Cost-effective ROADM design to maximize the traffic load capacity of u-DWDM coherent metro-access networks

The current constant growing in traffic demands caused by the popularization of cloud services, mobile and social networks is requiring architectural changes at the underlying networks so as to provide a more highly dynamic connectivity. Cost-effective and energy efficient solutions are also required in flexible network subsystems in order to make available future sustainable networks. In this context, a novel cost-effective and energy-efficient solution DWDM ROADM (D-ROADM) node design has been recently considered to enable optical Metro-Access networks convergence. In this paper, we assess the D-ROADM capabilities in a dynamic ultra-Dense Wavelength Multiplexing (u-DWDM) coherent Ring Network scenario. In particular, the metric Blocking Bandwidth Probability (BBP) vs. Traffic Load Capacity (TLC) has been considered. Our numerical evaluations show that the performance penalty of cost-effective D-ROADM based networks could be reduced to 35% for 62.5GHz DWDM channels when compared to WSS-based ROADMsPeer ReviewedPostprint (author's final draft

Experimental assessment of 10 Gbps 5G multicarrier waveforms for high-layer split U-DWDM-PON-based fronthaul

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The current constant growth in mobile networks' traffic demands caused by the popularization of cloud and streaming services on personal devices, requires architectural changes so as to fulfill all new 5G mobile network requirements. Cloud access radio network (C-RAN) architecture in combination with the massive deployment of small cell antenna sites have recently been proposed as a promising solution but will be demanding for high-capacity mobile fronthaul links. An efficient way for performing that connectivity is to make use of the dense wavelength multiplexing passive optical network (DWDM-PON) infrastructure. In this context, orthogonal frequency division multiplexing (OFDM) has been extensively explored as a potential candidate. Nevertheless, the main drawback of OFDM is its high out-of-band radiation. In order to overcome that drawback, new 5G multicarrier waveforms (FBMC, UFMC, and GFDM) have recently been proposed. In this paper, we experimentally assess and compare 10 Gbps 32-QAM-OFDM/FBMC/UFMC/GFDM system performance for high-layer split ultra-DWDM-PON-based fronthaul using a radio-over-fiber technique. The performance has been done in terms of spectral efficiency, peak-to-average power ratio, spectral density, and receiver sensitivity. In particular, intensity-modulation with direct-detection and quasi-coherent-detection have been considered. In order to improve the multicarrier system energy efficiency, the effect of using a hard clipping technique over transmitted signals is also studied. Finally, we evaluated the crosstalk interference between two adjacent channels of the same modulation scheme, as a function of their electrical frequency span for downlink application.Peer ReviewedPostprint (author's final draft

Random number generation by coherent detection of quantum phase noise

In 2010 Qi et al. [Opt. Lett. 35(3), 312 (2010)] demonstrated a random number generator based on the drift of the phase of a laser due to spontaneous emission, The out-of-the-lab implementation of this scheme presents two main drawbacks: it requires a long and highly unbalanced interferometer to generate a random phase with uniform probability distribution, or alternatively, a shorter and slightly unbalanced interferometer that notwithstanding requires active stabilization and does not generate a uniform probability distribution without randomness extraction. Here we demonstrate that making use of the random nature of the phase difference between two independent laser sources and two coherent detectors we can overcome these limitations. The two main advantages of the system demonstrated are: i) it generates a probability distribution of quantum origin which is intrinsically uniform and thus in principle needs no randomness extraction for obtaining a uniform distribution, and ii) the phase is measured with telecom equipment routinely used for high capacity coherent optical communications. The speed of random bit generation is determined by the photodetector bandwidth and the linewidth of the lasers. As a by-product of our method, we have obtained images of how phase noise develops with time in a laser. This provides a highly visual alternative way of measuring the coherence time of a laser.Peer ReviewedPostprint (published version

Cost-effective DWDM ROADM design for flexible sustainable optical metro–access networks

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksArchitectural changes are required for the underlying networks to support the expected Internet data traffic volume growth caused by the popularization of cloud services, 5G-based services, and social networks, to provide a highly dynamic connectivity. Cost-effective and energy-efficient solutions for flexible network subsystems are required to provide future sustainable networks. In this paper, we present a cost-effective dense wavelength division multiplexing (DWDM) reconfigurable optical add/drop multiplexer (ROADM) design enabling optical metro–access networks convergence. The cost-effective DWDM ROADM capabilities also have been assessed in an ultradense wavelength multiplexing (u-DWDM) ring network scenario. In particular, achievable network throughput has been considered.Peer ReviewedPostprint (published version

Split-enabled 350–630 Gb/s optical interconnect with direct detection NOMA-CAP and 7-core multi-core fiber

The ever-growing data traffic volume inside data centers caused by the popularization of cloud services and edge computing demands scalable and cost-efficient network infrastructures. With this premise, optical interconnects have recently gained more and more research attention as a key building block to ensure end-to-end energy efficient solutions, offering high throughput, low latency and reduced energy consumption compared to current networks based on active optical cables. An efficient way for performing such optical interconnects is to make use of multi-core fibers (MCFs), which enables the multiplexing of several spatial channels, each using a different core inside the same fiber cladding. Moreover, non-orthogonal multiple access combined with multi-band carrierless amplitude and phase modulation (NOMA-CAP) has been recently proposed as a potential candidate to increase the network capacity and an efficiency/flexibility resource management. In this paper, using direct detection we experimentally demonstrate the transmission of NOMA-CAP signals through a 2 km MCF with 7 spatial channels for high capacity optical interconnect applications. The results show negligible transmission penalty for different total aggregated traffics ranging from 350 Gb/s to 630 Gb/s.This work was supported in part by ALLIANCE (TEC2017-90034-C2-2-R) project co-funded by FEDER, the European Union’s Horizon 2020 research and innovation programme under grant agreement no780997 (plaCMOS), as well as MINECO FPI-BES-2015-074302Peer ReviewedPostprint (author's final draft

Cost-effective ROADM architecture for C/DWDM metro-access networks convergence

The Internet data traffic constant growth caused by the popularization of cloud services, mobile and social networks is requiring changes at the underlying networks in order to enable scalability whereas supporting a highly dynamic connectivity. Cost-effective and energy efficient solutions for flexible network subsystems are also required in order to provide future sustainable networks. In this paper, we present the design of a scalable cost-effective CWDM ROADM that can easily be upgraded to work with C/DWDM channel enabling future Metro-Access Networks convergence.Peer Reviewe

Cost-effective ROADM design to maximize the traffic load capacity of u-DWDM coherent metro-access networks

The current constant growing in traffic demands caused by the popularization of cloud services, mobile and social networks is requiring architectural changes at the underlying networks so as to provide a more highly dynamic connectivity. Cost-effective and energy efficient solutions are also required in flexible network subsystems in order to make available future sustainable networks. In this context, a novel cost-effective and energy-efficient solution DWDM ROADM (D-ROADM) node design has been recently considered to enable optical Metro-Access networks convergence. In this paper, we assess the D-ROADM capabilities in a dynamic ultra-Dense Wavelength Multiplexing (u-DWDM) coherent Ring Network scenario. In particular, the metric Blocking Bandwidth Probability (BBP) vs. Traffic Load Capacity (TLC) has been considered. Our numerical evaluations show that the performance penalty of cost-effective D-ROADM based networks could be reduced to 35% for 62.5GHz DWDM channels when compared to WSS-based ROADMsPeer Reviewe

Passive optical networks: introduction

This is the preprint version of the article “Passive Optical Networks, Introduction” by Jose Antonio Altabas, Samael Sarmiento Hernández and José Antonio Lázaro Villa, accepted for publication in Wiley Encyclopedia of Electrical and Electronics Engineering (2018). http://dx.doi.org/10.1002/047134608X.W8373Passive optical networks (PONs) are telecommunication networks that provide services to users by no active elements. Only passive elements are used in the network to transmit the information and signals between users as well as between users and the companies operating the telecommunication networks. PON have evolved from their infancy as fine and economical ideas, toward a long-term, reliable, and cost-effective technical solutions for providing access to most users to high-speed Internet by Fiber-to-the-Home (and similar) solutions. PON are still evolving, providing the base of multiple standardized networks and in combination with different technologies are growing into metropolitan networks and extensions of mobile communications. Herein, we overview the state of the art of passive optical networks as well as their basic concepts. This work is divided into four sections: In Section 1, we give a summary of the main concepts of passive optical networks. Sections 2 and 3 introduce the most important features of ITU-T Recommendations and IEEE Standards for passive access networks, respectively. Finally, Section 4 concludes the article with an overview on the future trends of PONs for access networks.Peer Reviewe

Experimental assessment of 10 Gbps 5G multicarrier waveforms for high-layer split U-DWDM-PON-based fronthaul

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The current constant growth in mobile networks' traffic demands caused by the popularization of cloud and streaming services on personal devices, requires architectural changes so as to fulfill all new 5G mobile network requirements. Cloud access radio network (C-RAN) architecture in combination with the massive deployment of small cell antenna sites have recently been proposed as a promising solution but will be demanding for high-capacity mobile fronthaul links. An efficient way for performing that connectivity is to make use of the dense wavelength multiplexing passive optical network (DWDM-PON) infrastructure. In this context, orthogonal frequency division multiplexing (OFDM) has been extensively explored as a potential candidate. Nevertheless, the main drawback of OFDM is its high out-of-band radiation. In order to overcome that drawback, new 5G multicarrier waveforms (FBMC, UFMC, and GFDM) have recently been proposed. In this paper, we experimentally assess and compare 10 Gbps 32-QAM-OFDM/FBMC/UFMC/GFDM system performance for high-layer split ultra-DWDM-PON-based fronthaul using a radio-over-fiber technique. The performance has been done in terms of spectral efficiency, peak-to-average power ratio, spectral density, and receiver sensitivity. In particular, intensity-modulation with direct-detection and quasi-coherent-detection have been considered. In order to improve the multicarrier system energy efficiency, the effect of using a hard clipping technique over transmitted signals is also studied. Finally, we evaluated the crosstalk interference between two adjacent channels of the same modulation scheme, as a function of their electrical frequency span for downlink application.Peer Reviewe

5G connected vehicles supported by optical fiber access

Future autonomous vehicle will require a high level of computation, communication, sensing and fast response actuation. Communication among vehicles, and vehicles to infrastructure, accessing to remote systems and services will help to reduce other requirements in computation and sensing. This paper revise current state of the art of wireless technologies as: LTE, LTE-A Pro, IEEE802.11p and 5G, as well as optical fiber access technologies as: TDM, WDM, D-WDM and uD-WDM, for the different communications requirements in diverse scenarios as: Vehicle-to-Infrastructure (V2I), Vehicle-to-Vehicle (V2V), Vehicle-to-Pedestrian (V2P) and Vehicle-to-Network (V2N).Peer ReviewedPostprint (published version