Comparison of power efficiency and signal regeneration impact in the SLR DWDM transmission systems with different spectral band

The power consumption issue in the wired optical networks has become a major challenge, due to its considerable economic impact and potential adverse influence on the environment. Based on many researches and analytic studies the global internet traffic will continue to increase annually, on the grounds of continuous improvement of bandwidth-intensive applications like transmission of high quality multimedia and capacious data exchange opportunities, which stipulates the requirement of increased information transmission speed at all system layers. In the Wavelength Division Multiplexing (WDM) systems, transmission speed can be enchased by reduction of channel spacing or increment of channel transmission speed. However, owing to interference between operating channels, reduction of sub-band spacing can adversely affect system's transmission reach, by increased number of signal regeneration procedures, which determines the higher power consumption values. In addition, due to the limitations in the spectral band appropriate for data transmission, an available spectral band differs from one network to another, based on the initial requirements for particular system, which can be fulfilled by different network designs with different power consumption values. Therefore the tradeoff between spectral efficiency and required energy consumption should be evaluated. In this work authors compare the Single-Line-Rate (SLR) WDM systems with different available spectral band, which operates on the most commonly used transmission signals, in order to demonstrate relation between the enchased spectral efficiency and its impact on the relevant systems power consumption by means of power efficiency and 3Rs' (reamplification, retiming, reshaping) power ratio evaluation. The results are presented as functions cross-channel intervals and data transmission speed for systems that utilizes entire C-Band (4.4 THz) and systems with limited spectral band.