@article{955eb0bf47d24c0c81a630443c13ca21,
title = "6G Wireless Systems: A Vision, Architectural Elements, and Future Directions",
abstract = "Internet of everything (IoE)-based smart services are expected to gain immense popularity in the future, which raises the need for next-generation wireless networks. Although fifth-generation (5G) networks can support various IoE services, they might not be able to completely fulfill the requirements of novel applications. Sixth-generation (6G) wireless systems are envisioned to overcome 5G network limitations. In this article, we explore recent advances made toward enabling 6G systems. We devise a taxonomy based on key enabling technologies, use cases, emerging machine learning schemes, communication technologies, networking technologies, and computing technologies. Furthermore, we identify and discuss open research challenges, such as artificial-intelligence-based adaptive transceivers, intelligent wireless energy harvesting, decentralized and secure business models, intelligent cell-less architecture, and distributed security models. We propose practical guidelines including deep Q-learning and federated learning-based transceivers, blockchain-based secure business models, homomorphic encryption, and distributed-ledger-based authentication schemes to cope with these challenges. Finally, we outline and recommend several future directions.",
keywords = "5G, 6G, blockchain, federated learning, Internet of Everything, Internet of Things, meta learning",
author = "Khan, {Latif U.} and Ibrar Yaqoob and Muhammad Imran and Zhu Han and Hong, {Choong Seon}",
note = "Funding Information: Different organizations have started 6G projects [18]–[21]. The 6G Flagship research program [18] is supported by the Academy of Finland and led by the University of Oulu to carry out the co-creation of an ecosystem for 6G innovation and 5G adoption. The vision of the 6G flagship program is a data-driven society with unlimited, instant wireless connectivity. Initially, five organizations; namely, VTT Technical Research Center of Finland Ltd., Oulu University of Applied Sciences, Nokia, Business Oulu, and Aalto University, joined the program as collaborators. Later, InterDigital and Keysight Technologies joined the program. An agreement was signed between the South Korean government and the University of Oulu, Finland for the development of 6G technology [19]. Furthermore, LG has established its first research laboratory at the Korea Advanced Institute of Science and Technology to carry out 6G research activities [20]. SK Telecom started joint research on 6G with Samsung, Nokia, and Ericsson [21]. Research on 6G has started in China, as officially announced by the Ministry of Science and Technology [22]. Moreover, the Chinese vendor Huawei has already started 6G research at its research center in Ottawa, Canada [23]. Several 6G research programs have been started in the US, as announced by the US president [24]. Additionally, the NYU WIRELESS research center, which comprises nearly 100 faculty members and graduate students, is working on communication foundations, machine learning, quantum nanodevices, and 6G testbeds [25]. Existing 6G tutorials and surveys are discussed next. Funding Information: This work was supported in part by the Institute of Information and Communications Technology Planning and Evaluation (IITP) Grant funded by the Korean Government Ministry of Science and ICT (MSIT), South Korea, Evolvable Deep Learning Model Generation Platform for Edge Computing, under Grant 2019-0-01287, and in part by MSIT through the Grand Information Technology Research Center Support Program, supervised by the Institute for Information and Communications Technology Planning and Evaluation (IITP), under Grant IITP-2020-2015-0-00742. Publisher Copyright: {\textcopyright} 2013 IEEE.",
year = "2020",
doi = "10.1109/ACCESS.2020.3015289",
language = "British English",
volume = "8",
pages = "147029--147044",
journal = "IEEE Access",
issn = "2169-3536",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
}