Noname manuscript No.(will be inserted by the editor)

Wireless 5G Ultra Reliable Low LatencyCommunications

European and Austrian Research Initiatives.

Thomas Zemen

Received: date / Accepted: date

Abstract 5G standardization and research progresses at full speed on a world-wide scale. In this article we describe the architecture of future 5G systems,their use cases and key physical layer technologies. The time-plan and cur-rent state of 5G research in Europe in Horizon 2020 is presented. An overviewabout the research activities in Austria is given. Finally, the 5G research focusat AIT Austrian Insitute of Technology with its projects in the domain of ultrareliable low latency communications (URLLC) is introduced.

Keywords 5G · European research · Austrian research · ultra reliable lowlatency communications

1 Introduction

5G standardization and first system trials have created a wide interest in thenew system capabilities and use cases of 5G. 5G aims to increase the peakdata rate to 10Gbit/s, and focuses strongly on machine-to-machine (M2M)communication links where a latency (transmission delay from transmitter(TX) to receiver (RX)) of 1 ms and a battery lifetime of up to 10 years arekey performance parameters, see Fig. 1.

2 Three Systems in One

Clearly, a 5G system will not provide all the performance targets, shown inFig. 1, simultaneously for a single communication link. This is simply notpossible from the underlying physics. In fact, 5G provides a combination of

Thomas ZemenAIT Austrian Institute of Technology, Giefinggasse 4, 1210 Vienna, AustriaTel.: +43 664 88390738E-mail: thomas.zemen@ait.ac.at

2 Thomas ZemenStretching performance targets for 5G

19.06.2015

• Saving up to 90% of energy per service provided. • The dominating energy consumption comes from the

radio access network Dr. Werner Mohr, Chairman of 5GPPP

Nokia

Fig. 1 5G targets, c©Nokia.

three different, so called network slices, within one system [1]. These threeslices can be visualized as independent dimensions, see Fig. 2. Each dimension(network slice) targets a very different use case categorie [2]. These are:

– Enhanced mobile broad band (eMBB) for data rates up to 10 Gbit/s;– massive machine type communication (mMTC) with low energy consump-

tion for a battery life of 10 years, optimized for low data rates of 10 b/s;and

– ultra reliable low latency communication (URLLC) providing 1 ms latencyat low frame error rates.

The eMBB network slice is a straight forward extension of current LTEsystems to higher bandwidth of up to 10Gbit/s cell throughout. This data rateallows for ultra high definition video streaming, virtual or augmented realityapplications, as well as hot spot support with high user densities. Clearly, foreMBB the focus is on high data rates. Latency and power consumption areonly secondary parameters.

mMTC focuses on the internet of things (IoT) where long battery lifeis essential for practical operations, although data delivery does not requiretight deadlines or high data rates. mMTC allow the communication with alarge number of sensors, providing data such as temperature, position, etc.

URLLC is a key new wireless communication mode enabling wireless au-tomation and control applications. These are, e.g., networked autonomous ve-hicles, that need a wireless communication link for data exchange especiallyin rural environments like city centers, to achieve the safety level of currentroad traffic with human drivers. Another key application domain are Industry4.0 automation and control scenarios, to replace cables with wireless links forrobot-to-robot communication links or for collaborative human-robot produc-tion scenarios.

Wireless 5G Ultra Reliable Low Latency Communications 3

IEEE Communications Magazine • February 2014 145

M2M sensing devices, as well as 1 ms real-timelatency (Fig. 5) to meet requirements for tactilecontrol.

As all three dimensions may not need to beaddressed simultaneously for any class of service, itcan be assumed that it is feasible to design a new5G system that can meet these differing require-ments, and that it may differ greatly from 4G LTE:• Cellular communications with data rates of

10 Gb/s can enable ubiquitously availableimmersive virtual reality at levels not fore-seen.

• Context awareness and personalization builtinto all devices and services can transformthe way we communicate as humans.

• It is most likely that we will have variousaccess schemes to fulfill all our communica-tions needs. These schemes need to becomehighly integrated and coordinated to pro-vide a seamless experience to users andapplications.

• Communicating sensors embedded in ourenvironment can enable a host of new ser-vices. We can move from cellular/wirelessdata communications to a new level of wire-less monitoring.

• A round-trip latency of 1 ms can potentiallymove the world from enjoying today’s wire-less communication systems into the newworld of wireless control systems: the TactileInternet. It will dramatically change our life,impacting all aspects of application areas suchas health, safety, traffic, education, sports,games, and energy. For a first overview onapplication areas and challenges see [12].

* Discussions on setting the stage for LTEand beyond shows that a new physical layermay be needed, possibly parting fromOFDMA and embracing new concepts suchas generalized frequency-division multiplex-ing or filter bank multi-carrier [13].The result may be a revolutionary leap from

today’s wireless communications to personalizedcontext-based communications and future moni-toring and control networks. The future oppor-tunities in mobile communications are largerthan anyone can foresee. What we experiencetoday is only the very first glimpse. Obviously,with challenges as pointed out here, 5G cellularcommunication will be another paradigm shiftthat will redefine our future, impacting our soci-eties in ways that cannot be foreseen.

ACKNOWLEDGMENTSWe would like to acknowledge the contributionsof our teams at Vodafone Group R&D and TUDresden in shaping the vision, and we wouldalso like to thank the reviewers for their valuablecomments.

REFERENCES[1] Vodafone Institut, “Mobile Technologies — The Digital

Fabric of Our Lives,” www.vodafone-institut.de/uploads/media/Studies_komplett_FINAL_von_250913.pdf, Sept. 2013.

[2] G. P. Fettweis, “A 5G Wireless Communications Vision,”Microwave J., Dec. 14, 2012.

[3] C. Christensen, “The Innovator’s Dilemma,” Harper Busi-ness Essentials, 1997.

[4] J. Well, “Faster Than Fiber: The Future of Multi-Gb/s Wire-less,” IEEE Microwave Mag., May 2009, pp. 104–12.

[5] T. Rappaport et al., “Millimeter Wave Mobile Communi-cations for 5G Cellular: It Will Work!,” IEEE Access, vol.1, Digital Object Identifier 10.1109/ACCESS.2013.2260813, May 2013, pp. 335–49.

[6] S. Krone, “Wireless Communications with Coarse Quan-tization: Information-Theoretic Analysis and SystemDesign Aspects,” Vogt Verlag, 2012.

[7] M.A. Uusitalo, “Global Vision for the Future WirelessWorld from WWRF,” IEEE Vehic. Tech. Mag., vol. 1, no.2, 2006, pp. 4–8.

[8] J. Johnson, Designing With the Mind in Mind, MorganKaufman, 2010.

[9] E. Steinbach et al., “Haptic Communications,” Proc.IEEE, vol. 100, no. 4, Apr. 2012, pp. 937–56.

[10] M. T. G. Pain and A. Hibbs, “Sprint Starts and theMinimum Auditory Reaction Time,” J. Sports Sciences,vol. 25, no. 1, Jan. 2007, pp. 79–86.

[11] T. DeFanti and R. Stevens, “Teleimmersion,” Ch. 6, TheGrid: Blueprint for a New Computing Infrastructure,Elsevier Series in Grid Computing, pp 131–55.

[12] G. P. Fettweis, “The Tactile Internet — Applications &Challenges,” accepted for the IEE Vehic. Tech. Mag., toappear 2014.

[13] G. Wunder et al., “5GNOW: Non-Orthogonal Asyn-chronous Waveforms for Future Mobile Applications,”in this issue, IEEE Commun. Mag..

BIOGRAPHIESGERHARD P. FETTWEIS (Gerhard.Fettweis@vodafone-chair.com), born March 16, 1962, received his Ph.D. fromRWTH Aachen in 1990. Thereafter he joined IBM Researchand then TCSI, California. Since 1994 he is Vodafone ChairProfessor at TU Dresden, Germany. So far he has co-found-ed 11 startups. He runs the German Science Foundation’sCRC HAEC and COE cfAED. He helps organize IEEE confer-ences (e.g., TPC Chair ICC 2009 and TTM 2012, GeneralChair VTC Spring 2013 and DATE 2014).

SIAVASH ALAMOUTI, born March 16, 1962, received B.A.Sc.and M.A.Sc. degrees in electrical engineering from the Uni-versity of British Columbia. He is currently an entrepreneurhelping build new companies focused on personalization.He was the group R&D director for Vodafone from 2010 to2013. Before that he was an Intel Fellow and CTO of theMobile Wireless Group. Prior to joining Intel in 2004, heheld positions at various companies including Vivato,Cadence, and AT&T. He is most well known for the inven-tion of the Alamouti Code.

Figure 5. The wireless network moving from communications of content tomonitoring to control. The dashed lines indicate that applications allow for atrade-off between the three depicted criteria of optimization: speed, responsetime, and operation endurance.

Monitoring

Endurance:>10 years at 10 b/s and 1 Ah

ControlResponse: 1 ms

ContentSpeed: >10 Gb/s

FETTWEIS_LAYOUT.qxp_Layout 1/30/14 1:12 PM Page 145

Fig. 2 5G dimensions [1].

3 New Technologies

All of the above described new 5G features cannot be achieved by simplydownloading a new app on your current generation smart phone. Fundamentalchanges are needed to the physical wireless transmission layer technologiesto achieve the target parameters of Fig. 1. Three key new technologies haveemerged as primary candidates. These are [3]:

1. Massive multiple-input multiple output (MIMO) systems [4,5] using a largenumber of antennas (∼ 100) at the base station to allow for spectrallyefficient transmission;

2. the millimeter-wave frequency band from 30-90GHz is utilized to increasethe available bandwidth for high data rate wireless links [6]; and

3. network densification reduces the cell size and allows increased cell coop-eration [7,8].

All three technologies together shall increase the overall capacity of 5G systemsby a factor of 1000 compared to current 4G LTE systems.

4 5G Timeline - Research, Trials, Standards

An ambitious time-line is in place to progress from research over trials to astandard specification, see Fig. 3. The European commission is funding re-search projects in three phases via Horizon 2020 (H2020) in the 5G public pri-vate partnership (PPP). Phase two projects are currently ongoing and phasethree projects are about to start. In parallel, the 3GPP provides regular stan-dard releases, implementing first 5G features, enabling trials to be conducted

4 Thomas Zemen

5G PAN-EUROPEAN TRIALS ROADMAPMain Objectives

Support global EU leadership in 5G technology, 5G networks deployment and profitable 5G business.

Validate benefits of 5G to vertical sectors, public sector, businesses and consumers.

Initiate a clear path to successful and timely 5G deployment.

Expand commercial trials and demonstrations as well as national initiatives.

5G Pan-EU Trials Roadmap

DO YOU WANT TO PARTICIPATE?Visit: 5g-ppp.eu/5g-trials-roadmapContact us: TrialsRoadmap@5g-ppp.eu

Supported by the

Fig. 3 5G European timeplan, c©EC.

with standard like equipment. Release 15 will be published mid 2018 contain-ing the 5G new radio (NR) physical layer specification. Release 16 is expectedend of 2019. The world radio conference (WRC) will define the frequencybands for the 5G deployment in 2019.

5 European 5G-PPP Phase 2 Projects

The currently ongoing 5G-PPP phase research project in H2020 are focusingon 5 key aspects:

1. Wireless radio access network : The project ONE5G1 investigates end-to-end 5G new radio improvements, while SAT5G2 deals with the integrationof satellites into 5G. The URLLC connection in different scenarios mightvary quite significantly (vertical sectors). Hence, URLLC communicationlinks for vehicles is the focus of the project 5G CAR3 and URLLC forfactories-of-the-future (FoF) is taken care of in the project Clear5G.

2. Optical and wireless access network : Due to high bandwidth requirementsof 5G, an efficient optical access network is required. At the same timemmWave frequencies require new design methods for antenna arrays. Bothtopics together are tackled in the project BLUESPACE4 to obtain an opti-cal beamforming interface for mmWave transmission. Visible light commu-nication within buildings is the topic of the project IoRL5, and an optical

1 one5g.eu2 sat5g-project.eu3 5gcar.eu4 bluespace-5gppp.squarespace.com5 iorl.5g-ppp.eu

Wireless 5G Ultra Reliable Low Latency Communications 5

fronthaul architectures is investigates in 5G-PHOS6. Computing resourcesat the network edge, e.g. directly at the base station, are needed for low-latency operations. The combination of such edge computing with opti-cal networks is the topic of the project 5G-Pitcture7. Finally, the projectMETRO-HAUL8 investigates optical software defined networks (SDN) andnetwork function virtualization (NFV) within optical transport networks.

3. Networking and vertical industrial use cases: Broadcast and multicast for5G is taken care of in 5G-Xcast9, the project 5G-Transformer10 providesa mobile transport and computing platform for vertical industry sectors,while a communication infrastructure for the energy grid is designed in theproject NRG-511.

4. Network slicing and edge computing : A general slicing network shall bethe outcome of SLICENET12, solutions for 5G edge cloud computing andcommunication are provided by the project 5GCity13, and finally networkmanagement for 5G edge computing is investigated in 5G ESSENCE14.

5. SDN, NFV and services: Virtual network functions for 5G networks arethe topic of 5G-MEDIA15, 5G-MonNArch16 deals with mobile networkslicing using SDN and NFV, verification and validation of NFV is the scopeof the project 5G-Tango17. A 5G service framework is being developedin MATILDA18 and the goal of the project NGPaaS19 is a telco gradeplatform as a service.

6 Austrian 5G Research Landscape

With the project databases available at the Austrian Research PromotionAgency (FFG)20 and of the Christian Doppler Research Association21 thefollowing 5G related activities can be identified in Austria:

– TU Wien: Christian Doppler (CD) Lab for ”Dependable Wireless Connec-tivity for the Society in Motion”

6 www.5g-phos.eu7 www.5g-picture-project.eu8 metro-haul.eu9 5g-xcast.eu

10 5g-transformer.eu11 www.nrg5.eu12 slicenet.eu13 www.5gcity.eu14 www.5g-essence-h2020.eu15 www.5gmedia.eu16 5g-monarch.eu17 5gtango.eu18 www.matilda-5g.eu19 ngpaas.eu20 projekte.ffg.at21 cdg.ac.at

6 Thomas Zemen

– Salzburg Research: Network layer research for cyber physical systems (5G-Mlab, TriCePS)

– Johannes Kepler University Linz: CD-Lab Digitally Assisted RF Transceiversfor Future Mobile Communications

– Graz University of Technology: Dependable, secure and time-aware sensornetworks (DeSSnet)

– Uni Klagenfurt: 5G playground Carinthia

6.1 5G Research at the AIT Austrian Institute of Technology

At the AIT Austrian Institute of Technology a comprehensive 5G researchfocus has been established in recent years for URLLC applications as well asoptical wireless interfaces.

– Massive MIMO for Reliable 5G Vehicular Communications (MARCONI):Connected autonomous vehicles are able to exchange sensor information(radar, optical, etc.), kinematic information and maneuver information toachieve cooperative joint decisions in difficult traffic situations. This coop-eration helps to improve traffic safety and approach the goal of zero acci-dents. Highly-reliable and low-latency 5G wireless vehicle-to-infrastructure(V2I) communication links shall enable the cooperation in a controlledmanner, connecting vehicles to a mobile-edge cloud computing center atthe base-station location. The project MARCONI uses a massive multiple-input multiple-output (MIMO) systems where the base station is equippedwith 30...100 antenna elements while the mobile station uses a single an-tenna. With this setup, it is possible to focus the transmit energy of thebase station by coherent superposition at the location of the mobile sta-tion. New algorithms are explored to enable massive MIMO links for highlytime-variant and non-stationary V2I scenarios. To avoid shadowing, algo-rithms for distributed massive MIMO antennas are devised and transceiveralgorithms are implemented on a real-time software-defined radio (SDR)testbed.

– Fast Production Line Reconfiguration - Replacing Cables with Radio Com-munication Links (UNWIRE): The dynamic reconfigurability of currentproduction systems is severely hampered by the fixed wiring of automationand control systems. The exchange of cable connections with ultra-reliablewireless communication links, will improve the reconfigurability of futureproduction lines. Thus, the communication between sensors, actuators andprocessing units within a control cycle, needs to be supplemented by low-latency wireless communications. For fast control processes in productionsystems, a control cycle time of approx. 100µs is needed, which is notachievable with current wireless communication systems (state-of-the-artis 16 ms). Therefore, new low-latency wireless transmission methods arerequired for dynamically reconfigurable production systems that exploit alldiversity sources in industrial scenarios to achieve high transmission relia-bility. Based on a future production scenario analysis, the research within

Wireless 5G Ultra Reliable Low Latency Communications 7

UNWIRE aims for an industrial communication link with a cycle time of125µs. The frame error rate is minimized for industrial scenarios, throughoptimized wireless signal processing algorithms (in the transmitter and re-ceiver) and the dynamic selection of wireless relays with multiple antennas(network diversity). The key innovation of UNWIRE is to allow the dy-namic reconfiguration of production systems by the replacement of fixedwiring with radio links.

– Secure Connected Trustable Things (SCOTT): The project SCOTT focuseson wireless sensor and actuator networks and communication in the areasof mobility, building and smart infrastructure. This addresses numerousEuropean societal challenges such as smart, green and integrated trans-port, secure and inclusive societies as well as health and wellbeing. SCOTTwill enable efficient, trustworthy connectivity and facilitate ubiquity of in-telligent embedded systems and systems of systems, thus essentially con-tributing to burning issues in Automated Vehicles or Industry 4.0. AITis contributing to the measurement, modeling and real-time system levelsimulation of multi-node communication networks between vehicles on thestreet and on rails. On rails the communication link is used to realize avirtual coupling of high speed trains.

– Heterogeneous Integration of Millimeter-Wave Technology (TRITON): Mil-limeter-wave technology exploits unused frequency band starting from 30GHz opening new vistas for 5G communication scenarios. In the projectTRITON solutions for mm-wave technology along the entire functionalchain are developed: originating from high-frequency gallium-nitride-on-silicon-carbide (GaN-on-SiC) and silicon-germanium (SiGe) electronics ca-pable to operate energy efficiently at frequencies like the 30-GHz Ka-bandtowards silicon-on-insulator (SOI) photonics featuring low-drive modula-tors and photo detection for seamless translation of signals to and from theoptical domain. TRITON aims to fabricate and characterize test-chips, in-corporating the functionalities of millimeter-wave amplification in the 27-32 GHz range and translation to and from the optical domain in view ofemerging applications in 5G and the industrial internet.

7 Conclusions

Research, standardization and deployment of 5G is currently under way atfull pace using the targeted effort within Horizon 2020 in Europe. CurrentEuropean research projects investigate radio access, optical networks, networkslicing and edge computing, software defined networks, network function virtu-alization as well as service creation. Research activities in Austria are stronglyfocused on the Austrian industry needs, which are chip design, network oper-ation, and 5G for vertical ultra-reliable low-latency communication use cases.It is clear that the planned early 5G deployment will not stop research anddevelopment. New 5G features will be added with a regular release rhythmthroughout the next years to come.

8 Thomas Zemen

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