Juliano R. F. Oliveira

EDFA adaptive gain control effect analysis over an amplifier cascade in a DWDM optical system

In this paper, we analyze the EDFA adaptive gain control impact on 80 modulated C-band channels (10 Gbps NRZ) in a DWDM optical system composed of four cascaded amplifiers. System performance was evaluated in terms of channels optical signal-to-noise ratio (OSNR), noise figure (NF), bit error rate (BER), and gain flatness (GF) measurements. The adaptive EDFA scheme aims to optimize NF and GF spectra by adjusting its setpoint gain based on static information about these parameters and was improved here to prioritize NF when BER of the received signal remains under the FEC limit.

Demonstration of EDFA cognitive gain control via GMPLS for mixed modulation formats in heterogeneous optical networks

We demonstrate cognitive gain control for EDFA operation in real-time GMPLS controlled heterogeneous optical testbed with 10G/100G/200G/400G lightpaths. Cognitive control maintains the network BER below FEC-limit for up to 6 dB of induced attenuation penalty.

Hybrid EDFA/Raman Amplification Topology for Repeaterless 4.48 Tb/s (40 x 112 Gb/s DP-QPSK) Transmission Over 302 Km of G.652 Standard Single Mode Fiber

In this work we carry out a comprehensive experimental study on hybrid optical amplification topologies (based on first order Raman and Erbium doped fiber amplifiers) for repeaterless transmission of 112 Gb/s dual polarization-quadrature phase shift keying (DP-QPSK) enabling a 4.48 Tb/s (40 × 112 Gb/s) transmission over 302 km of standard single mode fiber with coherent detection. Hybrid optical amplification was employed for signal boosting and pre-amplification and repeaterless transmission is assured without the use of neither in-line amplification nor remote optical amplifiers. The goal was to achieve the highest bandwidth-distance product for repeaterless DWDM transmission systems over legacy fiber without any in-line amplification technology. The achieved result is a significant milestone, when compared to recent state-of-the-art investigations.

Global WSS-based equalization strategies for SDN metropolitan mesh optical networks

We experimentally demonstrate the benefits of global (end-to-end) WSS-based spectrum equalization for multiple ROADMs in cascade. We introduce three equalization strategies to enable OSNR enhancement in a SDN metropolitan mesh optical network test-bed with 80 × 128 Gb/s.

An optical SDN Controller for Transport Network virtualization and autonomic operation

This paper proposes an architecture for Software Defined Optical Transport Networks. The SDN Controller includes a network abstraction layer allowing the implementation of cognitive controls and policies for autonomic operation, based on global network view. Additionally, the controller implements a virtualized GMPLS control plane, offloading and simplifying the network elements, while unlocking the implementation of new services such as optical VPNs, optical network slicing, and keeping standard OIF interfaces, such as UNI and NNI. The concepts have been implemented and validated in a real testbed network formed by five DWDM nodes equipped with flexgrid WSS ROADMs.

Towards software defined autonomic terabit optical networks

This paper presents an Optical SDN architecture and implementation enabled for virtual optical networks, supporting adaptive and cognitive algorithms to enhance QoT. The paper also shows experimental results of a software-defined autonomic flexible transponder.

Low Complexity Advanced DBP Algorithms for Ultra-Long-Haul 400 G Transmission Systems

We experimentally assess the performance versus complexity tradeoff of advanced split-step and Volterra-based digital backpropagation (DBP) techniques, applied to aWDM (75-GHz flexigrid) ultra-long-haul (ULH) transmission system composed of five dual-carrier PM-16 quadratic-amplitude modulation 400 G superchannels. Using the recently proposed weighted Volterra series nonlinear equalizer (W-VSNE), we demonstrate a maximum reach improvement of 600 km, obtained at the expense of only six DBP steps for an entire >5000-km optical link (1000 km/step), representing a ~90% reduction on the total number of DBP steps relatively to the widely used split-step Fourier method (SSFM) implementation. The W-VSNE technique is also shown to be more accurate than the correspondent weighted SSFM (W-SSFM) algorithm when applied in medium (10-50 DBP steps) and low complexity (<;5 DBP steps) regimes. The achieved reduction of computational effort (up to 88%), together with the associated latency savings (up to 90%), demonstrates the feasibility of low complexity and efficient DBP for high-speed ULH transmission systems.

Global ROADM-Based Spectrum Equalizer in SDN Architecture for QoT Optimization at DWDM Networks

We introduce a global (end-to-end) ROADM-based spectrum equalizer algorithm running over DWDM networks on SDN architecture. Significant OSNR improvements are experimentally demonstrated for a DWDM coherent 80×112Gb/s system compared with local equalization schemes.

SDN-enabled EDFA gain adjustment cognitive methodology for dynamic optical networks

We propose and experimentally validate an SDN-enabled cognitive methodology for EDFA gain adjustment that relies on case-based reasoning. Results show OSNR improvements over time demonstrating the cognition process regardless the deployed amplifier type.

Cognitive Methodology for Optical Amplifier Gain Adjustment in Dynamic DWDM Networks

Our recently proposed cognitive methodology for optical amplifier gain adjustment, that relies on case-based reasoning, showed optical signal-to-noise ratio improvements over time demonstrating the cognition process regardless the deployed amplifier type. In this paper, we extend our preliminary analysis exploring the cognitive methodology benefits for different and larger network topologies. The obtained results show agreement between networks, demonstrating the methodology suitability regardless the network scenario.