Power Consumption Considerations in Optical Metro Transport Networks#

Steve Jones

• Why: Power is becoming a first-order constraint on transport design — the deck cites telecom at 2–3% of humanity's power consumption and energy at 20–40% of telco OPEX. For the PM this is the physical-layer/WAN-transport side of their core interests with concrete, quantified trade-offs.
• What: A per-link power model (1G–400G, 10–80 km metro links) comparing passive WDM (colored transceivers in the host) against active transponding and muxponding. Headline results: transponding consumes ~4–5× the power of passive WDM per link, muxponding ~10–20×; worst-case deployments (hot-running industrial-temp optics, underutilized chassis, data-sheet-based cooling sizing) can exceed technologically-necessary power by >100×.
• How: Bottom-up model from ~10 manufacturers' data sheets, normalized per link: chassis/PSU/fan/management-card overhead amortized per line, client TRX power modeled at typical rather than max (direct-detect 1–25G parts actually draw ~40–60% of data-sheet max — 97% of sampled products consume under half of spec; coherent ≥100G ~75–90%), cooling approximated at a 2× multiplier. Muxponding compared against the equivalent client-rate alternative, not the line rate.
• Where applicable: Broadly applicable to metro DC-interconnect and carrier transport decisions; the model is deliberately parametric. Caveat: the speaker is affiliated with Huber+SUHNER/Cube Optics, a passive-WDM vendor, and the analysis strongly favors passive WDM — the numbers are useful, the framing is vendor-adjacent. Operators mixing passive and active WDM on the same metro plant is the recommended real-world pattern.