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6G: Towards a Fully Digital and Connected World - 6G Wireless Summit
6G: Towards a Fully Digital and Connected World
Marco Giordani◦, Michele Polese◦, Marco Mezzavilla†, Sundeep Rangan†, Michele Zorzi◦
                   ◦University of Padova, Department of Information Engineering, Italy
          † NYU WIRELESS, Tandon School of Engineering, New York University, Brooklyn, NY, USA

                          6G Wireless Summit, Levi, Finland
                                 March 26th, 2019
6G: Towards a Fully Digital and Connected World - 6G Wireless Summit
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                                                       Outline

Ø Introduction and Motivations

Ø 6G Key Performance Indices (KPIs)

Ø 6G Potential Applications
Ø 6G Enabling Technologies
 •      Disruptive Communication Technologies
 •      Novel 6G Communication Enabler
 •      Innovative Network Architectures
 •      Integrating Intelligence in the Network

Ø Conclusions and Research Directions

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                                       Introduction and Motivations

        •       From 1G to 5G, passing through UMTS and LTE innovations, each generation of mobile
                technology has tried to meet the needs of network operators and final consumers
        •       The rapid development of data-centric and automated processes may exceed even the
                capabilities of emerging 5G systems, thereby calling for a new wireless generation
innovation

                                                                                                            6G
                                                                                   1-10 Gbps

                                                                                      5G
                                                               100-1000 Mbps

                                                  2 Mbps
                                                                   4G
                                  64 Kbps
                  2.4 Kbps                          3G
                     1G              2G

                                                                Internet of    Massive broadband
              Voice calling         SMS          Internet      Applications     Internet of Things         Towards a Fully Digital and Connected World
                   1980             1990          2000            2010               2020      2025-2030                                                     time

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                              Introduction and Motivations

5G is always associated with trade-offs: 6G will contribute to fill the gap between beyond-2020
        societal and business demands and what 5G (and its predecessors) can support

•   Consider potential applications for future connected systems and estimate the key
    requirements in terms of throughput, latency, connectivity and other factors.
•   Identify use cases beyond the performance of 5G systems under development today.

•   Survey emerging technologies that are not available in networks today but have significant
    promise for future 6G systems (including developments at all layers of the protocol stack)

                                                          New Spectrum          Disaggregation/ virtualization

                                                      Disruptive Technologies         Energy Efficiency

                                                        Cell-less Networks          Artificial Intelligence

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6G: Towards a Fully Digital and Connected World
                 6G Applications and Use Cases

                                        6G Wireless Summit, Levi, Finland
                                               March 26th, 2019

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                                                      6G Use Cases

  Massive Scale
 Communication                                                  Virtual Reality                 E-Health

                                                        High-Speed Mobility

                                                                                        Industry 4.0
                  Tactile Internet

Smart Cities

                                                      Holographic Telepresence    Autonomous Driving

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                           6G Applications and Use Cases

                                                      INDOOR COVERAGE

•    80% of the mobile traffic is generated indoor
•    5G current cellular networks never really targeted indoor coverage
        Ø High-frequencies cannot penetrate solid material
        Ø 5G densification through femtocells (proposed as a solution) presents scalability
          issues and high deployment and management costs for operators

                                                            6G

        6G should target cost-aware indoor connectivity
        solutions autonomously deployed by end-users
            and managed by the network operators
               (e.g., wireless relays coupled with
                     indoor communications)

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                            6G Applications and Use Cases

                                                       MASSIVE SCALE COMMUNICATIONS

•   5G networks are designed to support more than 1’000’000 connections per km2
•   Mobile traffic will grow 3-fold from 2016 to 2021, pushing the number of connected devices to
    the extreme (> 500 billion connected things worldwide by 2030)
•   This will stress already congested networks, which will not guarantee the required QoS

                                                                    6G

                6G targets capacity expansion to offer high
                 throughput and continuous connectivity,
                      even when civil communication
                   infrastructures may be compromised
                    (public safety is main requirement)

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                            6G Applications and Use Cases

                                                       eHEALTH

•   OBJECTIVE: revolutionize the health-care sector, e.g., eliminating time and space barriers
    through remote surgery and guaranteeing health-care workflow optimizations.
•   Current communication technologies cannot be applied in future health-care
      Ø high cost and lack of real-time tactile feedback
      Ø mmWaves can support low-latency, but do not guarantee connection continuity.

                                                          6G

               6G enhancements will unleash the potential
               of eHealth applications through innovations
                like mobile edge computing, virtualization
                        and artificial intelligence

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                            6G Applications and Use Cases

                                                       INDUSTRY 4.0 and ROBOTICS

•   OBJECTIVE: digital transformation of manufacturing through Cyber Physical Systems (CPS)
    and Internet of Things (IoT) services.

•   Enabling, among other things, Internet-based diagnostics, maintenance, operation, and direct
    Machine to Machine (M2M) communications in a cost-effective, flexible and efficient way.

•   CPS will break the boundaries between the physical factory and the cyber space computation.

                                                                 6G

             6G will foster the Industry 4.0 revolution
               through new semiconductor and IC
                innovations (e.g., terahertz scale
                 electronic packaging solutions)

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                           6G Applications and Use Cases

                                                      SMART CITY

•   OBJECTIVE: life quality improvements, environmental monitoring, traffic control and city
    management automation
•   Current cellular systems have been mainly developed for broadband applications

•   Smart city applications build upon data generated by low-cost and low-energy consuming
    sensors, which efficiently interact with each other.

                                                          6G

             6G will seamlessly include support for user-
               centric M2M communication, promoting
                ultra-long battery lifetime combined
                 with energy harvesting approaches

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                           6G Applications and Use Cases

                                                      HOLOGRAPHIC TELEPRESENCE

•   OBJECTIVE: remotely connect with an increasing amount of digital accuracy
•   ISSUE: raw hologram, without any optimization nor compression, with colors, full parallax,
    and 30 fps, would require a daunting 4.32 Tbps data rate.

•   ISSUE: latency requirement will hit the sub-millisecond, and thousands of synchronized view
    angles will be necessary (2 tiles for 4K/8K HD, and 12 tiles for VR/AR)

                                                                 6G

             6G will develop architectures and network
            designs able to digitalize and transfer all the
                  5 human senses, increasing the
                       overall target data rate

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                            6G Applications and Use Cases

                                         UNMANNED MOBILITY (Autonomous Driving)

•   OBJECTIVE: fully autonomous connected and intelligent transportation systems, offering safer
    traveling, improved traffic management, and support for infotainment applications (>7000B$)
•   Unprecedented levels of communication reliability and low end-to-end latency, even in
    ultra-high mobility scenarios (up to an impressive 1000 km/h).
•   Sensors (more than 200 per vehicle by 2020) will demand increasing data rates (in the order
    of terabytes per driving hour), saturating the capacity of traditional technologies.

                                                            6G
             6G will pave the way for the coming era of
             connected vehicles through hardware and
                   software advancements and new
                 technologies to eliminate typical 5G
              latency/reliability/throughput trade offs

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6G: Towards a Fully Digital and Connected World
                6G Technologies and Innovations

                                        6G Wireless Summit, Levi, Finland
                                               March 26th, 2019

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 creasing energy and
  Increasing energy and
     bandwidth
                                                         6G Technologies and Innovations
        bandwidth

ncreasing wavelength                                          Disruptive Communication Technologies – Terahertz
  Increasing wavelength

                                                      TeraHertz                                                                       Visible Light
      •         Frequency bands   between 100 GHz and 1 THz
                           TeraHertz                         à bring
                                                          Visible Light to the extreme the potentials and
                                              430 THz                      770 THz
                challenges of high-frequency communications.
                 300 GHz            10 THz
                                                  430 THz                      770 THz
GHz                                 300 GHz                              10 THz

      •         Huge data rates (possible to allocate contiguous chunks of up to 200 GHz of spectrum)

 0 dB    0 dB                                         Pathloss [dB]       150 dB                        Received
                                                                                       00 W0.002 0.004 0.006         Power
                                                                                                             0.008 0.01 0.012 [W]             0.020.02W
                                                                                                                               0.014 0.016 0.018
   150 dB    0 dB                                        Pathloss [dB]        150 dB                         Received
                                                                                            00 W0.002 0.004 0.006         Power
                                                                                                                  0.008 0.01  0.012 [W]             0.020.02W
                                                                                                                                     0.014 0.016 0.018
                                                                                                                                  PROPAGATION LOSS (compensated using directional
                                                                                                                                  antenna arrays, also enabling spatial multiplexing
                                                                                                                                          LED1
                                                                                                                                  without increasing the interference)
                                                                                       Received Power [W]

                            102                                                                                                                    LEDLED
                                                                                                                                                       1 2
                                                                                                            Received Power [W]

                                         102                                                                                                              LED2
           Distance [m]
                          Distance [m]

                           10-2
                                         10-2
                                                                                                                                      MOLECULAR ABSORPTION (it is important to choose
                                                                                                                                      deployments in frequency bands not severely affected
                                                                                                                       8
                                                                                                                                      by molecular absorption)
                                                                                                                                                             8
                                                                                                                                 86                              6
                           10-5                                                                                                       4                                     8
                                                                                                                                      6                     4
00                                        0.1                 5              10                                                           42          2              6
                                         10-5                                                                                                                    4
     300                                        0.1              5
                                                       Frequency [THz]            10                         Y Room [m]                        2          2X Room [m]
                                                           Frequency [THz]                                       Y Room [m]                                    X Room [m]

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                                                                 6G Technologies and Innovations

                                              Disruptive Communication Technologies – Visible Light Communications

        •    Frequency bands between 430 GHz and 770 THz à complement RF communications by
                        Visible
             piggybacking
                     Visibleon  Lightwide adoption of LED luminaries
                                the
                             Light
            430430
                THzTHz                                                                     770 770
                                                                                               THzTHz
        •    VLC devices can switch between different light intensities to modulate a signal

        •    More mature research than THz (standard for VLC – IEEE 802.15.7 – has been defined)

B0 dB            00 W0.002
             00 W0.002 0.004 0.004    Received
                                     0.006
                                       0.008 0.008
                                Received
                               0.006              Power
                                                0.01   Power
                                                     0.01
                                                      0.012   0.014[W]
                                                            0.012
                                                            [W]     0.014
                                                                      0.016 0.016      0.02
                                                                                    0.018
                                                                                 0.02
                                                                              0.018       W 0.02W
                                                                                       0.02
                                                                                                                 INTERFERENCE (limited coverage range, require an
                                                                                                                 illumination source and suffer from shot noise from
                                                                         LEDLED
                                                                            1   1                                other light sources)
                                  Received Power [W]
             Received Power [W]

                                                                               LEDLED
                                                                                  2   2

                                                                                                                     MULTI-CONNECTIVITY: need to be
                                                                                                                     complemented by RF for the uplink
                                                 8     8
                                                        6   6                                      8   8
                                                             4   4                         6   6
10                                                                        2            4 4
                                                                     2          2   2
                                          Y Room
                                       Y Room [m] [m]                                   X Room
                                                                                     X Room [m] [m]

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•
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        systems

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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           The transceiver in base stations and UEs will be capable of TX a signal while also TX

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                                                                                                                                                                                                                                                                                                                                                                       Enhancements

                                            The sub-6 GHz channel is H and the mmWave channel is H.
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                IEEE

                                                                                                                                                                                                                                                                       Boyd, and

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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            M. L. geometries

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                                                                                                                        Transmitter Receiver
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  Bencheikh, Y. Wang,

             17
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    no.Trans.
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       III. S YSTEM AND CHANNEL MODEL

                                                                                                                                                                                                                                                                                                                                                                                                                                                        [57]technology–Telecommunications

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                                                                                                                                                                                                                                                                                RF Chain
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                                                                                                                                               http://www.stanford.edu/ boyd/cvx http://www.stanford.edu/ boyd/cvx
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       Gaussian or truncated Laplacian), and the complex coefficients ↵r

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   with

                                                                                                                                                                                                                                                                                                                                                                                                                                                              “IEEE standard for informationand

                                                                                                                                                                                                                                                                                   disciplined
                                                                                                                                                                                                                                                                                                                                                                            area networks–Specific
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          side
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   or control messages à

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        3, pp.Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  c,i

                                                                                                                                                                                                                                                                                                                                                                                           amendment

                                                                                                                                                                                                                                                                                     Ye, “CVX:

                                                                                                                                                                                                                                                                                DAC
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                                                                                                                                                                                                                                                                                               convex
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  limited data

                                                                                                                                                                                                                                                                                                 Matlab

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                                                                                                                                                                                                                                                                                                                                                                                               high throughput
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      and H.suitable

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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   information exchange
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        mod  roo

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           [53] R. Keys, “Cubic convolution interpolation for digital ima
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         and hav

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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              We consider a multi-band MIMO system shown in Fig. 1, where ULAs of is
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                            6G Technologies and Innovations

                           Disruptive Communication Technologies – Channel Sparsity

 • Estimating the mmWave channel is equivalent to estimating the parameters of the channel
   paths, i.e., the AoA, the AoD, and the gain of each path.
 • IDEA: exploit the poor scattering nature of the mmWave channel to formulate the mmWave
   channel estimation problem as a sparse compressed sensing problem: the channel power is
   concentrated in a few entries of a virtual channel matrix
 • It is sufficient to estimate the AoAs and AoDs
   of the dominant paths to be resolved.

            Example of 6 dominant paths (the location of each
           square reflects the AoA and time delay of each path)

                                                                                                                           (a) Grayscale of angular-delay domain
B. Wang, et al., "Spatial- and Frequency-Wideband Effects in Millimeter-Wave Massive MIMO Systems," in IEEE Trans. Sig. Proc., vol. 66, no. 13, pp. 3393-3406, Jul. 2018.
                                                                                                      Fig. 4. An illustration of a 6-path SFW channel, where M = 128, N = 12

        6G: Towards a Fully Digital and Connected World
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        6G Wireless Summit, 26th March 2019
                                                                                                      D. Sparse Channel Representation and Angular-Delay Or-
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                          6G Technologies and Innovations

                  Innovative Network Architectures – Disaggregation/virtualization

 • IDEA: decouple network/control plane (CP) and forwarding/user plane (UP).
   Ø SDN offers network programmability and centralization of the control
   Ø SDN is agile and responsive (traffic flow meets fluctuating needs and demands).
   Ø SDN is standards-based (e.g., OpenFlow) and vendor-neutral.

 • IDEA: replace network services provided by dedicated hardware (e.g., network
   switches) with virtualized software.
   Ø NFV saves capital and operating expenses

                                       NFV and SDN are complementary technologies
                                          (SDN executes on an NFV infrastructure)

• C. J. Bernardos et al., "An architecture for software defined wireless networking," in IEEE Wireless Communications, vol. 21, no. 3, pp. 52-61, June 2014.
• R. Mijumbi, et al., "Network Function Virtualization: State-of-the-Art and Research Challenges," in IEEE COMST, vol. 18, no. 1, pp. 236-262, 2016

      6G: Towards a Fully Digital and Connected World
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      6G Wireless Summit, 26th March 2019
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                             6G Technologies and Innovations

                      Innovative Network Architectures – Access/Backhaul integration

 •       Massive 6G data rates technologies à
                                                                                                                                        IAB node stack
                                                                                                                                 Backhaul                Access
                                                                                                                                      PDCP                PDCP

         adequate growth of the backhaul capacity                                                                                      RLC
                                                                                                                                      MAC
                                                                                                                                                           RLC
                                                                                                                                                          MAC
                                                                                                                                       PHY                 PHY

                                                                                                                                             SCHED

                                                                                                             Donor gNB

 •       THz and VLC deployments will call for a massive                                                                   IAB node

         increase in the density of access points, which should                                                                                          IAB node

         be provided with backhaul connectivity to the core network à expensive

 •       IDEA: deploy a fraction of BSs with traditional fiber-like backhaul capabilities and the rest
         of the BSs connecting to the fiber infrastructures wirelessly.
 •       6G deployments will introduce new challenges and opportunities
     •       The networks will need higher autonomous configuration capabilities
     •       Out-of-band IAB can be realized to increase the overall network throughput.

• M. Polese, et al. , "End- to-End Simulation of Integrated Access and Backahul at mmWaves,” to appear on IEEE CAMAD, Sep. 2018.
• M. Polese, et al., "Distributed Path Selection Strategies for Integrated Access and Backhaul at mmWaves", to appear on IEEE GLOBECOM, Dec. 2018

         6G: Towards a Fully Digital and Connected World
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         6G Wireless Summit, 26th March 2019
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                        6G Technologies and Innovations

                                 Integrating Intelligence in the Network – Learning

•   BACKGROUND: the signal received at multiple BSs renders a defining signature for the user
    location and its interaction with the surrounding environment.
•   BACKGROUND: UEs typically move through predefined paths, and some movements are
    impossible due to the presence of obstacles, e.g., buildings, walls.
•   IDEA: account for previous access statistics and use machine learning tools to predict the
    network behaviors (e.g., by remembering/observing consequences of previous decisions).

                  SUPERVISED LEARNING
             The amount of data generated
             will be massive, thus labeling
              the data may be infeasible.                      UNSUPERVISED LEARNING
                                                             Does not need labeling, used to
                                                              autonomously build complex
                                                                network representations

    6G: Towards a Fully Digital and Connected World
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    6G Wireless Summit, 26th March 2019
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                          6G Technologies and Innovations
    Mission Planning

              Integrating Intelligence in the Network – Knowledge sharing and learning
   Reference Planner
                                      Fig. 4: Reference planners result: the desired path cut corners
    • 5G: At                          at thebandwidth
                high frequency, the massive   turn to minimize   path length
                                                          and spatial    degreesand ofgenerate
                                                                                        freedombetter
                                                                                                  are
   Behavioral Planner
                                      handling
       unlikely to be fully used by any one cellular operator. Spectrum can be shared, in
         time and in space, with several performance and energy benefits:
  Controllers
        §     Reducing deployment costs, if operators share bands and infrastructures
                                                               Candidate Strategy Generation
          §      Inter-operators access and interference coordination
      ACC            Lane         Merge
    Controller     Centering      Assist                                        Multiple candidate strategies
    • 6G: operators and users may also be interested in sharing learned
      representations
ed behavioral             of specific network Prediction
              planning framework               deployments
                                                         Engine and/or use cases
          §      Speed up the network configuration in new markets
                                                            Predicted surrounding
                                                           traffic scenarios
          §      Better adapt to new unexpected scenarios which    may emerge during network operations
RAL     P LANNING F RAMEWORK                                  Cost function-based Evaluation
 ction II, there are shortcomings of                                                        Fuel
                                                           Progress   Comfort   Safety    Consum
archical and parallel robot decision                                                       -ption
Due to real-time constraints, the mo-
 nsider the effects of imperfect vehi-
peration between cars. In this paper,                                  Best Strategy
behavioral      planning framework that
       6G: Towards a Fully Digital and Connected World    Fig. 5: The block diagram of Prediction- and Cost-function
s of the   hierarchical
       6G Wireless                  and2019parallel ar-
                   Summit, 26th March
                                                                                                              22
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                                                            6G Challenges
                                                                                                            •    Circuit design, high propagation loss
•      Integrate energy characteristics in protocols
                                                                                                            •    Limited coverage, need for RF uplink
        • Energy vs. high-deployment / MIMO                                                                                                    5
                                                                                                            •    Need for reliable frequency mapping

                              Efficient and low-power network operations
                                             Energy will be at the core of 6G protocols design

                                                                                                                                 Extreme multi-connectivity

                                                                                     s
                                         g

                                                                                      e
                                     stin

                                                                                                                                 Exploit THz, VLC, mmWave and

                                                                                   nod
                                                                                                                                 sub-6 GHz links
                                        ve

                                                                               wer
                                    har

                                                                               -po
                                rgy

                                                                            Low
                              Ene

                                        Disaggregated and virtualized RAN
                   The networking equipment will not require dedicated hardware

                                    Cloud                        Edge                                                          Cell-less architecture
                                                                                                                               The UE connects to the RAN
                                                                                                                               and not to a single cell
                                              Virtual        Virtual
                                               MAC            PHY
                                               Generic hardware

                                                                Fig. 4: Architectural innovations introduced in 6G networks.

•     Slower network operations/security concerns                                                      • Scheduling, need for new network design
       • CU/UP    functions
               ping            arestudied
                    has been widely tightly  coupled
                                          [15], but such capabilities                                      Scalability,
                                                                                                    The• overcoming of the and   interference
                                                                                                                           cell concept            management
                                                                                                                                        will also enable
                        have never been deeply integrated with the operations and                   a tight integration of the different 6G communication
                        protocols of cellular networks. 6G networks will exploit                    technologies. The users will be able to seamlessly tran-
                        a unified interface for localization and communications                     sition among sub-6 GHz, mmWave, terahertz or VLC
                        to (i)and
    6G: Towards a Fully Digital improve  control
                                  Connected World operations, which can rely on                     links without manual interventions or configurations in
                                                                                                                                                                  23
    6G Wireless Summit,context
                         26th March 2019
                                 information  (without the need for exchanging                      the device, which will automatically select the best avail-
6G: Towards a Fully Digital and Connected World
Marco Giordani◦, Michele Polese◦, Marco Mezzavilla†, Sundeep Rangan†, Michele Zorzi◦
                   ◦University of Padova, Department of Information Engineering, Italy
          † NYU WIRELESS, Tandon School of Engineering, New York University, Brooklyn, NY, USA

                          6G Wireless Summit, Levi, Finland
                                 March 26th, 2019
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