Programmable Adaptive BVT for Future Optical Metro Networks Adopting SOA-Based Switching Nodes

Laura Martín González,Chigo Okonkwo,Sjoerd Van Der Heide,Xuwei Xue,Michela Svaluto Moreolo,John Van Weerdenburg,Nicola Calabretta,Josep Fàbrega

doi:10.3390/photonics5030024

Abstract

Adaptive Sliceable-Bandwidth Variable Transceivers (S-BVTs) are key enablers for future optical networks. In particular, those based on Discrete MultiTone (DMT) modulation and Direct Detection (DD) can be considered a flexible solution suitable to address the cost efficiency requirement of optical metro networks. In this paper, we propose to use a cost-effective S-BVT option/implementation in optical metro networks adopting switching nodes based on Semiconductor Optical Amplifier (SOA) technology. Bit loading (BL) and power loading (PL) algorithms are applied to the Digital Signal Processing (DSP) modules, to maximize the performance and/or the capacity as well as enhance the flexibility and adaptability of the system. Our analysis considers switching nodes based on SOAs with and without filtering elements and fiber spans of 25 km. We present the results up to 100 km, with and without SOA-based nodes. Firstly, we analyze the adaptive BVT transmission using the Margin Adaptive (MA) BL/PL algorithm at a fixed bit rate of 28 Gb/s. The possibility of controlling the SOAs current is a key factor to face the transmission impairments due to the fiber and the filtering elements. We also analyze the system considering Rate Adaptive (RA) transmission at a fixed target Bit Error Rate (BER) of 3.8 × 10−3, showing that a maximum capacity above 34 Gb/s can be achieved for a single span of 25 km. Although the cascading of filtering elements still constitutes a limiting factor, we show that an improvement of the net bit rate performance can be obtained thanks to the combined use of BVT and SOA technology at the switching nodes, resulting in a promising approach for designing future optical metro networks.

Highlights

New challenges are envisioned for future optical networks to cope with the exponential and uncertain growth of internet traffic
The current injected into the Semiconductor Optical Amplifier (SOA) is properly varied span of fiber and compare the results with the transmission over the fiber link without them
To analyze the second scenario, we consider SOA-based switching nodes based on the Optical Add/Drop (OAD) node architecture of Figure 2

Summary

Introduction

New challenges are envisioned for future optical networks to cope with the exponential and uncertain growth of internet traffic. Filterless optical networks are simple network architectures based on passive splitters and combiners avoiding optical filters They are more cost-effective than networks adopting filters; some functionalities are limited, such as wavelength reuse or capacity at high utilization rates [8,15]. We propose a combined use of BVT and SOA technologies to design flexible and cost-effective solutions for future optical metro networks. We will present preliminary results on the use of BVT in the context of elastic optical metro networks with switching nodes based on SOA technology, analyzing the case of a cost-effective implementation of the BVT.

S-BVT Architectures Tailored for Optical Metro Networks

SOA for Optical

Results and Discussion

Achievable

Conclusions