What should 6G be?


The standardization of fifth generation (5G) communications has been completed, and the 5G network should be commercially launched in 2020. As a result, the visioning and planning of 6G communications has begun, with an aim to provide communication services for the future demands of the 2030s. Here, we provide a vision for 6G that could serve as a research guide in the post-5G era. We suggest that human-centric mobile communications will still be the most important application of 6G and the 6G network should be human centric. Thus, high security, secrecy and privacy should be key features of 6G and should be given particular attention by the wireless research community. To support this vision, we provide a systematic framework in which potential application scenarios of 6G are anticipated and subdivided. We subsequently define key potential features of 6G and discuss the required communication technologies. We also explore the issues beyond communication technologies that could hamper research and deployment of 6G.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: A user’s perception of the different communications networks, from 1G to the hypothetical 6G.

Ivan Gromicho, KAUST

Fig. 2: Five application scenarios supported by 6G communications.

Ivan Gromicho, KAUST

Fig. 3: Qualitative comparison between 5G and 6G communications.

Ivan Gromicho, KAUST


  1. 1.

    Alsharif, M. H. & Nordin, R. Evolution towards fifth generation (5G) wireless networks: current trends and challenges in the deployment of millimetre wave, massive MIMO, and small cells. Telecommun. Syst. 64, 617–637 (2017).

  2. 2.

    David, K. & Berndt, H. 6G vision and requirements: is there any need for beyond 5G? IEEE Veh. Technol. Mag. 13, 72–80 (2018). This publication looks at 6G from the perspective of service.

  3. 3.

    Raghavan, V. & Li, J. Evolution of physical-layer communications research in the post-5G era. IEEE Access 7, 10392–10401 (2019). This paper points out the potential research directions of physical-layer communications in the post -5G era.

  4. 4.

    Yastrebova, A., Kirichek, R., Koucheryavy, Y., Borodin, A. & Koucheryavy, A. Future networks 2030: architecture & requirements. In Proc. IEEE ICUMT 1–8 (2018). This paper details the project of Future Networks 2030.

  5. 5.

    Saad, W., Bennis, M. & Chen, M. A vision of 6G wireless systems: applications, trends, technologies, and open research problems. IEEE Netw. https://doi.org/10.1109/MNET.001.1900287 (2019).

  6. 6.

    Calvanese Strinati, E. et al. 6G: the next frontier: from holographic messaging to artificial intelligence using subterahertz and visible light communication. IEEE Veh. Technol. Mag. 14, 42–50 (2019).

  7. 7.

    Tariq, F. et al. A speculative study on 6G. Preprint at https://arxiv.org/abs/1902.06700 (2019).

  8. 8.

    Chen, S., Zhao, J. & Peng, Y. The development of TD-SCDMA 3G to TD-LTE-advanced 4G from 1998 to 2013. IEEE Wireless Commun. 21, 167–176 (2014).

  9. 9.

    Rissen, J. & Soni, R. The evolution to 4G systems. Bell Labs Tech. J. https://doi.org/10.1002/bltj.20333 (2009).

  10. 10.

    Raivio, Y. 4G-hype or reality. In Proc. Int. Conf. 3G Mobile Commun. Technol. 346–350 (IET, 2001).

  11. 11.

    Dohler, M., Meddour, D., Senouci, S. & Saadani, A. Cooperation in 4G—hype or ripe? IEEE Technol. Soc. Mag. 27, 13–17 (2008).

  12. 12.

    Frias, Z. & Pérez, J. Techno-economic analysis of femtocell deployment in long-term evolution networks. EURASIP J. Wireless Commun. Netw. 2012, 288 (2012).

  13. 13.

    Moral, A. et al. Technoeconomic evaluation of cooperative relaying transmission techniques in OFDM cellular networks. EURASIP J. Adv. Sig. Proc. https://doi.org/10.1155/2011%2F507035 (2011).

  14. 14.

    Wang, Z., Dang, S., Shaham, S., Zhang, Z. & Lv, Z. Basic research methodology in wireless communications: the first course for research-based graduate students. IEEE Access 7, 86678–86696 (2019).

  15. 15.

    Andrews, J. G. et al. What will 5G be? IEEE J. Sel. Area. Commun. 32, 1065–1082 (2014).

  16. 16.

    Parkvall, S., Dahlman, E., Furuskar, A. & Frenne, M. NR: the new 5G radio access technology. IEEE Commun. Stand. Mag. 1, 24–30 (2017).

  17. 17.

    Patzold, M. 5G is coming around the corner. IEEE Veh. Technol. Mag. 14, 4–10 (2019). This editorial summarizes the latest achievements of 5G research deployment.

  18. 18.

    Dohler, M., Heath, R. W., Lozano, A., Papadias, C. B. & Valenzuela, R. A. Is the PHY layer dead? IEEE Commun. Mag. 49, 159–165 (2011). This paper describes a number of common issues that have lasted for a long time in the research community of wireless communications.

  19. 19.

    Clazzer, F. et al. From 5G to 6G: has the time for modern random access come? Preprint at https://arxiv.org/abs/1903.03063 (2019).

  20. 20.

    Zhang, Z. et al. 6G wireless networks: vision, requirements, architecture, and key technologies. IEEE Veh. Technol. Mag. 14, 28–41 (2019).

  21. 21.

    Rommel, S., Raddo, T. R. & Monroy, I. T. Data center connectivity by 6G wireless systems. In Proc. IEEE PSC https://doi.org/10.1109/PS.2018.8751363 (IEEE, 2018).

  22. 22.

    Giordani, M., Polese, M., Mezzavilla, M., Rangan, S. & Zorzi, M. Towards 6G networks: use cases and technologies. Preprint at https://arxiv.org/abs/1903.12216 (2019).

  23. 23.

    Yanikomeroglu, H. Integrated terrestrial/non-terrestrial 6G networks for ubiquitous 3D super-connectivity. In Proc. 21st ACM Int. Conf. Modeling, Analysis and Simulation of Wireless and Mobile Systems 3–4 (ACM, 2018).

  24. 24.

    Yaacoub, E. & Alouini, M.-S. A key 6G challenge and opportunity—connecting the remaining 4 billions: a survey on rural connectivity. Preprint at https://arxiv.org/abs/1906.11541 (2019).

  25. 25.

    Mahmood, N. H. et al. Six key enablers for machine type communication in 6G. Preprint at https://arxiv.org/abs/1903.05406 (2019).

  26. 26.

    Rappaport, T. S. et al. Wireless communications and applications above 100 GHz: opportunities and challenges for 6G and beyond. IEEE Access 7, 78729–78757 (2019).

  27. 27.

    Stoica, R.-A. & de Abreu, G. T. F. 6G: the wireless communications network for collaborative and AI applications. Preprint at https://arxiv.org/abs/1904.03413 (2019).

  28. 28.

    Letaief, K. B., Chen, W., Shi, Y., Zhang, J. & Zhang, Y. A. The roadmap to 6G: AI empowered wireless networks. IEEE Commun. Mag. 57, 84–90 (2019).

  29. 29.

    Nawaz, S. J., Sharma, S. K., Wyne, S., Patwary, M. N. & Asaduzzaman, M. Quantum machine learning for 6G communication networks: state-of-the-art and vision for the future. IEEE Access 7, 46317–46350 (2019).

  30. 30.

    Renzo, D. et al. Smart radio environments empowered by reconfigurable AI meta-surfaces: an idea whose time has come. EURASIP J. Wireless Commun. Netw. 2019, 129 (2019).

  31. 31.

    Zhao, J. A Survey of intelligent reflecting surfaces (IRSs): towards 6G wireless communication networks. Preprint at https://arxiv.org/abs/1907.04789v3 (2019).

  32. 32.

    Nadeem, Q.-U.-A., Kammoun, A., Chaaban, A., Debbah, M. & Alouini, M.-S. Asymptotic max-min SINR analysis of reconfigurable intelligent surface assisted MISO systems. Preprint at https://arxiv.org/abs/1903.08127v3 (2019).

  33. 33.

    Nadeem, Q.-U.-A., Kammoun, A., Chaaban, A., Debbah, M. & Alouini, M.-S. Intelligent reflecting surface assisted wireless communication: modeling and channel estimation. Preprint at https://arxiv.org/abs/1906.02360v2 (2019).

  34. 34.

    Basar, E. Reconfigurable intelligent surface-based index modulation: a new beyond MIMO paradigm for 6G. Preprint at https://arxiv.org/abs/1904.06704v2 (2019).

  35. 35.

    Oh, J., Thiel, M. & Sarabandi, K. Wave-propagation management in indoor environments using micro-radio-repeater systems. IEEE Antenn. Propag. Mag. 56, 76–88 (2014).

  36. 36.

    Dang, S., Ma, G., Shihada, B. & Alouini, M.-S. Enabling smart buildings by indoor visible light communications and machine learning. Preprint at https://arxiv.org/abs/1904.07959 (2019).

  37. 37.

    Ullah, S. et al. A comprehensive survey of wireless body area networks. J. Med. Syst. 36, 1065–1094 (2012).

  38. 38.

    Li, X., Hong, S., Chakravarthy, V. D., Temple, M. & Wu, Z. Intercarrier interference immune single carrier OFDM via magnitude-keyed modulation for high speed aerial vehicle communication. IEEE Trans. Commun. 61, 658–668 (2013).

  39. 39.

    Zhang, X., Cheng, W. & Zhang, H. Heterogeneous statistical QoS provisioning over airborne mobile wireless networks. IEEE J. Sel. Area. Commun. 36, 2139–2152 (2018).

  40. 40.

    Philbeck, I. Connecting the Unconnected: Working Together to Achieve Connect 2020 Agenda Targets. In Special Session of the Broadband Commission and the World Economic Forum at Davos Annual Meeting (Broadband Commission, 2017).

  41. 41.

    Gopal, R. & BenAmmar, N. Framework for unifying 5G and next generation satellite communications. IEEE Netw. 32, 16–24 (2018).

  42. 42.

    Dang, S., Coon, J. P. & Chen, G. Outage performance of two-hop OFDM systems with spatially random decode-and-forward relays. IEEE Access 5, 27514–27524 (2017).

  43. 43.

    Saeed, N., Celik, A., Al-Naffouri, T. Y. & Alouini, M.-S. Underwater optical wireless communications, networking, and localization: a survey. Ad Hoc Netw. 94, 101935 (2019).

  44. 44.

    Zeng, Z., Fu, S., Zhang, H., Dong, Y. & Cheng, J. A survey of underwater optical wireless communications. IEEE Commun. Surv. Tut. 19, 204–238 (2017).

  45. 45.

    Dohler, M. et al. Internet of skills, where robotics meets AI, 5G and the Tactile Internet. In Proc. IEEE EuCNC https://doi.org/10.1109/EuCNC.2017.7980645 (IEEE, 2017).

  46. 46.

    5G communications for automation in vertical domains. 5G Americas https://go.nature.com/2th2xi0 (2018).

  47. 47.

    Voigtlander, F. et al. 5G for robotics: ultra-low latency control of distributed robotic systems. In Proc. IEEE ISCSIC 69–72 (IEEE, 2017).

  48. 48.

    Cheng, N. et al. Big data driven vehicular networks. IEEE Netw. 32, 160–167 (2018).

  49. 49.

    Wakunami, K. et al. Projection-type see-through holographic three-dimensional display. Nat. Commun. 7, 12954 (2016).

  50. 50.

    Simsek, M., Aijaz, A., Dohler, M., Sachs, J. & Fettweis, G. 5G-enabled tactile internet. IEEE J. Sel. Area. Commun. 34, 460–473 (2016).

  51. 51.

    Kim, K. S. et al. Ultrareliable and low-latency communication techniques for tactile Internet services. Proc. IEEE 107, 376–393 (2019).

  52. 52.

    Prasad, R. Human bond communication. Wireless Pers. Commun. 87, 619–627 (2016).

  53. 53.

    Khalid, M., Amin, O., Ahmed, S., Shihada, B. & Alouini, M.-S. Communication through breath: aerosol transmission. IEEE Commun. Mag. 57, 33–39 (2019).

  54. 54.

    Shi, H., Prasad, R. V., Onur, E. & Niemegeers, I. G. M. M. Fairness in wireless networks: issues, measures and challenges. IEEE Commun. Surv. Tut. 16, 5–24 (2014).

  55. 55.

    Haenggi, M., Andrews, J. G., Baccelli, F., Dousse, O. & Franceschetti, M. Stochastic geometry and random graphs for the analysis and design of wireless networks. IEEE J. Sel. Area. Commun. 27, 1029–1046 (2009).

  56. 56.

    Nadeem, Q.-U.-A., Kammoun, A. & Alouini, M.-S. Elevation beamforming with full dimension MIMO architectures in 5G systems: a tutorial. IEEE Commun. Surv. Tut. 21, 3238–3273 (2019).

  57. 57.

    Chen, L. et al. Report on Post-Quantum Cryptography https://doi.org/10.6028/NIST.IR.8105 (NIST, 2016).

  58. 58.

    Shiu, Y., Chang, S. Y., Wu, H., Huang, S. C. & Chen, H. Physical layer security in wireless networks: a tutorial. IEEE Wireless Commun. 18, 66–74 (2011).

  59. 59.

    Harrison, K. A., Munro, W. J., Rarity, J. G. & Duligall, J. L. Quantum key distribution apparatus and method. US patent 8,054,976 (2011).

  60. 60.

    Obeed, M., Salhab, A. M., Alouini, M.-S. & Zummo, S. A. On optimizing VLC networks for downlink multi-user transmission: a survey. IEEE Commun. Surv. Tut. 21, 2947–2976 (2019).

  61. 61.

    Niemiec, M. & Pach, A. R. Management of security in quantum cryptography. IEEE Commun. Mag. 51, 36–41 (2013).

  62. 62.

    Henry, R., Herzberg, A. & Kate, A. Blockchain access privacy: challenges and directions. IEEE Secur. Priv. 16, 38–45 (2018).

  63. 63.

    Van Huynh, N. et al. Ambient backscatter communications: a contemporary survey. IEEE Commun. Surv. Tut. 20, 2889–2922 (2018).

  64. 64.

    Madan, R., Mehta, N. B., Molisch, A. F. & Zhang, J. Energy-efficient cooperative relaying over fading channels with simple relay selection. IEEE Trans. Wireless Commun. 7, 3013–3025 (2008).

  65. 65.

    Yunas, S. F., Valkama, M. & Niemelä, J. Spectral and energy efficiency of ultra-dense networks under different deployment strategies. IEEE Commun. Mag. 53, 90–100 (2015).

  66. 66.

    Ulukus, S. et al. Energy harvesting wireless communications: a review of recent advances. IEEE J. Sel. Area. Commun. 33, 360–381 (2015).

  67. 67.

    Li, J. L., Krairiksh, M., Rahman, T. A. & Al-Shamma’a, A. Keynote speakers: wireless power transfer: from long-distance transmission to short-range charging. In 2013 IEEE Int. RF Microwave Conf. (RFM) https://doi.org/10.1109/RFM.2013.6757202 (IEEE, 2013).

  68. 68.

    Mao, Q., Hu, F. & Hao, Q. Deep learning for intelligent wireless networks: a comprehensive survey. IEEE Commun. Surv. Tut. 20, 2595–2621 (2018).

  69. 69.

    Yang, L. & Wang, F. Driving into intelligent spaces with pervasive communications. IEEE Intell. Syst. 22, 12–15 (2007).

  70. 70.

    Basar, E. et al. Wireless communications through reconfigurable intelligent surfaces. IEEE Access 7, 116753–116773 (2019).

  71. 71.

    Javaid, N., Sher, A., Nasir, H. & Guizani, N. Intelligence in IoT-based 5G networks: opportunities and challenges. IEEE Commun. Mag. 56, 94–100 (2018).

  72. 72.

    Belmonte-Hernández, A., Hernández-Peñaloza, G., Martín Gutiérrez, D. & Álvarez, F. SWiBluX: multi-sensor deep learning fingerprint for precise real-time indoor tracking. IEEE Sens. J. 19, 3473–3486 (2019).

  73. 73.

    Zhu, N. et al. Bridging e-health and the Internet of Things: the SPHERE project. IEEE Intell. Syst. 30, 39–46 (2015).

  74. 74.

    Alzenad, M., Shakir, M. Z., Yanikomeroglu, H. & Alouini, M.-S. FSO-based vertical backhaul/fronthaul framework for 5G+ wireless networks. IEEE Commun. Mag. 56, 218–224 (2018).

  75. 75.

    Kishk, M. A., Bader, A. & Alouini, M.-S. Capacity and coverage enhancement using long-endurance tethered airborne base stations. Preprint at https://arxiv.org/abs/1906.11559 (2019).

  76. 76.

    Elayan, H., Amin, O., Shihada, B., Shubair, R. M. & Alouini, M. Terahertz band: the last piece of RF spectrum puzzle for communication systems. IEEE Open J. Commun. Soc. https://doi.org/10.1109/OJCOMS.2019.2953633 (2020).

  77. 77.

    Sengupta, K., Nagatsuma, T. & Mittleman, D. M. Terahertz integrated electronic and hybrid electronic–photonic systems. Nat. Electron. 1, 622–635 (2018).

  78. 78.

    Nagatsuma, T., Ducournau, G. & Renaud, C. C. Advances in terahertz communications accelerated by photonics. Nat. Photon. 10, 371–379 (2016).

  79. 79.

    Drake, F. Mobile phone masts: protesting the scientific evidence. Publ. Underst. Sci. 15, 387–410 (2006).

  80. 80.

    Tesanovic, M. et al. The LEXNET project: wireless networks and EMF: paving the way for low-EMF networks of the future. IEEE Veh. Technol. Mag. 9, 20–28 (2014).

  81. 81.

    Pieters, W. Explanation and trust: what to tell the user in security and AI? Ethics Inf. Technol. 13, 53–64 (2011).

  82. 82.

    Yang, H. & Alouini, M.-S. Data-oriented wireless transmission in future wireless systems: toward trustworthy support of advanced Internet of Things. IEEE Veh. Technol. Mag. 14, 78–83 (2019).

Download references

Author information

M.-S.A. and B.S. conceived the work and suggested the outline of the paper. S.D. and O.A. carried out investigations and wrote the paper.

Correspondence to Shuping Dang.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Dang, S., Amin, O., Shihada, B. et al. What should 6G be?. Nat Electron 3, 20–29 (2020). https://doi.org/10.1038/s41928-019-0355-6

Download citation