Energy Performance | Public | © Ericsson AB 2017 | 2017-11-23 | Page 1

5G NetworkEnergy performance

Dr. Pål Frenger, Ericsson Research, 2017-11-14

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Network energy performance

Minimizing total network energy consumption, despite increased traffic and service expansion

Economy Ecology Engineering

Energy Performance | © Ericsson AB 2017 | Public | 2017-11-23

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The big picture

4G

3G

2G1G~20% ~80%

RANCore / IP

Dominating parts:• RAN: macro base stations• Macro base stations: radio power amplifier

Energy Performance | Public | © Ericsson AB 2017 | 2017-11-23 | Page 4

What will happen with 5G?

2G

3G

4G

5G

…Or can we

do better?

Business

As Usual

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NR Energy Performance

Load adaptive

energy consumption

Only transmit when

and where needed

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Energy Performance | Public | © Ericsson AB 2017 | 2017-11-23 | Page 6© Ericsson AB 2017

5G NR Key Features for enhanced

Network Energy Performance

› Ultra-lean design– Large sleep ratio and long sleep duration– Less interference � Higher peak-rates– Separation of active and idle mode functions

› Massive MIMO beam-forming– Increased range � Fewer sites

– Higher capacity � Fewer sites– Higher rates � More sleep

Active

ActiveActive

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Networks dimensioned for peak traffic demand

Network Traffic Load50%40%30%20%10%0%

Network Energy Consumption

Normal traffic Very high traffic Extreme traffic

Low average resourceutilization

Considerable static energyconsumption in networks

Improve load dependence!

LTE Traffic vs energy consumption

Normal traffic Very high traffic Extreme traffic

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Micro sleep TX – Cell DTX

RF output power

Full load

Active

RBS power usage

Ref. Symbols, Sync, Sys Info

“Empty LTE radio Frame”

Time (10 ms)

Fre

quen

cy (

6 P

RB

)

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Micro sleep TX – Cell DTX

RF output power

Full load

Active

RBS power usage

Ref. Symbols, Sync, Sys Info

Sleep mode

Source: Debaillie, Desset, Louagie, A Flexible and Future-Proof Power Model for Cellular Base Stations,In Proc. IEEE Vehicular Tech. Conf. Spring 2015, Glasgow, Scotland, May 2015.

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NR: Ultra-lean Design Example

5 0 10 ms

20 ms0 40 ms

NRDuty Cycle >0.5% (depends on SCS)Transmission periodicity 20 ms

LTEDuty Cycle 50%Transmission periodicity 0.2 ms

System AccessUltra-lean Design

5G: up to 100x lower duty cycle, up to 100x longer sleep duration

0.2 ms

Tx

pow

erT

xpo

wer

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Comparison of LTE and NRIdle mode power consumption

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LTE Rel-8, 2008-2009• Optimized for full load.• “CRS all the time over all the bandwidth” identified as problem late in the Rel-8

specification process.• No models and methodology for evaluating NW energy consumption.• No agreement to change Rel-8 standard late in the specification process.• Not possible to fix in sub-sequent releases due to “backwards compatibility” concerns.

EARTH project, 2010-2012• Industry-wide accepted energy efficiency evaluation framework (E3F).• Recommendations for EE network design.• Ericsson technical coordinator and key contributor.

Why the 20 ms cake?

3GPP New Radio, 2016-2017• NW energy consumption established as “key

performance criterion for IMT 2020”.• Ericsson successfully pushing for long DTX in 5G

New Radio standard.• 20 ms is the maximum SSB periodicity for

NR stand-alone operation.

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› Increased range– High gain beamforming enables larger

inter-site distance

› Spatial multiplexing– Peak-hour capacity is dimensioning

– With MU-MIMO each user can get the full bandwidth

› Rush to sleep– High rate � more sleep

Massive MU-MIMO & Energy

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High gain BF � larger ISD � fewer sites � lower NW energy consumption

Coverage Gain � Energy Gain

Source: P. Frenger, M. Olsson, and E. Eriksson, “Radio Network Energy Performance of Massive MIMO Beamforming Systems,” in Proc. IEEE PIMRC 2014.

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Site energy consumption

~ 2018-2019:LTE and

time-to-market optimized NR

Early NR product consume more energy than mature LTE products- NR bandwidth significantly wider (up to 25 times more BW)- Many more radio chains (due to massive MIMO)

2019++:LTE and energy

optimized NR

Future:Stand-alone and

energy optimized NR

Today:LTE-only

NR utilizing “ultra lean design” possibilities (and more).Additional improvements with each product release.

Site

ene

rgy

cons

umpt

ion

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Key Takeaways

› Design principles for 5G energy performance:– Only be active and transmit when needed– Only be active and transmit where needed

› Key technical enablers for enhanced network energy performance in 5G

– Ultra-lean design: Longer DTX (and more)– High Gain Massive MIMO Beamforming: Increased ISD

› Focusing only on NR is not enough– Due to ultra-lean design and higher capacity

NR will add less energy than previous generations did– Reducing NW energy consumption requires addressing

existing LTE, WCDMA, and GSM deployments

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