Special Topic on New Generation FTTR Communication and Networking Technology

The convergence of optical and wireless technologies is driving the evolution of intelligent indoor networks, with Fiber-to-the-Room (FTTR) emerging as a key architecture for delivering gigabit connectivity in both home and enterprise environments. By deploying optical fiber directly to rooms and integrating it with advanced wireless solutions such as millimeter-wave and Wi-Fi 7, FTTR enables next-generation applications, including immersive VR/AR and industrial IoT. Nevertheless, its large-scale deployment presents challenges in network management, energy efficiency, interference mitigation, and intelligent root cause analysis.

Following a rigorous review process, seven high-quality papers have been selected for this special issue. These works advance FTTR technology through contributions spanning physical layer monitoring, receiver design, energy-saving mechanisms, and AI-driven optimization.

The first paper, “PPON Monitoring Scheme Based on TGD-OFDR with High Spatial Resolution and Dynamic Range,” introduces a time-gated digital optical frequency-domain reflectometry (TGD-OFDR) system that decouples spatial resolution from pulse width. This breakthrough achieves both 0.3 m resolution and 30 dB dynamic range, substantially enhancing passive optical network (PON) monitoring capabilities.

The second paper, “Insights on the Next Generation WLAN: High Experiences (HEX),” identifies poor quality of experience (QoE) as the primary challenge in current WLAN systems. The authors propose making High Experience (HEX) the core objective for next-generation networks through systematic architectural improvements.

The third paper, “FTTR + Millimeter-Wave for Next Generation Indoor High-Speed Communications,” proposes a hybrid FTTR-millimeter-wave architecture, leveraging mmWave's natural isolation to reduce interference while supporting multi-gigabit rates for ultra-high-speed indoor communications.

The fourth paper, “A Transformer-Based End-to-End Receiver Design for Wi-Fi 7 Physical Layer,” proposes a Transformer-based receiver for Wi-Fi 7 that directly decodes OFDM signals without channel estimation, achieving significant performance gains over conventional designs.

The fifth paper, “Root Cause Analysis of Poor FTTR Quality Based on Transformer Mechanisms,” addresses network maintenance challenges in FTTR deployments. The authors develop a multi-task Transformer model that achieves 96.75% accuracy in identifying degraded access points and classifying root causes, outperforming traditional methods significantly.

The sixth paper, “QoS-Aware Energy Saving Based on Multi-Threshold Dynamic Buffer for FTTR Networks,” tackles energy efficiency in dense FTTR deployments. The proposed MBES scheme introduces dynamic buffer thresholds to enable intelligent sleep cycle management while maintaining strict QoS requirements, achieving up to 17.75% energy savings.

The seventh paper, “C-WAN for FTTR: Enabling Low-Overhead Joint Transmission with Deep Learning,” presents a centralized wireless access network solution that addresses synchronization and channel state information overhead in multi-AP coordination. The proposed deep learning model reduces sounding overhead while maintaining transmission performance.

In conclusion, this special issue provides comprehensive coverage of recent advances in FTTR and integrated fiber-wireless systems. We believe that these contributions will serve as valuable references for researchers, engineers, and industry professionals working toward next-generation communication networks. We extend our sincere gratitude to the authors, reviewers, and editorial team members for their dedicated efforts in making this special issue possible.