A Review of 6G Conceptual Components, Ultra-Dense Networks, and Research Challenges Towards Cyber-Physical-Social Systems

Next-generation wireless network applications that combine the Internet of Things (IoT), intelligent edges, and connectivity technologies will benefit every area, including e-health and medical Internet of Things (M-IoT). The fifth generation (5G) mobile network technology cannot match the requirements of emerging mobile apps, which require extreme communication speed, network intelligence, ultra-low latency, comprehensive connectivity, and the capacity to manage diversely related usages. The sixth generation (6G) mobile network technology establishes new performance standards that the fifth generation (5G) mobile network technology could not satisfy. For incredibly immersive applications such as 3D communications and enormous virtual reality (VR)/ extended reality (XR) applications to be economically viable, 6G capabilities must be delivered at a large scale. Deploying several tiny cells to construct ultra-dense networks (UDN) is one option for tackling the extraordinary rise in capacity and coverage needs. The proposed work estimates that only the future 6G networks can deliver a high-performance connection with many connected devices, particularly in challenging situations such as diverse mobility, energetic environments, and extreme density. Accordingly, this article discusses the most current and forthcoming 6G network-compatible advancements to comprehensively review 6G mobile communication technologies in single survey research. At the outset, we thoroughly overview UDN and the 6G system's goals, motivations, requirements, architecture, and conceptual parts.