  The sixth-generation (6G) wireless communication network is expected to
integrate the terrestrial, aerial, and maritime communications into a robust
network which would be more reliable, fast, and can support a massive number of
devices with ultra-low latency requirements. The researchers around the globe
are proposing cutting edge technologies such as artificial intelligence
(AI)/machine learning (ML), quantum communication/quantum machine learning
(QML), blockchain, tera-Hertz and millimeter waves communication, tactile
Internet, non-orthogonal multiple access (NOMA), small cells communication,
fog/edge computing, etc., as the key technologies in the realization of beyond
5G (B5G) and 6G communications. In this article, we provide a detailed overview
of the 6G network dimensions with air interface and associated potential
technologies. More specifically, we highlight the use cases and applications of
the proposed 6G networks in various dimensions. Furthermore, we also discuss
the key performance indicators (KPI) for the B5G/6G network, challenges, and
future research opportunities in this domain.
