5G Network Energy performance Dr. Pål Frenger, Ericsson Research, 2017-11-14 Energy Performance Public Ericsson AB 2017 2017-11-23 Page 1
Network energy performance Minimizing total network energy consumption, despite increased traffic and service expansion Economy Ecology Engineering Energy Energy Performance Ericsson Public AB 2017 Ericsson Public AB 2017-11-23 2017-11-23 Page 2
The big picture Core / IP RAN 4G 3G ~20% ~80% 1G 2G Dominating parts: RAN: macro base stations Macro base stations: radio power amplifier Energy Performance Public Ericsson AB 2017 2017-11-23 Page 3
What will happen with 5G? 2G 3G 4G 5G Business As Usual Or can we do better? Energy Energy Performance Ericsson Public AB 2017 Ericsson Public AB 2017-11-23 2017-11-23 Page 4
NR Energy Performance Load adaptive energy consumption Only transmit when and where needed Energy Energy Performance Ericsson Public AB 2017 Ericsson Public AB 2017-11-23 2017-11-23 Page 5
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 Active Active Ericsson Energy Performance AB 2017 Public Ericsson AB 2017 2017-11-23 Page 6
LTE Traffic vs energy consumption Networks dimensioned for peak traffic demand Low average resource utilization Considerable static energy consumption in networks 50% 40% 30% 20% 10% 0% Network Traffic Load Normal traffic Very high traffic Extreme traffic Network Energy Consumption Improve load dependence! Normal traffic Very high traffic Extreme traffic Energy Energy Performance Ericsson Public AB 2017 Ericsson Public AB 2017-11-23 2017-11-23 Page 7
Micro sleep TX Cell DTX RBS power usage Full load Empty LTE radio Frame Ref. Symbols, Sync, Sys Info Active Frequency (6 PRB) RF output power Time (10 ms) Energy Performance Public Ericsson AB 2017 2017-11-23 Page 8
Micro sleep TX Cell DTX RBS power usage Full load Ref. Symbols, Sync, Sys Info Active Sleep mode RF output power 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. Energy Performance Public Ericsson AB 2017 2017-11-23 Page 9
NR: Ultra-lean Design Example System Access Ultra-lean Design Tx power NR Duty Cycle >0.5% (depends on SCS) Transmission periodicity 20 ms 0 20 ms 40 ms 0.2 ms Tx power LTE Duty Cycle 50% Transmission periodicity 0.2 ms Energy Performance Public Ericsson AB 2017 2017-11-23 Page 10 0 5 10 ms 5G: up to 100x lower duty cycle, up to 100x longer sleep duration
Comparison of LTE and NR Idle mode power consumption Energy Performance Public Ericsson AB 2017 2017-11-23 Page 11
Why the 20 ms cake? 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. Energy Performance Public Ericsson AB 2017 2017-11-23 Page 12 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.
Massive MU-MIMO & Energy 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 Energy Performance Public Ericsson AB 2017 2017-11-23 Page 13
Coverage Gain Energy Gain High gain BF larger ISD fewer sites lower NW energy consumption Energy Performance Public Ericsson AB 2017 2017-11-23 Page 14 Source: P. Frenger, M. Olsson, and E. Eriksson, Radio Network Energy Performance of Massive MIMO Beamforming Systems, in Proc. IEEE PIMRC 2014.
Site energy consumption Site energy consumption Today: LTE-only ~ 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) NR utilizing ultra lean design possibilities (and more). Additional improvements with each product release. 2019++: LTE and energy optimized NR Future: Stand-alone and energy optimized NR Energy Energy Performance Ericsson Public AB 2017 Ericsson Public AB 2017-11-23 2017-11-23 Page 15
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 Energy Performance Public Ericsson AB 2017 2017-11-23 Page 16
Energy Performance Public Ericsson AB 2017 2017-11-23 Page 17