# 6G Wireless Communication Systems: Applications, Opportunities and Challenges
###### Abstract  
As the technical specifications of the 5 th Generation (5G) wireless communication standard are being wrapped up, there are growing efforts amongst researchers, industrialists, and standardisation bodies on the enabling technologies of a 6G standard or the so-called Beyond 5G (B5G) one. Although the 5G standard has presented several benefits, there are still some limitations within it. Such limitations have motivated the setting up of study groups to determine suitable technologies that should operate in the year 2030 and beyond, i.e., after 5G. Consequently, this Special Issue of _Future Internet_ concerning what possibilities lie ahead for a 6G wireless network includes four high-quality research papers (three of which are review papers with over 412 referred sources and one regular research). This editorial piece summarises the major contributions of the articles and the Special Issue, outlining future directions for new research. future internet technologies; beyond 5G; 6G; COVID-19; pandemic resilient; 6G internet security; enabling technologies; applications; challenges; opportunities +
Footnote †: journal: _Future Internet_  
limitations of the 5G wireless network standard and how they could be resolved in 6G network are discussed in [3]. In [4], holographic radio technology is identified as a critical enabler of the 6G network and should adaptively confront such crises. In addition, the future 6G standard should also forecast the likelihood of both responding to and driving changes in the culture of business modes of operations; remote working, teleworking, face-to-face working, and hybrid working and the innovative technologies that will support these. There are sustainability and security problems too, especially with the proliferation of the Internet of Things (IoT) edge devices. The Third Generation Partnership Project (3 GPP) recommends using orthogonal frequency division multiplexing (OFDM) in the uplink and downlink of 5G networks, although it warns about high power consumption [6]. For IoT and other low-power edge devices, an algorithm for OFDM implementation for 6G applications is provided in [7]. On top of that, industry 4.0 and IoT are interlinked technologies that motivate new technologies and requirements for a next-generation network such as the 6G. Looking at the previous standards, the expected timeline for the emergence and development of a new network standard has been, on average, a decade. For 6G networks, the'real' interest in 6G started around 2018 when a) the International Telecommunications Union (ITU) created The Focus Group NET-2030 to study the potential networks for 2030 and beyond and b) The Third Generation Partnership Project (3 GPP) Group introduced Release 15 (Rel-15 TR 21.915) that discussed V2X communication, unlicensed spectrum use, network slicing, etc., that were aimed at supporting the B5G network. In 2020, the International Telecommunication Union Radio (ITU-Radio) division completed and presented the IMT-2020 5-year plan for the forthcoming B5G network [3]. As the 5G network is expected to reach its limit by 2030, many experts have predicted that year would also mark the birth of the 6G network, coinciding with the conventional decade average length lifespan of the previous network standards. Regarding the enabling technologies that will underpin 6G, existing discussions suggest the need to model internet frameworks that include, for example, holographic internet, data internet, energy internet, internet of things (IoT) and the internet of everything (IoE). Low-power wide area network technologies [8] will support B5G networks for obvious sustainability reasons. For the 6G network standard, future internet will harness the above forms of the internet more intelligently. In other words, artificial intelligence, computational intelligence, machine learning, and deep learning will support the future holographic, data, energy and things internets to play valuable roles [5].