Investigation of Optical Signal Regeneration Impact on Power Efficiency of Single-line-rate and Mixed-line-rate Wavelength Division Multiplexing Systems

The requirements for such conflicting parameters as signal transmission speed and quality of transmission continuously increasing on the grounds growing demands of bandwidth-intensive applications like high quality multimedia, extremely detailed, multi-player online gaming and highly capacitive data storage and exchanges. Simultaneous increment of both parameters always leads to power consumption growing, mostly defined by signal regeneration activities, which in its turn stays in contradiction with green network methods. In addition, by existence of the spectral band limitations appropriate for data transmission, the initial system settings and requirements changes from one network to another and can be fulfilled by different network designs with different power efficiency levels. The Wavelength Division Multiplexing (WDM) systems had been developed with the aim to increase information transmission speeds, where the transmission speed of single channel and channel spacing becomes the defining factors for the overall system's capacity. Nevertheless, on the grounds of cross-channel interference, sub-band spacing reduction and usage of high-capacitive signals can adversely affect the system's transmission reach, which will lead to the more frequent signal regeneration. Therefore, the trade-off between transmission speed, quality of transmission and power consumption must be evaluated. In this work authors compare the Single-Line-Rate (SLR) and Multi-Line-Rate (MLR) WDM systems, which uses the most common transmission signals, to demonstrate relation between the enchased spectral efficiency and its impact on the relevant systems power consumption by means of power efficiency and evaluation of 3Rs' (re-amplification, retiming, reshaping) power ratio. The power efficiency was manipulated by different channel spacing. The results are presented as functions of transmitted information volume, which allows adapting the results for transmission systems with different available spectral band.