Açık Radyo Erişim Ağı Üzerine Sistematik Bir İnceleme: Bileşenler, Uygulamalar ve Gelecek Perspektifleri

Open Radio Access Network (O-RAN) introduces a paradigm shift in mobile communications by promoting openness, multi-vendor interoperability, and software-defined networking capabilities as an alternative to traditional RAN architectures. This review study analyzes the architectural structure of O-RAN, its control plane components, and AI-driven network management frameworks. The roles of xApps and rApps operating on Near-Real-Time (Near-RT) and Non-Real-Time (Non-RT) RAN Intelligent Controller (RIC) architectures are examined in the context of resource management and policy-based control. Findings from the literature indicate that O-RAN can be effectively integrated not only into conventional mobile networks but also into emerging use cases such as private 5G networks, UAV-assisted platforms, and digital twin-based network monitoring. However, several technical challenges remain, including timing and synchronization sensitivity, security vulnerabilities, lack of real-world labeled datasets, and ongoing standardization gaps. As we move toward 6G, O-RAN is expected to serve as a foundational architecture supporting autonomous control loops, end-to-end slicing, and high-frequency communication systems. This work aims to provide comprehensive references for researchers and practitioners by consolidating recent developments and outlining future research directions in the O-RAN domain.