# The 6G Ecosystem as Support for IoE and Private Networks: Vision, Requirements, and Challenges
## 2 From 1G to 5G
### The Fifth Generation (5G)
To meet the evolving demands for improved performance, portability, interoperability, elasticity, flexibility, reliability, scalability, and spectral and energy efficiency, the progression of mobile networks necessitates a software-driven approach [3; 46], so the 5G core's softwarization capability allows the partitioning of functions into a layered architecture, showcasing remarkable flexibility. Key phases include virtualization--network function virtualization (NFV), service migration, orchestration, and service automation--like service function chaining (SFC) combined with software defined networking (SDN) [47], empowering network operators to maintain cost-effectiveness by minimizing both operational expenses (OPEX) and capital expenditures (CAPEX) [48], shaping the path to 5G and subsequent mobile paradigms [3]. As core and backhaul components of forthcoming mobile networks shift through software transformation, techniques like ultra-dense networks, mMIMO, and high-frequency communication play vital roles in enhancing wireless access networks. These advancements led to 5G's impressive 1000-fold capacity increase over its predecessor [3; 40]. Key performance requirements for 5G encompass data rates of 1 to 10 Gbps, 1 ms RTT latency, heightened capacity for numerous connected devices via wide bandwidth channels, exceptional availability, pervasive connectivity, and a substantial 90% reduction in energy consumption to enhance battery life [3]. The 5G-PPP project introduces a comprehensive five-layered structure comprising infrastructure, network/control, orchestration, business, and services to establish the functional architecture of 5G. Within this framework, the orchestration layer is distributed across the other layers, and the services layer extends from the business layer [49; 50]. The infrastructure layer embodies the RAN connectivity aspect, featuring RATs like non-orthogonal multiple access (NOMA), mMIMO, and coordinated multi-Point (CoMP) transmission to facilitate interface with high-data-capacity small-cells, and mmWave technologies. The control layer oversees network management, while the business layer is responsible for managing network and business services [3; 51; 52]. Nonetheless, the services offered by 5G are insufficient to effectively tackle the evolving needs of various applications, including health technologies and emergency scenarios. In the realm of health services, 5G plays a role by establishing internet connectivity for internet of medical things (IoMT) devices such as wearables and wireless body area networks (WBAN), along with internet of bio-nano things (IoBNT) via mMTC. It also facilitates superior video quality for telemedicine and AR/VR through eMBB, while simultaneously supporting unmanned aerial vehicles (UAV), unmanned ground vehicles (UGV), and autonomous vehicles through URLLC. Nevertheless, these technologies still have some limitations regarding privacy and security, ubiquitous communications in locations with poor infrastructure, connectivity for ultra-dense IoMT devices, and highly reliable and low-latency communications [44; 53]. The 5G technologies offer ultra-reliable, low-latency communications. Still, its short-packet, sensing-based URLLC features hinder ultra-reliable, low-latency services with data-intensive applications like AR, mixed-reality (MR), and VR. The growing number of internet of everything applications calls for integrating communication, sensing, control, and computing functionalities, which are often neglected in the 5G context [18]. Recent progress enables the utilization of ML for tasks like radio-frequency (RF) signal processing, spectrum analysis, and RF spectrum mapping [54; 55]. This integration of AI offers substantial support for precise capacity predictions, automated coverage optimization, efficient network resource scheduling, and network slicing. Ongoing initiatives in 5G networks focus on developing standardized mappings of quality of experience (QoE) to network performance indicators.