Balancing Energy Efficiency and Device Lifetime in TWDM-PON Under Traffic Fluctuations.

Energy-efficient time- and wavelength-division multiplexed passive optical network has been intensely investigated. However, conventional schemes aimed at energy efficiency may bring about repeated power-state transitions between sleep mode and active mode, resulting in periodic device-temperature cycling and frequent wavelength reassignment, which will greatly deteriorate network quality of service. These side effects become non-trivial when traffic fluctuates sharply as expected in the future. In this letter, we propose a wavelength-postponed-switching-off (WPS) strategy to reduce power-state transitions by means of postponing the power-off of redundant wavelengths. Redundant wavelengths represent wavelengths that are supposed to be powered off by conventional schemes when traffic declines. Illustrative results show that, the WPS strategy can provide a balanced performance of both energy efficiency and device lifetime, while decreasing service interruption caused by turning ON or OFF the equipment.