Improved sustainability in WDM transport-network elements

Sustainability has become a ubiquitous requirement, driven by global warming and resource scarcity. For Wavelength-Division Multiplexing (WDM) and other telecommunications equipment, the by far most-relevant environmental aspect is in-service energy consumption (CO₂), which is only then followed by resources usage during production (raw material, energy, CO₂), all transportation (CO₂), and recycling potential. Consequently, eco design has to address these aspects first, and it did in the past. For example, per-bit-rate energy consumption decreased from ~10 W/Gb/s in 1996 to ~0.5 W/Gb/s now. This is supported by several TEER (Telecommunications Energy Efficiency Rating) documents and standards. Similarly, most material-usage aspects and PCB size were reduced in a similar way. These improvements, however, are limited by the fact that bit rates are exponentially increasing. Therefore, further improvements have to be supported by Circular Economy and its aspects of re-use, refurbishment and optimized recycling.