Stefano Straullu

Optimization of Reflective FDMA-PON Architecture to Achieve 32 Gb/s Per Upstream Wavelength Over 31 dB ODN Loss

In the framework of the EU-funded research project “FABULOUS,” we experimentally demonstrate an innovative FDMA-PON architecture whose upstream transmission is based on a reflective Mach-Zehnder modulator. By a careful optimization of electrical spectrum allocation, semiconductor optical amplifier biasing point, and modulation index, we upgrade previous results over similar architectures, significantly increasing the achievable optical distribution network loss. We demonstrate an overall upstream capacity of 32 Gb/s per wavelength over 37 km of installed fiber and 31 dB loss.

GN-Model Validation Over Seven Fiber Types in Uncompensated PM-16QAM Nyquist-WDM Links

We report on a set of transmission experiments over seven different uncompensated fiber links carrying a 22-channel Nyquist-WDM signal comb based on polarization-multiplexed 16-quadrature amplitude modulation at RS=15.625 GBd(RB=125 Gb/s). The channel spacing was Δf=16 GHz. The experimental transmission performance was compared with analytical GN-model predictions showing a good agreement for all seven considered fiber types. Moreover, we used the experimental results for the validation of a fiber figure of merit based on the maximum reach, showing its effectiveness for approximate fiber performance prediction. Within the experimental tests, a maximum transmission distance of 3810 km at a bit error-rate of 1.5×10-2 was achieved using a pure-silica-core fiber with 150 μm2 effective area, at a net spectral-efficiency-distance product of 24700 (b·km)/(s· Hz), in a good agreement with the GN-model forecast.

A New Physical Layer Capable of Record Gigabit Transmission Over 1 mm Step Index Polymer Optical Fiber

In this paper we present the latest results from the POF-PLUS EU Project, demonstrating record transmission of a Gigabit Ethernet compliant stream over 75m of 1mm PMMA SI-POF with 2.5 dB system margin, and over 50 m with 7 dB system margin, in both cases using commercial RC-LED. We believe this is an unprecedented results, showing for the first time that the target distance of 50 meters is reachable with a large system margin. The results were made possible by a careful optimization of the physical layer architecture, which is explained in detail in this paper. The system is experimentally demonstrated over realistic digital stream at the transmitter and real time processing at the receiver.

First demonstration of real-time LED-based Gigabit Ethernet transmission on 50m of A4a.2 SI-POF with significant system margin

We present the first experimental demonstration of a Gigabit Ethernet transmission system capable of reaching 50m on A4a.2 POF (standard 1mm PMMA Step-Index Plastic Optical Fiber) with high system margin (6.5 dB) under real Ethernet traffic flowing between two workstations.

Optimization of self-coherent reflective PON to achieve a new record 42 dB ODN power budget after 100 km at 1.25 Gbps

We demonstrate a greater than 42 dB optical distribution network power budget in the upstream of a 1.25 Gbps self-coherent reflective PON after 100 km of installed fibers, using off-the-shelf optoelectronic components, improving our previous result by 4 dB. We discuss all system optimizations introduced in the setup in order to reach such a result, including 8B/10B high-pass filtering and Faraday rotation at the ONU.

Single-Wavelength Downstream FDMA-PON at 32 Gbps and 34 dB ODN Loss

We propose a passive optical network (PON) solution to reach 32 Gb/s over a traditional high loss downstream splitter-based optical distribution network without using multiple wavelengths at the optical line terminal (OLT) side nor massive digital signal processing at the optical network unit side. The achieved 32 Gb/s capacity is not too far from the 40 Gb/s given by a four-wavelength time and wavelength division multiplexed-PON but completely avoids the handling of multiple wavelengths because of a higher electrical spectral efficiency and some system optimization.

Self-coherent single wavelength SC-FDMA PON uplink for NG-PON2

A realistic uplink FDMA scenario for NG-PON2 is demonstrated with low speed electronics in the ONU (500 MHz) and high per wavelength aggregate capacity (12 to 15 Gbps). Stability over field deployed fiber is proven.

Compatibility between coherent reflective burst-mode PON and TWDM-PON physical layers

We discuss the compatibility between reflective PON architectures and the recently defined ITU-T G.989.1 TWDM-PON. Focusing on the upstream, we experimentally demonstrate that, by using burst-mode coherent detection at OLT, reflective PON can achieve the specification target set for TWDM-PON, without requiring precise wavelength accuracy at ONU. Compared to the companion ECOC 2013 paper, we investigate on the differential optical path loss (DOPL) issue, proposing a simple SOA gain control algorithm to achieve reliable transmission for DOPL up to 17 dB.

Overview of the FABULOUS EU Project: Final System Performance Assessment With Discrete Components

In this paper, we present the most comprehensive system demonstrator realized so far inside the FABULOUS project, an EU 7th Framework Program European research project. The architecture proposed in FABULOUS is based on frequency division multiplexed PON and uses a self-coherent and reflective approach in the upstream. The demonstration presented in this paper uses discrete optoelectronics components. We will show system experiments realized with five active optical network units, together with the emulation of other 27 ONUs ASE noise, demonstrating that such network is capable of an upstream transmission of 32 Gb/s over 40 km of dark fiber and an attenuation of 31 dB, in compliancy with ODN class N2 of the latest PON standards. In addition, we will demonstrate, thanks to the flexibility of frequency multiplexing, that the network can adapt its performances to the link conditions, achieving higher aggregate bit rates or higher losses depending on the link quality that every user in the network experiences. To conclude, we will investigate on the feasibility of the required digital signal processing onto FPGA or ASIC platforms.

Real-time Gigabit Ethernet bidirectional transmission over a single SI-POF up to 75 meters

In this paper we demonstrate 1Gb/s bidirectional transmission over a single SI-POF, over the record distance of 75m. We successfully tested our system running real time Gigabit Ethernet traffic generated by a router tester.