Performance Evaluation of OSNR Sensitivity in DWDM-ROADM System for Data Center Interconnection

The growing demand for handling sensitive data and high-bandwidth applications has made Data Center Interconnection (DCI) very important, as it provides high-bandwidth connectivity to improve efficiency. To address the increasing need for reliable, high-performance data transport, experts are evaluating the performance of Dense Wavelength Division Multiplexing (DWDM) integrated with Reconfigurable Optical Add-Drop Multiplexers (ROADM) system. Therefore, this study aimed to determine the optimal Optical Signal-to-Noise Ratio (OSNR) required for DWDM-ROADM system to transmit a 400 $\mathrm{Gb} / \mathrm{s}$ client interface operating at an $800 \mathrm{~Gb} / \mathrm{s}$ line-side rate. System configuration used a channel spacing of 150 GHz at a wavelength of $\mathbf{1 9 3. 1 5 0} \mathbf{~ T H z}$. Furthermore, OSNR performance evaluation was carried out by analyzing noise levels from Variable Optical Attenuator (VOA) and pre-Forward Error Correction (pre-FEC) setting. The results showed that DWDM-ROADM system required OSNR sensitivity value of $\mathbf{2 3. 1 5} \mathbf{d B}$ to ensure reliable $400 \mathrm{~Gb} / \mathrm{s}$ traffic transmission. This value was achieved at pre-FEC bit error rate (BER) of 0.02 and VOA attenuation of 8 dB, while capable of transmitting $400 \mathrm{~Gb} / \mathrm{s}$ of traffic. System performance was more stable at VOA level of 8 dB compared to 6 dB, where the traffic experiences errors at BER $1.63 \times 10^{-11}$. Finally, this study proposed a new test methodology for determining the minimum OSNR required for DWDM-ROADM system to reliably transmit $400 \mathrm{~Gb} / \mathrm{s}$ of traffic.