KEY DRIVERS AND RESEARCH CHALLENGES FOR 6G UBIQUITOUS WIRELESS INTELLIGENCE | 1 KEY DRIVERS AND RESEARCH CHALLENGES FOR 6G UBIQUITOUS WIRELESS INTELLIGENCE 6G Research Visions 1 September 20192 | KEY DRIVERS AND RESEARCH CHALLENGES FOR 6G UBIQUITOUS WIRELESS INTELLIGENCE TABLE OF CONTENTS 3 CUTIVE SUMMARY 4 INTRODUCTION 7 SOCIETAL AND BUSINESS DRIVERS FOR 6G 12 6G USE CASES AND NEW DEVICE S 14 6G SPECTRUM AND KPI TARGETS 18 RADIO HARDWARE PROGRESS AND CHALLENGES 22 PHYSICAL LAYER AND WIRELESS SYSTEM 26 6G NETWORKING 29 NEW SERVICE ENABLERS 33 CONTRIBUTORS 6G Research Visions 1 Key Drivers and Research Challenges for 6G Ubiquitous Wireless Intelligence Matti Latva-aho, Kari Leppnen eds. 6G Flagship, University of Oulu, Finland September 2019 ISBN 978-952-62-2353-7 print ISSN 2669-9621 print ISBN 978-952-62-2354-4 online ISSN 2669-963X onlineKEY DRIVERS AND RESEARCH CHALLENGES FOR 6G UBIQUITOUS WIRELESS INTELLIGENCE | 3 CUTIVE SUMMARY Our future society will be increasingly digitised, hyper-connected and globally data driven. Many widely anticipated future services, including eHealth and autonomous vehicles, will be critically dependent on instant, virtually unlimited wireless connectivity. Mobile communication technologies are expected to progress far beyond anything seen so far in wireless-enabled applications, making everyday lives smoother and safer and dramatically improving the efficiency of businesses. As fifth generation 5G research is maturing towards a global standard, the research community must focus on the development of beyond-5G solutions and the 2030 era, i.e. 6G. It is not clear yet what 6G will entail. It will include relevant technologies considered too immature for 5G or which are outside the defined scope of 5G. More specifically, the way in which data is collected, processed, transmitted and consumed within the wireless network will be a key driver for 6G. The first 6G Wireless Summit in March 2019 launched the process of identifying the key drivers, research requirements, challenges and essential research questions related to 6G. This white paper is the first version for the annually revised series of 6G research visions and can be phrased in one vision statement from the first 6G Wireless Summit Ubiquitous wireless intelligence. It is envisioned that we will need new KPI drivers besides the current 5G technical KPIs. Societal megatrends, United Nations UN sustainability goals, lowering carbon dioxide emissions, emerging new technical enablers as well as ever increasing productivity demands are critical drivers towards 2030 solutions. Totally new services such as telepresence and mixed reality will be made possible by high resolution imaging and sensing, accurate positioning, wearable displays, mobile robots and drones, specialized processors, and next-generation wireless networks. Current smart phones are likely to be replaced by pervasive XR experiences with lightweight glasses delivering unprecedented resolution, frame rates, and dynamic range. 6G research should look at the problem of transmitting up to 1 Tbps per user. This is possible through the efficient utilization of the spectrum in the THz regime. Extended spectrum towards THz will enable merging communications and new applications such as 3D imaging and sensing. However, new paradigms for transceiver architecture and computing will be needed to achieve these – there are opportunities for semiconductors, optics and new materials in THz applications to mention a few. Artificial intelligence and machine learning will play a major role both in link and system-level solutions of 6G wireless networks. New access s will be needed for truly massive machine-type communications. Modulation and duplexing schemes beyond Quadrature Amplitude Modulation QAM and Orthogonal Frequency Division Multiplexing OFDM must be developed and possibly it is time to start looking at analogue types of modulation at THz frequencies. Security at all levels of future systems will be much more critical in the future and 6G needs a network with embedded trust. The strongest security protection may be achieved in the physical layer. During the 6G era it will be possible to create data markets, and thus, privacy protection is one key enabler for future services and applications. 6G is not only about moving data around – it will become a framework of services, including communication services where all user-specific computation and intelligence may move to the edge cloud. The integration of sensing, imaging and highly accurate positioning capabilities with mobility will open a myriad of new applications in 6G.4 | KEY DRIVERS AND RESEARCH CHALLENGES FOR 6G UBIQUITOUS WIRELESS INTELLIGENCE INTRODUCTION The arrival of the 5G mobile communications technology is already showing signs of becoming a major factor in driving productivity and is expected to be the key enabler for long-envisaged, highly integrated and autonomous applications in many sectors. This new wave of technology will accelerate the digitalisation of economies and society. Historically, a new mobile “generation” appears approximately every ten years, with 6G expected to emerge around 2030. The first release of 5G New Radio NR – 3GPP Release 15 – was ready in 2018, and global commercialization of 5G is currently taking off. 5G perance and use cases will continue to evolve in the coming releases. 6G will take onboard new technologies and satisfy communication demands going beyond the 5G evolution. Now is the perfect time to identify future communication needs, perance requirements, system and radio challenges, and major technical options for 6G to establish the research goals towards the 2030s. The first 6G Wireless Summit 1was organized in Levi, Finland, in March 2019 with almost 300 participants from 29 countries, including major infrastructure manufacturers, operators, regulators as well as academia. The event was organised by the Finnish 6G Flagship Programme 2 . The 6G vision statement captures the essence of many of the key messages from the event Ubiquitous Wireless Intelligence; Ubiquitous – services follow users everywhere seamlessly; Wireless – wireless connectivity is part of critical infrastructure; Intelligence – context-aware smart services and applications for human and non-human users. Following the summit, a workshop was organized with 70 selected participants to commence the drafting of the first 6G white paper. Each year, the white paper will be updated following the annual 6G Wireless Summit. The goal for this first edition was to identify the key drivers, research requirements, challenges and essential research questions related to 6G. The at of the white paper is deliberately short avoiding lengthy background and justifications; it is targeted primarily at technical experts working in the field. At the highest level, the workshop identified major drivers for 6G Figure 1 sustainability, society, productivity and technology. Is it nave to say “From 5G Engineering to 6G Humanity” or is it imperative In 2016, the UN released 17 Sustainable Development Goals 3SDGs for the 2030 Agenda. These goals were developed against a backdrop of a growing and ageing global population, increasing urbanization and a world in which the climate is changing. If adhered to, the UN SDGs are expected to drive policy and influence government spending in many economies, creating global demand. It is estimated that the world’s population in 2019 is 7.6 billion people, and that this will grow to 8.5 billion by 2030, 9.7 billion by 2050 and 11.2 billion by the end of the current century. As of 2018, 55 of the world’s population lives in urban areas, a proportion that is expected to increase to 68 by 2050 4 . By 2030, the world is projected to have 43 megacities with more than 10 million inhabitants, most of them in developing regions. However, some of the fastest-growing urban agglomerations are cities with fewer than 1 million inhabitants, many of them located in Asia and Africa. 1 2 3See https//www.un.org/sustainabledevelopment/sustainable-development-goals/. 4 Source UN Department of Economic Affairs 2018 Revision of World Urbanization Prospects. Available online https//www.un.org/development/desa/en/news/population/2018-revision-of-world-urbanization-prospects.html.KEY DRIVERS AND RESEARCH CHALLENGES FOR 6G UBIQUITOUS WIRELESS INTELLIGENCE | 5 Figure 1. From 5G Engineering to 6G Humanity – Breaking down the four areas driving 6G research. Urbanization calls for super-efficient ICT services throughout society, which will become more and more automated in all sectors to significantly increase productivity, reduce carbon dioxide emissions and generate cost savings for public expenditure. The future services must be available 24-7, ubiquitously. The services developed for the future urban areas need to be transed for the needs of remote, often rural and very poor areas in order to tackle the UN SDGs. At the same, as societies become heavily dependent on ICT services, they become extremely vulnerable to various types of security threats and attacks. The global threats 5can no longer be ignored when developing future 6G technologies. Further to the societal and SDG drivers, we have included some examples of technology trends and drivers for increased productivity. 5G is envisioned to solve our communication challenges set for 2020s and beyond. However, the first 5G NR release only covers a subset of 5G targets and envisioned use cases. New requirements and technologies are continuously emerging. Some are expected to enter future releases of 5G whereas far more rich requirements and technologies will need to wait for a clean slate of 6G specifications. Some of the emerging and promising directions in technology, described further in later chapters, are listed in Figures 2 and 3.             
x ULL wMP   P P DS   Spp f b  S SD D b L  D b   b p S    z    4D  P j  Xp     p  FSp  P  SP  P  D  Mkf Œ P  U  Ž      Z   p   f G F 
S S      W b S  U b.   f  W kLf    DS   P  P  Q
 W  S G 
qLf  wW Lf L  P G    W b   Sb     P  ,J , S   W  SZ    ,  f  Œb    
    q  P   pf  G pb  p P  D  W k 
G w   Mf F     S 5.0 p GbŒb    
 
  F  SUS L YG
LGY
b  PDU V YV     S
L    5 Source World Economic Forum The Global Risks Report 2019. Available online http//www3.weforum.org/docs/WEF_Global_ Risks_Report_2019.pdf.6 | KEY DRIVERS AND RESEARCH CHALLENGES FOR 6G UBIQUITOUS WIRELESS INTELLIGENCE Figure 2. New wireless hardware and physical layer technologies. Figure 3. Possible technologies for user interface and service enablers. In the remainder of this white paper, key areas for investigation are identified to make the 2030 vision for Ubiquitous Wireless Intelligence a reality. The goal is also to identify essential research questions within the areas of interest. It is acknowledged that this does not a comprehensive list, rather a starting point reflecting the discussions at the first 6G Wireless Summit as well as views from the 6G Flagship programme. Future editions of this white paper will complement the missing areas not discussed at the summit.                                                                
                                         KEY DRIVERS AND RESEARCH CHALLENGES FOR 6G UBIQUITOUS WIRELESS INTELLIGENCE | 7 SOCIETAL AND BUSINESS DRIVERS FOR 6G 5G was primarily developed to address the anticipated capacity growth demand from consumers, as well as the productivity demands from industry, and to enable the increasing importance of Internet of Things IoT. The technical success of 5G has relied on new developments in many areas and will deliver a much wider range of data rates to a much broader variety of devices and users. 6G will require a substantially more holistic approach to identify future communication needs, embracing a much wider community to shape the requirements of 6G. This includes identifying the trends, demands and challenges facing future societies, as well as the global forces shaping our future world to avoid merely commercially driven system definitions. Even though 5G development was shaped by demands from a range of vertical industry sectors, the emphasis has remained on deployments driven by mobile network operators MNOs. 6G will introduce super-efficient short-range connectivity solutions that are likely to be driven by new players in the market resulting in new ecosystems outside traditional MNOs. Having a more inclusive view outside of MNOs will help shape the needs of 6G. Drivers from society, including the UN sustainability goals, will shape 6G. Societal and business drivers will increasingly shape 6G development, including political, economic, social, technological, legal and environmental PESTLE drivers as highlighted in Figure 4. To ensure that the benefits of smart city services and urbanization are fully shared and inclusive, policies to manage urban growth need to ensure access to infrastructure and social services for all, focusing on the needs of the urban poor and other vulnerable groups for housing, education, health care, meaningful work