# The 6G Ecosystem as Support for IoE and Private Networks: Vision, Requirements, and Challenges
## 4 The Requirements of 6G
### Network Architecture
AI-enabled network optimization continuously monitors KPIs in real time, swiftly adapting network parameters to ensure an exceptional QoE. In 6G, native-AI will significantly influence the network's physical layer, enhancing tasks such as estimation or prediction of channel conditions, modulation classification, adaptative coding, and security [54; 88]. Deep reinforcement learning will be employed for resource allocation at the data link layer [89], while the transport layer will see the application of algorithms for route computation and intelligent traffic prediction [16]. The design of 6G should aim for a genuine convergence of communication and computing, enabling users' diverse devices to tap into the network's available computational resources effortlessly. The H2020 EU-funded Hexa-X proposes an architecture based on three layers: infrastructure, network service, and application [59]. The infrastructure layer, which provides physical resources to host network service and application layer, incorporates network RAN, network CN, and transport networks based on radio equipment like non-virtualized radio functions such as radio units (RUs), distributed units (DU), and BS, switches, routers, communication links, data centers, and cloud infrastructure. Based on the new features of RAN enhancements, it enables a high data rate, extremely low latency, high reliability, availability, high capacity, affordable coverage, high energy efficiency, high localization accuracy, and integrated sensing functionalities. Within the framework of 6G architecture, a diverse array of (sub)network solutions converge to form a comprehensive network of networks. This dynamic structure possesses the innate ability to conform to novel topologies readily and flexibly, effectively addressing the demands for exceptional performance and extensive global service coverage. The 6G network service layer is designed with a foundation in the cloud and micro-service-based technology, utilizing services that span from the central cloud to the far edges, encompassing devices beyond the RAN. This expansion of microservices across network functions, operations, and applications lays the groundwork for a softwarised, AI-driven, and efficient 6G architecture. To create an intelligent network, support for AI in 6G and AlaaS is crucial, alongside advancements in programmability and network automation. Embracing a cloud-native approach further simplifies RAN and CN architectures, reducing complexity by eliminating redundant processing points for specific messages and minimizing duplication of functionalities among functions. In the era of 6G, there is a significant and anticipated focus on merging the functionalities of both 5G RAN and its core components. This consolidation aims to streamline functional elements, culminating in a core-less RAN structure that offers enhanced precision in the user plane [64]. Cloud-native technologies will be crucial in establishing edge-based cloudlets, enabling seamless communication between applications and functions. This capability will serve many interconnected assets while accommodating dynamic and flexible mesh topologies to deal with the highly heterogeneous network of devices and technologies, encompassing variations in both hardware and software. Security and privacy mechanisms are intrinsic components of the comprehensive architecture, impacting every network layer along with the management and orchestration domain [59]. Pursuing the elevated spectrum and energy efficiency mandates the integration of novel air interface and communication technologies. This encompasses the adoption of new waveforms, diversified multiple-access methods, advanced channel encoding techniques, multi-antenna technologies, and the strategic amalgamation of these diverse approaches. Concurrently, evolution necessitates innovative network architectures. These include paradigms like SDN and NFV, dynamic network slicing (DNS), service-based architecture (SBA), cognitive service architecture (CSA), and cell-free (CF) architectures.