Dept. of Electrical Engineering, Communication Systems Slide 1

Lower Layer Enablers for Agile and Efficient Dense Wireless Networks

Towards 6G

Tommy SvenssonFull Professor, PhD, Leader Wireless Systems

Department of Electrical Engineering, Communication Systems Group

Chalmers University of Technology, SWEDEN

tommy.svensson@chalmers.se

6G Channel: 6G Research Visions Webinar SeriesScoring the Terabit/s Goal: Broadband Connectivity in 6GNov 4, 2020

Dept. of Electrical Engineering, Communication Systems Slide 2

• 4G: Internet -> Mobile Internet ->

5G and Beyond: A New Era Has Begun

• 5G: Rich mobile Internet, Wireless Internet of Things

Robustness, Low latency => Internet of SkillsSource: https://www.aeteurope.com/news/technologies-

secure-internet-things/

Source: https://www.ericsson.com/thinkingahead/the-networked-

society-blog/2017/02/14/virtual-reality-comes-age-internet-skills/

Still work to be done:”Beyond 5G”

• Convergence of computing, communications, storage and Artificial Intelligence=> Massive and Distributed (i.e. local) Internet of Skills

Source: https://towardsdatascience.com/ai-the-future-of-technology-and-the-world-86f59d0cf720

6G?

What about 6G?

Need for holistic research based on holistic performance metrics• e2e latency, e2e security, total energy efficiency, sustainability, …

Dept. of Electrical Engineering, Communication Systems Slide 3

Broadband Connectivity in 6G

• N. Rajatheva, I. Atzeni, E. Björnson, A. Bourdoux, S. Buzzi, J. B. Doré, S. Erkucuk, M. Fuentes, K. Guan, Y. Hu, X. Huang, J. Hulkkonen, J. M. Jornet, M. Katz, R. Nilsson, E. Panayirci, K. Rabie, N. Rajapaksha, M. J. Salehi, H. Sarieddeen, S. Shahabuddin, T. Svensson, O. Tervo, A. Tölli, Q. Wu, W. Xu, “White paper on broadband connectivity in 6G”, June 2020. Online: https://www.6gchannel.com/portfolio-posts/6g-white-paper-broadband-connectivity-6g/

• N. Rajatheva, I. Atzeni, S. Bicais, E. Björnson, A. Bourdoux, S. Buzzi, C. D’Andrea, J. B. Dore’, S. Erkucuk, M. Fuentes, K. Guan, Y. Hu, X. Huang, J. Hulkkonen, J. M. Jornet, M. Katz, B. Makki, R. Nilsson, E. Panayirci, K. Rabie, N. Rajapaksha, M. J. Salehi, H. Sarieddeen, S. Shahabuddin, T. Svensson, O. Tervo, A. Tölli, Q. Wu, W. Xu , “Scoring the Terabit/s Goal: Broadband Connectivity in 6G”, Submitted to IEEE Communications Surveys and Tutorials (COMST). https://arxiv.org/pdf/2008.07220.pdf

© 6G FlagshipNote:• Not all KPIs will need to be supported simultaneously in a given use case.• However, many applications will need a certain combination of KPI values.• To meet overall metrics such as Total energy consumption, security and

sustainability, we should target to just meet service related KPIs, not over-do to!• It is very likely that 6G will to a large extent carry information related also to

non-traditional applications of wireless communications, such as distributed caching, computing, and AI decisions.

• Thus, there might be a need to introduce new KPIs for such applications, if the traditional KPIs are not sufficient.

Key Performance Indicators (KPIs)

Dept. of Electrical Engineering, Communication Systems Slide 4

Illustration of Sufficient KPI Optimization:Energy Minimization under Service Constraints in mm-wave Multi-node Cooperation

• Multiple base stations (BSs) jointly serving users to mitigate blocking and load balancing in dense mm-wave networks (standalone mm-wave BSs/ non-standalone, macro-BS assisted)

• Derive (close to) optimal fully digital- (FDB) and hybrid beamforming (HB) schemes.

• Minimize sum power subject to per-user spectral efficiency constraints and per BS peak power constraints, considering both hardware and RF transmit power of sleep mode capable BSs.

Jointly optimize

• Precoding

• Load balancing

• BS operation mode

To minimize network

energy efficiency.

• C. Fang, B. Makki, J. Li, T. Svensson, “Coordinated Hybrid Precoding for Energy-efficient Millimeter Wave Systems”, SPAWC’2018. Invited paper.

• C. Fang, B. Makki, J. Li, T. Svensson, “Hybrid Precoding in Cooperative Millimeter Wave Networks”, Under minor revision IEEE TWC. arXiv: https://arxiv.org/abs/2001.04390.

Sum RF transmit power and sum total power of all BSs BS activation probability vs number of cooperative BSs

Dept. of Electrical Engineering, Communication Systems Slide 5

Source: mmMAGIC

Agile Converged Access/ Backhaul/ Fronthaul withNetwork Slicing Awareness

CoMP -> Distributed Large MIMO (cell-free)

Vertical Convergence

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Group Cell 1

Group Cell 2

Group Cell 3

Integrated Mobility Support

X. Xu, X. Tao, C. Wu and P. Zhang, "Capacity and Coverage Analyses for the Generalized Distributed Cellular Architecture-Group Cell," 2006 International Conference on Communications, Circuits and Systems, Guilin, 2006, pp. 847-851.

Integrated Access and Backhaul (IAB)

C. Madapatha, B. Makki, C. Fang, O. Teyeb, E. Dahlman, M. S. Alouini, T. Svensson, “On Integrated Access and Backhaul Networks: Current Status and Potentials”, IEEE Open Journal of the Communications Society (OJ-COMS), vol. 1, pp. 1374-1389, 2020. arXiv: https://arxiv.org/abs/2006.14216

Joint mm-wave/sub-THz ─ FSO/ OWC

B. Makki, T. Svensson, M. Brandt-Pearce, M.S. Alouini, “On the Performance of Millimeter Wave-based RF-FSO Multi-hop and Mesh Networks”, IEEE Transactions on Wireless Communications, vol. 16, no. 12, pp. 7746-7759, Dec. 2017.

ReconfigurableIntelligent Surfaces (RIS)

S. M. Razavizadeh, T. Svensson, “3D Beamforming in Intelligent Reconfigurable Surface-assisted Wireless Communication Networks”, WSA’2020.

Key 6G Technical Enablers

D=20 m

LT=10 m

LR=10 m

scenario 1: communicating buildings,

N=512, f=30.72GHz

D=45m

LT=LR=9m

scenario 2: communicating lamp posts

(these are heights and separations in

France), N=256, f=42.7GHz

D=50 cm

LT=25 cm

LR=25 cm

scenario 3: communicating

laptops, N=32, f=76.8GHz

D=0.5 m

LT=1 m

LR=1 m

scenario 4: side-to-side

communicating cars (non

moving), N=256, f=38.4GHz

D=10 cmLT=50 cm

LR=50 cm

scenario 5: communicating laptop-

screen, N=512, f=61.4GHz

Legend:

Uniform linear

antenna array

Massive MIMO at Both Tx, Rx (MMIMMO)

D.-T. Phan-Huy, P. Ratajczak, R. D'Errico, A. Clemente, J. Järveläinen, D. Kong, K. Haneda, B. Bulut, A. Karttunen, M. Beach, E. Mellios, M. Castaneda, M. Hunukumbure, T. Svensson, ”Massive Multiple Input Massive Multiple Output for 5G Wireless Backhauling”, IEEE Globecom’2017 ET5GB workshop.

N. Rajatheva, I. Atzeni, S. Bicais, E. Björnson, A. Bourdoux, S. Buzzi, C. D’Andrea, J. B. Dore’, S. Erkucuk, M. Fuentes, K. Guan, Y. Hu, X. Huang, J. Hulkkonen, J. M. Jornet, M. Katz, B. Makki, R. Nilsson, E. Panayirci, K. Rabie, N. Rajapaksha, M. J. Salehi, H. Sarieddeen, S. Shahabuddin, T. Svensson, O. Tervo, A. Tölli, Q. Wu, W. Xu , “Scoring the Terabit/s Goal: Broadband Connectivityin 6G”, Submitted to IEEE Communications Surveys and Tutorials (COMST). arXiv: https://arxiv.org/pdf/2008.07220.pdf

N. Rajatheva, I. Atzeni, S. Bicais, E. Björnson, A. Bourdoux, S. Buzzi, C. D’Andrea, J. B. Dore’, S. Erkucuk, M. Fuentes, K. Guan, Y. Hu, X. Huang, J. Hulkkonen, J. M. Jornet, M. Katz, B. Makki, R. Nilsson, E. Panayirci, K. Rabie, N. Rajapaksha, M. J. Salehi, H. Sarieddeen, S. Shahabuddin, T. Svensson, O. Tervo, A. Tölli, Q. Wu, W. Xu , “Scoring the Terabit/s Goal: Broadband Connectivity in 6G”, Submitted to IEEE Communications Surveys and Tutorials (COMST). arXiv: https://arxiv.org/pdf/2008.07220.pdf

Dept. of Electrical Engineering, Communication Systems Slide 6

Integrated Access and Backhaul (IAB)

C. Madapatha, B. Makki, C. Fang, O. Teyeb, E. Dahlman, M. S. Alouini, T. Svensson, “On Integrated Access and Backhaul Networks: Current Status and Potentials”, IEEE Open Journal of the Communications Society (OJ-COMS), vol. 1, pp. 1374-1389, 2020. arXiv: https://arxiv.org/abs/2006.14216

Arguments for IAB

• Network resources flexibility

• Network cost reduction

• Time-to-market reduction

• Controlled interference also in the backhaul/fronthaul

• Simulation parameters: (αLOS ; αNLOS = (2; 3), blocker lengths lB = 5 m, fc = 28 GHz, bandwidth= 1 GHz and PMBS; PSBS; PUE = (40; 24; 0) dBm.

• Simulation parameters: (αLOS ; αNLOS) = (2; 3), blocker lengths lB = 5 m, fc = 28 GHz, bandwidth= 1 GHz and PMBS; PSBS; PUE = (40; 24; 0) dBm.

System modelNode/BS Distribution Finite homogeneous poisson point processes (FHPPP) for macro BS density

(λM), small BS density (λS), blockers (λB) and users (λU). Two-tier HetNet on a circular plane

Blocking model Germ grain model OpenStreetMap 3D

Rain model: ITU-R Rec 8.38-3

IAB nodes density providing same coverage probability as fiber-backhauling Service coverage probability as a function of percentage of fiber-backhauled SBSs

Dept. of Electrical Engineering, Communication Systems Slide 7

SEMANTIC: End-to-end (E2E) Network Slicing

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A1: Spectrum and System Coexistence Aspects for 5G NR operation in multi-GHz bands

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C: End-to-end slicing and optimizations for the next generation cellular network

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C1: Integrated access and backhaul techniques for NR communications

D3: Inter-slice management and network-wide resource orchestration

D1: Programmability and automation for the 5G NR

Network Analytics

A2: 5G NR forward-compatible design and future-proof enhancements

B1: MEC service mobility and continuity

B2: Enriched MEC services for flexible resource utilization and

massive connectivity

C2: End-to-end network slicing and traffic steering for next generation cellular networks

D2: Automated network service placement and functional chaining over joint cellular/MEC infrastructures

https://semantic2020.eu/

6G Technical enablers:• Heterogenous spectrum• Massive connectivity, path

diversity and control (split user/ control plane)

=> Phy/MAC network slicingenablers might be an importanttool for E2E network slicing• Agile multi-connectivity• Agile duplexing schemes• Agile non-orthogonal

(massive) MIMO 3D channelization

• Adaptive numerology and agile waveforms

• …

• MULTI-GHZ SPECTRUM communications,• MEC-EMPOWERED service provisioning,• END-TO-END NETWORK SLICING,• All integrated and jointly orchestrated by forward-looking DATA-DRIVEN NETWORK CONTROL AND AUTOMATION, • Exploiting the enormous amounts of mobile BIG DATA spurred into the MOBILE DATA NETWORK.

Dept. of Electrical Engineering, Communication Systems Slide 8

THz the Broader Scope: THz Flagship (2018)

Material and Process Technology

Components and Device

Subsystem and System

THz Value Chain Application Areas

Future Connectivity

Radar and Sensing for Mobility

Manufacturing and Robotics

Security

Health

Space Exploration and Climate Change

Food and Agriculture

Open Science Track

Mission: To catalyse the revolution of THz science and technology (S&T) and transform

business of all the industries in the THz value chain in the next 10 years.

https://teraflag.eu/

Supported by 176 organizations in Europe:

Universities (67), RTOs (33), SMEs (41), Large Industries (20), Space Agencies (5),

National/European Initiatives/Association (9), Innovation Management (1) Slide 8

Dept. of Electrical Engineering, Communication Systems Slide 9

EU FP4FRAMES → WCDMA

EU FP6WINNER, WINNER II →

LTE

EUREKA CELTICWINNER+ → LTE-Advanced

EU FP7ARTIST4G → LTE-Adv. evolution

https://5g-ppp.eu/5gcarhttps://5g-mmmagic.euhttps://www.metis2020.euhttps://ict-artist4g.euhttp://projects.celtic-initiative.org/winner+ http://cordis.europa.eu/infowin/acts/rus/projects/ac090.htm

Communications Systems group at Chalmers University of TechnologyImpacts Wireless Standards: 3G, 4G, 5G, and counting...

3G

3.9G

4G

CelticExcellenceAward in

Gold

EU FP7METIS→ Draft 5G

4G evolution

5G

Horizon20205GPPP mmMAGIC →5G

5G verticals

Horizon20205GPPP 5GCar →5G refinements

Cellular

V2Xfor Connected

Automated

Driving

Wiley, 2020

To appear

6G: Upcoming, stay tuned!