This book serves as a comprehensive introduction to the disruptive Fully Decoupled Radio Access Network (FD-RAN) architecture. A broad spectrum of the key enabling technologies are covered and organized into four themes: Physical Layer Transmission, Resource Management, Cost-efficient Operations, as well as Prototype and Potential Applications. It provides rethinking of network architecture and offers a unique solution to tackle the fundamental challenges and align with future demands of 6G. FD-RAN has emerged as a promising 6G architecture, with the following design objectives: decoupling, flexibility, simplicity, openness, intelligence, and cooperation. At its core, FD-RAN decomposes traditional base stations into three distinct functional entities: Control Signaling, Uplink Data Transmission, and Downlink Data Transmission. This decoupling enables flexible cooperation and allows independent optimization of uplink and downlink operations, leading to potential resource utilization improvement and network cost reduction. This book is particularly valuable for professionals, researchers, and stakeholders in academia, industry and standardization bodies, who are engaged in the development of next-generation mobile communication systems. This book presents novel concepts and solutions designed to support a more flexible, efficient, and forward-looking vision for 6G networks. Advanced-level students majoring in communications engineering/computer science can also find valuable content and inspiration from this book.
