Eduardo Magalhães

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.

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.

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.

Flexible optical transmission systems for future networking

This paper describes the path for future implementations of flexible optical transmission. The baseline discussion is divided into the transponder technical aspects and the network subsystem elements. Regarding flexible transponder, three degrees of freedom such as modulation format, symbol rate and number of channels are exploited in order to obtain rate adaptive transmitters and receivers. In addition, digital signal processing is discussed to relax the hardware resources and to enhance transmission performance. As far as the optical networking is concerned, some functionalities present in node subsystems as optical amplifiers and filters in reconfigurable optical add/drop multiplexers (ROADM) / wavelength selective switches (WSS) are optimized and implemented to support the requirements needed in software defined networks (SDN).

Equivalent circuit of a semiconductor optical amplifier chip with the bias current influence

Based on a diode-laser model, this paper presents the equivalent electrical circuit above and below the transparency condition for a chip (unpackaged) semiconductor optical amplifier. The modeling and parameters extraction were obtained as a function of the bias current, achieving good agreement between theoretical and experimental results in a wide frequency range, up to 40 GHz.

Experimental-based subsystem models for simulation of heterogeneous optical networks

This work presents and analyzes experimental-based subsystem models for Erbium doped fiber amplifiers (EDFAs) and wavelength selective switches (WSSs) under operation in a metropolitan optical network testbed. Firstly, the performance of the EDFAs and two gain control types are analyzed in a heterogeneous experimental setup with lightpaths modulated at 10G/100G/200G. Secondly, the WSS optical shape filter is experimentally characterized. Subsequently, simulation models are proposed accordingly to the experimental data obtained from the experimental setups. Results of output power and spectrum shape for both amplifiers under test showed good agreement between simulation and experiment. In addition, the optical signal-to-noise ratio (OSNR) for all channels was also analyzed and it was obtained error values bellow 1 dB, which are within an acceptable error margin. The developed sub-system models will provide greater flexibility to simulate different network scenarios and enable the development and validation of future optical network intelligence algorithms.