QoS-Aware Energy Saving Based on Multi-Threshold Dynamic Buffer for FTTR Networks

Abstract: As Fiber-to-the-Room (FTTR) networks proliferate, multi-device deployments pose significant energy consumption challenges. This paper proposes a Quality of Service (QoS)-aware energy-saving scheme based on a multi-threshold dynamic buffer (MBES) to reduce energy QoS. MBES leverages the centralized control of the main fiber unit (MFU) and the wireless-state awareness of subordinate fiber units (SFUs) for synergistic fiber-wireless energy savings. The scheme assigns independent, dynamic buffer thresholds to service queues on SFUs, enabling low-latency reporting for high-priority traffic while accumulating low-priority data to extend sleep cycles. At the MFU, a coordinated scheduling algorithm accounts for Wi-Fi access delay and creates an adaptive closed-loop control by adjusting SFUs’ buffer thresholds based on end-to-end delay feedback. Simulation results show that, while satisfying strict latency requirements, MBES achieves a maximum energy saving of 17.75% compared with the scheme with No Energy Saving (NES) and provides a superior trade-off between latency control and energy efficiency compared with the Energy-Saving scheme based on a Single-threshold Buffer (SBES).

Keywords: fiber to the room; power consumption; energy consumption; energy saving