GREEN FTTH: ENERGY EFFICIENCY OF ACCESS NETWORKS AND SUSTAINABLE DESIGNS
DOI:
https://doi.org/10.18623/rvd.v23.5511Keywords:
FTTH, Passive Optical Networks, Energy Efficiency, Sustainable Design, Broadband Access, Green Telecommunications, PON, Network DecarbonizationAbstract
Fiber-to-the-home (FTTH) has moved from a capacity upgrade option to a strategic sustainability choice for broadband access. Compared with copper-intensive access networks, FTTH reduces the number of active field elements, lowers maintenance intensity, and creates a better foundation for long-term decarbonization. Yet “green FTTH” is not automatic. As traffic volumes increase, access operators still face rising electricity demand from optical line terminals (OLTs), optical network units (ONUs), customer-premises equipment (CPE), cooling systems, and supporting facilities. This review paper synthesizes literature published between 2020 and 2025 to examine how FTTH and related passive optical access architectures can be designed, operated, and upgraded for higher energy efficiency and broader environmental sustainability. Following a structured review approach, the paper analyzes five themes: comparative energy performance of access architectures; device-level and protocol-level power-saving methods; network design, migration, and resilience strategies; life-cycle and circular-economy considerations; and future directions associated with AI-enabled operations, fixed-mobile convergence, and next-generation PON evolution. The review finds that FTTH, especially GPON- and XGS-PON-based passive architectures, consistently outperforms legacy copper and hybrid alternatives in energy-per-bit and energy-per-subscriber terms when migration is accompanied by copper retirement and careful CPE optimization (Europacable, 2022; World Broadband Association [WBBA], 2024). However, the environmental outcome depends increasingly on operational practices beyond the optical distribution network itself, especially sleep/doze modes, dynamic bandwidth allocation, centralized and simplified architectures, renewable power integration, facility efficiency, repair logistics, and the embodied impacts of equipment manufacturing (Khalili et al., 2020; Lorincz et al., 2025; Telefónica, 2022). The paper concludes that sustainable FTTH design requires a whole-system view in which architecture, electronics, software control, customer equipment, and circular procurement policies are treated as one optimization problem rather than as separate engineering layers.
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