scholarly journals Programmable Adaptive S-BVTs for Future Optical Metro Networks Adopting SOA-Based Switching Nodes

2018 ◽  
Author(s):  
Laura Martín González ◽  
Sjoerd van der Heide ◽  
Xuwei Xue ◽  
John van Weerdenburg ◽  
Nicola Calabretta ◽  
...  
Keyword(s):  
Optical Networks ◽  
Direct Detection ◽  
Digital Signal ◽  
Cost Effective ◽  
Optical Amplifier ◽  
Limiting Factor ◽  
Bit Rate ◽  
Discrete Multitone ◽  
Key Factor ◽  
Metro Networks

Adaptive Sliceable-Bandwidth Variable Transceivers (S-BVTs) are key enabler 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 this 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 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 S-BVT and SOA technology at the switching nodes, resulting in a promising approach for designing future optical metro networks.

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

Photonics ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 24 ◽  
Author(s):  
Laura Martín González ◽  
Sjoerd van der Heide ◽  
Xuwei Xue ◽  
John van Weerdenburg ◽  
Nicola Calabretta ◽  
...  
Keyword(s):  
Optical Networks ◽  
Direct Detection ◽  
Digital Signal ◽  
Cost Effective ◽  
Optical Amplifier ◽  
Limiting Factor ◽  
Bit Rate ◽  
Discrete Multitone ◽  
Key Factor ◽  
Metro Networks

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.

scholarly journals Optical Power Budget of 25+ Gbps IM/DD PON with Digital Signal Post-Equalization

2020 ◽  
Vol 10 (17) ◽  
pp. 6106
Author(s):  
Aleksejs Udalcovs ◽  
Toms Salgals ◽  
Lu Zhang ◽  
Xiaodan Pang ◽  
Anders Djupsjöbacka ◽  
...  
Keyword(s):  
Optical Networks ◽  
Direct Detection ◽  
Optical Power ◽  
Digital Signal ◽  
Single Mode ◽  
Pulse Amplitude ◽  
Power Splitting ◽  
Power Budget ◽  
Sustainable Solutions ◽  
The Impact

While infrastructure providers are expanding their portfolio to offer sustainable solutions for beyond 10 Gbps in the access segment of optical networks, we experimentally compare several modulation format alternatives for future passive optical networks (PONs) aiming to deliver 25+ Gbps net-rates. As promising candidates, we consider the intensity modulation direct detection (IM/DD) schemes such as electrical duobinary (EDB) and 4-level and 8-level pulse amplitude modulations (PAM-4/8). They are more spectrally efficient than the conventional non-return-to-zero on-off-keying (NRZ-OOK) used in current 10G PONs. As we move to higher rates, digital equalization enhances the performance by smoothening the systems imperfection. However, the impact that such equalization has on the optical power budget remains unclear. Therefore, in this article, we fairly compare the optical power budget values of a time division multiplexed PON (TDM-PON) exploiting a linear digital signal equalization at the receiver side. We consider the conventional PON configuration (20 km of single-mode fiber (SMF), 1:N optical power splitting) with IM/DD and net-rates above 25 Gbps. Furthermore, we focus on a downstream transmission imposing the bandwidth limitations of 10G components using a digital filter before the detection. The obtained results show that the use of a digital post-equalization with 43 feed-forward (FF) and 21 feedback (FB) taps can significantly improve the signal quality enabling new alternatives and enhancing the optical power budget.

scholarly journals A Review of DSP-Based Enabling Technologies for Cloud Access Networks

2018 ◽  
Vol 10 (11) ◽  
pp. 109
Author(s):  
Roger Giddings ◽  
Xiao Duan ◽  
Ehab Al-Rawachy ◽  
Mingzhi Mao
Keyword(s):  
Optical Networks ◽  
Research Work ◽  
Digital Signal ◽  
Cost Effective ◽  
Video On Demand ◽  
Access Networks ◽  
Mobile Systems ◽  
Data Networks ◽  
Network Resources ◽  
Optical Channels

Optical access networks, metro networks and mobile data networks are facing rapidly evolving demands, not only is it essential to satisfy the unyielding need for increased user bandwidths, but future networks must also support the growing wide variation in traffic dynamics and characteristics, due to various emerging technologies, such as cloud-based services, the Internet-of-Things (IoT) and 5G mobile systems, and due to growing trends, such as the proliferation of mobile devices and the rapidly increasing popularity of video-on-demand services. To be cost-effective and commercially sustainable, future optical networks must offer features, such as, dynamic reconfigurability, highly efficient use of network resources, elastic bandwidth provisioning with fine granularity, network sliceabilty and software defined networking (SDN). To meet these requirements Cloud Access Networks (CANs) are proposed which require a number of flexible, adaptive and reconfigurable networking elements. By exploiting digital signal processing (DSP) we have proposed a digital orthogonal filter-based multiplexing technique to implement CANs with multiplexed, independent optical channels at the wavelength, sub-wavelength, and orthogonal sub-band levels. This paper reviews the overall CAN concept, the operating principles of the various CAN network elements and presents an overview of the research work we have undertaken in order to validate the feasibility of the proposed technologies which includes real-time DSP-based demonstrations.

scholarly journals Optical Networks for Optimized and cost effective Performance

2019 ◽  
Vol 8 (9S) ◽  
pp. 944-947
Keyword(s):  
Optical Networks ◽  
Access Network ◽  
Cost Effective ◽  
Optical Amplifier ◽  
Access Networks ◽  
Passive Components ◽  
System Architectures ◽  
Modulation Format ◽  
Effective Performance ◽  
Intensive Investigation

Recently there is rapid increase of multimedia applications in the access networks. The focus of this paper is to suggest a novel system architecture that can provide efficient and cost effective solutions for the access networks. To offer economical solutions with higher bandwidth optical networks are designed with passive components. In the presented system, 512 subscribers can access information for aggregated system line rate of 80Gbps. Proposed frameworks are subjected to intensive investigation in terms of Modulation Format, External Modulator, Photo Detector so that system architectures perform at an optimized level. Also, the access network is designed without the use of reach extender devices like optical amplifier or repeater so that installation and the recurring cost are minimized.

scholarly journals Histogram Based Clustering for Nonlinear Compensation in Long Reach Coherent Passive Optical Networks

2019 ◽  
Vol 10 (1) ◽  
pp. 152 ◽  
Author(s):  
Ivan Aldaya ◽  
Elias Giacoumidis ◽  
Geraldo de Oliveira ◽  
Jinlong Wei ◽  
Julián Leonel Pita ◽  
...  
Keyword(s):  
Maximum Likelihood ◽  
Optical Networks ◽  
High Speed ◽  
Clustering Algorithm ◽  
Single Channel ◽  
Direct Detection ◽  
Digital Signal ◽  
Passive Optical Networks ◽  
Spatial Density ◽  
Signal Processors

In order to meet the increasing capacity requirements, network operators are extending their optical infrastructure closer to the end-user while making more efficient use of the resources. In this context, long reach passive optical networks (LR-PONs) are attracting increasing attention.Coherent LR-PONs based on high speed digital signal processors represent a high potential alternative because, alongside with the inherent mixing gain and the possibility of amplitude and phase diversity formats, they pave the way to compensate linear impairments in a more efficient way than in traditional direct detection systems. The performance of coherent LR-PONs is then limited by the combined effect of noise and nonlinear distortion. The noise is particularly critical in single channel systems where, in addition to the the elevated fibre loss, the splitting losses should be considered. In such systems, Kerr induced self-phase modulation emerges as the main limitation to the maximum capacity. In this work, we propose a novel clustering algorithm, denominated histogram based clustering (HBC), that employs the spatial density of the points of a 2D histogram to identify the borders of high density areas to classify nonlinearly distorted noisy constellations. Simulation results reveal that for a 100 km long LR-PON with a 1:64 splitting ratio, at optimum power levels, HBC presents a Q-factor 0.57 dB higher than maximum likelihood and 0.21 dB higher than k-means. In terms of nonlinear tolerance, at a BER of 2×10 − 3 , our method achieves a gain of ∼2.5 dB and ∼1.25 dB over maximum likelihood and k-means, respectively. Numerical results also show that the proposed method can operate over blocks as small as 2500 symbols.

Optimum placement of a fiber-optical amplifier in high-bit-rate direct-detection systems

1991 ◽  
Vol 30 (30) ◽  
pp. 4376 ◽  
Author(s):  
Thomas Rasmussen ◽  
Anders Bjarklev ◽  
Bo Pedersen ◽  
Jørn Hedegaard Povlsen
Keyword(s):  
Direct Detection ◽  
Optical Amplifier ◽  
Bit Rate ◽  
Detection Systems ◽  
Optimum Placement ◽  
Fiber Optical ◽  
High Bit Rate

scholarly journals Pitfalls in the Immunochemical Determination of β‑Lactam Antibiotics in Water

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 298
Author(s):  
Alexander Ecke ◽  
Rudolf J. Schneider
Keyword(s):  
Limit Of Detection ◽  
Cost Effective ◽  
Enzyme Linked Immunosorbent Assay ◽  
Degree Of Hydrolysis ◽  
Site Analysis ◽  
Antibody Recognition ◽  
Immunochemical Determination ◽  
Key Factor ◽  
Lactam Ring

Contamination of waters with pharmaceuticals is an alarming problem as it may support the evolution of antimicrobial resistance. Therefore, fast and cost-effective analytical methods for potential on-site analysis are desired in order to control the water quality and assure the safety of its use as a source of drinking water. Antibody-based methods, such as the enzyme-linked immunosorbent assay (ELISA), can be helpful in this regard but can also have certain pitfalls in store, depending on the analyte. As shown here for the class of β-lactam antibiotics, hydrolysis of the β‑lactam ring is a key factor in the immunochemical analysis as it influences antibody recognition. With the antibody used in this study, the limit of detection (LOD) in the immunoassay could be significantly reduced by hydrolysis for the five tested penicillins, with the lowest LOD for carbenicillin (0.2 nmol/L) and the greatest impact on penicillins G and V (reduction by 85%). In addition to enhanced quantification, our strategy also provides access to information about the degree of hydrolysis in water samples as shown for the most abundant penicillin amoxicillin.

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