRelais Node
Coverage Extension
with fixed Relais
Indoor
Indoor Coverage
with Femtos DSL Line
Home Femto
MP3
IndoorIndoor
Indoor Coverage
with Femtos DSL Line
Home FemtoHome Femto
MP3MP3 Heterogeneous
Access networks
Laptop
Micro Cellor WiMAX
Access Point
Access Network Heterogeneous
Access networks
LaptopLaptop
Micro Cellor WiMAX
Access Point
Micro Cellor WiMAX
Access Point
Access Network
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Power Model
• Power model (per BS type):
• Power consumption is characterized by a linear consumption profile with different parameters per type of base station
Pow
er
Consum
ption
(Base S
tation)
Traffic Load
Sleep mode
Minimum
energy
consumption in
active mode
2010:
648-1394 W
3dB feeder loss
no sleep mode
2020 (draft model):
157 W or 189– 665 W
(308 W at 30% load)
for small cells
2 W or 4-11 W
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Energy efficiency simulation of snapshots
• Simulation runs for all snapshots and time intervals
PHY
System Performance
Metric for single snapshot
Channel
Tx
Rx
Power model
Resource allocation
Traffic model
Deployment
PHY
Detection
L2S interface
Pout Pin
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Energy efficiency calculated from snapshots
• The average of the Energy per Mbit (E/T) is computed with the relative traffic share of the areas in the playground:
where A marks the Area Types DU, U, SU, RU and Wilderness L marks the Load Levels at Night, Morning, Average, High and Busy Hour. PA,L is the average power in scenario [A,L]
DA,L is the average data rate in scenario [A,L]
LA LA
LA
LAD
PwTE
, ,
,
,/
%10024%100,
AALLLA
onAreafracti
AveDensity
yUserdensit
h
DurationLoadlevelw
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The study
• Scenarios
• The reference scenario state-of-the art in 2010: LTE as single RAT
• The 2020 scenario best expected technology by 2020 including
standardization trends and research outside GreenTouch, e.g. EARTH
• Work in GT Mobile WG continuous to find best possible 2020 scenario applying further GreenTouch research results, e.g. LSAS, BCG, BiPON,…
2010 2020
EE
GreenTouch
1000x All mobile networks of
North America, Western
Europe and Japan
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BS deployment
abstract full-coverage LTE deployment carrying the complete wireless traffic
• legacy networks not modeled
• QoS nationwide provided
• Uniform user distribution in 2010
• 4 parallel Operators equally share traffic
• Inhomogeneous distribution in 2020
• Infrastructure sharing (single physical infrastructure)
• Adding small cells in DU
macro base station
UE
macro base station
pico base station
UE
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ISD specification
• ISD of Macro BSs is defined by typical deployed grid (2010)
• Deployment for rural areas is constrained by coverage requirements.
• Macro BSs provide sufficient capacity for 2020 U, SU, RU
• 3x2 pico cells per DU Macro BS site serve 67% of the DU traffic
• >2x overprovisioning, even with RAN sharing.
Network Layout 2010 DU
2GHz U
2GHz SU
2GHz RU
800MHz
Traffic density during Busy Hour 2010 [Mbps/km²] 2020
4 x 2 702
4 x 0.2 70
4 x 0.06 21
4 x 0.006 2.1
ISD [m] 500 1000 1732 4330
Coverage limited
Capacity exhausted in 2020
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Summary of Differences 2010 vs. 2020 scenario
2010 2020
Number of macro BSs (group1)
4 x 1 Million 1 Million (network sharing) 660,000 small BSs in DU
BS hardware 3 dB feeder loss 10MHz 2x2 MIMO 648-1394 W No power saving mode Microwave or fiber
RRHs 20MHz 8x2 MIMO 189– 665 W Micro sleep mode 157 W All fiber backhaul
Small cells None 2 per sector in DU 66.7% traffic offloaded
Spectrum usage 4 x 10 MHz @ 800MHz 4 x 10 MHz @ 2GHz
1 x 20 MHz @ 800MHz 2 x 20 MHz @ 2GHz
Traffic per person 183.4 MB/month 16.25 GB/month (88.6-fold of 2010)
!
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0
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120
140
DU DU pico U SU RU
Use
r th
rou
ghp
ut
[Mb
ps]
2020 5% 50% 95% Average
Results: User Performance (busy hour)
• DL user data rate in busy hour is in all scenarios >9Mbps
• Rates improve for 2020 due to 20 MHz 8x2 MIMO
• even though 4x less macro BSs
• resource utilisation 44% in worst scenario
0
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140
DU DU pico U SU RU
Use
r th
rou
ghp
ut
[Mb
ps]
2010 5% 50% 95% Average
N.A.
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Results: Energy Intensities
• Energy Intensity of all scenarios {A,L}. Note the 1000x larger traffic units used for 2020
EA,L/TA,L night morning average high busy hr
[J/kbit] 2010
DU 11.8 5.9 2.4 2.0 1.7
U 32.7 16.4 6.5 5.4 4.6
SU 35.2 18.2 7.3 6.0 5.1
RU 62.7 32.1 12.6 10.4 9.0
[J/Mbit] 2020
DU 9.0 4.9 2.4 2.2 1.9
U 20.9 12.1 7.2 6.6 6.3
SU 23.9 13.5 7.7 7.5 7.0
RU 36.2 20.1 10.1 9.1 8.4
733x to 1730x-
fold improvement
over all scenarios,
the averaged
efficiency gain is
1019x
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Evaluation of Results
Explanation for absolute saving inspite of 89-fold traffic:
• 4-times less macro BSs • 2.3-fold less power per BS (700W at 0.1% load vs. 300W at 25% load) • HetNet in DU (10% saving) and micro sleeps (20% saving).
Efficiency improvement 1019
Traffic increase 89
Energy saving gain 11.5
11%
24%
27%
38%
BS share
DU
U
SU
RU
28%
25%25%
22%
Traffic share
DU
U
SU
RU
10%
24%
27%
40%
Energy share 2010
DU
U
SU
RU
10%
27%
30%
33%
Energy share 2020 BAU
DU
U
SU
RU
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References
www.ict-earth.eu
“Sustainable Wireless Broadband Access to the Future Internet – The EARTH Project” for the book "The Future Internet - Future Internet Assembly 2013: Validated Results and New Horizons". The online version of this chapter can be accessed at http://www.springerlink.com/content/978-3-642-38081-5/
www.greentouch.org
„GreenTouch Green Meter Research Study: Reducing the Net Energy Consumption in Communications Networks by up to 90% by 2020“, A GreenTouch White Paper, June 2013, www.greentouch.org
O. Blume et al., „Energy Efficiency of LTE networks under traffic loads of 2020“, ISWCS 2013, Ilmenau, Germany, August 2013
COPYRIGHT © 2012 ALCATEL-LUCENT. ALL RIGHTS RESERVED.
COPYRIGHT © 2012 ALCATEL-LUCENT. ALL RIGHTS RESERVED.
Caveat
The gains of 2020 scenario must not be understood as a saving potential of network operators:
• The 2010 system is designed as a state-of-the-art LTE system with full coverage of the inhabitated regions of Group1
• cells are loaded by less than 0.3% in 2010
• can accomodated the 350-fold traffic of 2020 (88.6 x 4 ) only by adding a few small cells in DU.
• This is not the real system of 2010: Actually it requires per operator 1 Million macro BS sites for Group 1
• at least 3x the actually deployed number of BSs.
• EARTH calculted 3.3 million sites in the world for 2007 and 7.6 million in 2014
• ABI Research estimates 2.43m LTE macrocell BSs globally for 2018 and 986,000 LTE outdoor small cells.
COPYRIGHT © 2012 ALCATEL-LUCENT. ALL RIGHTS RESERVED.
Alternative Reference Scenario
• An alternative Reference scenario has been studied
• LTE rollout not using traditional ISDs
• ISD rather by coverage limitation
ISD 2010 2010 alternative
DU 500 1000
U 1000 1732
SU 1732 4330 @ 800MHz
RU 4330 @ 800MHz
6000 @ 800MHz
in total
3x times less BSs
longer transmission
distances
• Smaller gain factor
• 513x energy efficiency (vs. 1019x)
• 5.8x energy reduction (vs. 11.5x)