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Esther Le Rouzic

Bio: Esther Le Rouzic is an academic researcher from Orange S.A.. The author has contributed to research in topics: Optical burst switching & Optical performance monitoring. The author has an hindex of 13, co-authored 77 publications receiving 600 citations.


Papers
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Journal ArticleDOI
TL;DR: GNPy is validated by feeding it with data from the network controller and comparing the results to experimental measurements on mixed-fiber, Raman-amplified, multivendor scenarios over the full C-band, showing excellent accuracy in predicting both the optical signal-to-noise ratio and the generalized signal- to-no noise ratio (GSNR).
Abstract: In this paper, we describe the validation of GNPy. GNPy is an open source application that approaches the optical layer according to a disaggregated paradigm, and its core engine is a quality-of-transmission estimator for coherent wavelength division multiplexed optical networks. This software is versatile. It can be used to prepare a request for proposal/request for quotation, as an engine of a what-if analysis on the physical layer, to optimize the network configuration to maximize the channel capacity, and to investigate the capacity and performance of a deployed network. We validate GNPy by feeding it with data from the network controller and comparing the results to experimental measurements on mixed-fiber, Raman-amplified, multivendor scenarios over the full C-band. We then test transmission distances from 400 up to 4000 km, polarization-multiplexed (PM) quadrature phase shift keying, the PM-8 quadrature amplitude modulation (QAM) and PM-16QAM formats, erbium-doped fiber amplifier (EDFA) and mixed Raman–EDFA amplification, and different power levels. We show excellent accuracy in predicting both the optical signal-to-noise ratio and the generalized signal-to-noise ratio (GSNR), within 1 dB accuracy for more than 90% of the 500 experimental samples. We also demonstrate the ability to estimate the transmitted power maximizing the GSNR within 0.5 dB of accuracy.

131 citations

Journal ArticleDOI
TL;DR: This work presents an exhaustive analysis and an accurate evaluation for spectrum fragmentation issue in flexible optical networks and proposes new metric for fragmentation measurements and some approaches to address such a problem.
Abstract: Flexible grid optical networks allow an efficient utilization of spectrum resources using 12.5-GHz frequency slot multiples instead of a fixed spacing, introducing however spectrum fragmentation (SF). In the literature, SF is often assumed to be a serious problem specifically in a dynamic traffic context. It is mostly related to the bandwidth blocking ratio due to the lack of relevant comparison criteria and efficient metrics. Besides, in operator core network, traffic behavior is instead incremental and it is forecasted for short periods of time in addition to some operational constraints that make of it a specific context. In this work, we present an exhaustive analysis and an accurate evaluation for SF issue in flexible optical networks. We also propose new metric for fragmentation measurements and some approaches to address such a problem.

36 citations

Proceedings ArticleDOI
01 Sep 2012
TL;DR: It is shown that, over the equipment's lifetime, for IP/MPLS routers it is reasonable to almost double the optimal power rating value under real-life equipment filling conditions, and power measurements on IP routers and Optical Line Amplifiers show that their power consumption marginally depends on traffic load.
Abstract: Reasonably accurate reference power consumption values are required for any work that evaluates power consumption in telecommunication networks. Many existing works provide or use optimal power rating (W/Gbps) values, i.e. the power rating achieved for the maximum capacity of the system, with the shared relative overhead thus being the smallest. In this paper, we evaluate how power rating values are influenced by practical equipment filling levels for core IP-over-WDM equipment. We show that, over the equipment's lifetime, for IP/MPLS routers it is reasonable to almost double the optimal power rating value under real-life equipment filling conditions. For Optical Line Amplifiers a correction factor of 1.5 is appropriate, and for WDM terminals the required correction is almost negligible, i.e. 1.1. Furthermore, power measurements on IP routers and Optical Line Amplifiers show that their power consumption marginally depends on traffic load.

33 citations

Journal ArticleDOI
TL;DR: A practical implementation of sleep mode strategies for network operators is to define, on the basis of typical traffic trend, few configurations to be activated in specific time instants.

31 citations

Journal ArticleDOI
TL;DR: This work looks at the electrical and optical layers of IP-over-WDM networks, and presents a list of evaluation criteria for energy- aware adaptive routing solutions (EA-ARSs) from the perspective of a network operator.
Abstract: Energy saving in telecommunications networks has become a well established topic in the research community. We look at the electrical and optical layers of IP-over-WDM networks, and present a list of evaluation criteria for energy- aware adaptive routing solutions (EA-ARSs) from the perspective of a network operator. Furthermore, we briefly explain the adaptive routing solutions originating from the European Union's TREND and the FP7 Network of Excellence, show saving of energy consumed by line cards in a reference scenario, and use the evaluation criteria to identify the next steps toward introduction of the EA-ARSs into real operation.

31 citations


Cited by
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Journal ArticleDOI
TL;DR: Several important aspects of green ICN are identified, i.e., overview, energy efficiency metrics, network planning, enabling technologies, and challenges, including shutdown, slowdown, mobility, and cloud computing.
Abstract: Recently, a series of innovative information-centric networking (ICN) architectures have been designed to better address the shift from host-centric end-to-end communication to requester-driven content retrieval. With the explosive increase of mobile data traffic, the mobility issue in ICN is a growing concern and a number of approaches have been proposed to deal with the mobility problem in ICN. Despite the potential advantages of ICN in mobile wireless environments, several significant research challenges remain to be addressed before its widespread deployment, including consistent routing, local cached content discovery, energy efficiency, privacy, security and trust, and practical deployment. In this paper, we present a brief survey on some of the works that have already been done to achieve mobile ICN, and discuss some research issues and challenges. We identify several important aspects of mobile ICN: overview, mobility enabling technologies, information-centric wireless mobile networks, and research challenges.

245 citations

Journal ArticleDOI
Yvan Pointurier1
TL;DR: Techniques that the network designer can use in order to increase the capacity of optical networks, extend their life, and decrease deployment cost (CAPEX) or total cost of ownership over their life duration are reviewed.
Abstract: We review margins used in optical networks and review a formerly proposed margin taxonomy. For each category of margins, we review techniques that the network designer can use in order to increase the capacity of optical networks, extend their life, and decrease deployment cost (CAPEX) or total cost of ownership over their life duration. Green field (new network deployments) and brown field techniques (used after initial network deployment) are discussed. The technology needed to leverage the margins and achieve the aforementioned gains are also reviewed, along with the associated challenges.

226 citations

Journal ArticleDOI
TL;DR: In this paper, the potential and challenges of fiber-optic multi-band transmission (MBT) covering the ITU-T optical bands O(rightarrow$ ǫ ) were discussed.
Abstract: Fiber-optic multi-band transmission (MBT) aims at exploiting the low-loss spectral windows of single-mode fibers (SMFs) for data transport, expanding by $\sim\!11\times$ the available bandwidth of C-band line systems and by $\sim\!5\times$ C+L-band line systems’. MBT offers a high potential for cost-efficient throughput upgrades of optical networks, even in absence of available dark-fibers, as it utilizes more efficiently the existing infrastructures. This represents the main advantage compared to approaches such as multi-mode/-core fibers or spatial division multiplexing. Furthermore, the industrial trend is clear: the first commercial C $+$ L-band systems are entering the market and research has moved toward the neighboring S-band. This article discusses the potential and challenges of MBT covering the ITU-T optical bands O $\rightarrow$ L. MBT performance is assessed by addressing the generalized SNR (GSNR) including both the linear and non-linear fiber propagation effects. Non-linear fiber propagation is taken into account by computing the generated non-linear interference by using the generalized Gaussian-noise (GGN) model, which takes into account the interaction of non-linear fiber propagation with stimulated Raman scattering (SRS), and in general considers wavelength-dependent fiber parameters. For linear effects, we hypothesize typical components’ figures and discussion on components’ limitations, such as transceivers,’ amplifiers’ and filters’ are not part of this work. We focus on assessing the transmission throughput that is realistic to achieve by using feasible multi-band components without specific optimizations and implementation discussion. So, results are meant to address the potential throughput scaling by turning-on excess fiber transmission bands. As transmission fiber, we focus exclusively on the ITU-T G.652.D, since it is the most widely deployed fiber type worldwide and the mostly suitable to multi-band transmission, thanks to its ultra-wide low-loss single-mode high-dispersion spectral region. Similar analyses could be carried out for other single-mode fiber types. We estimate a total single-fiber throughput of 450 Tb/s over a distance of 50 km and 220 Tb/s over regional distances of 600 km: $\sim\!10\times$ and 8× more than C-band transmission respectively and $\sim\!2.5\times$ more than full C+L.

179 citations

Journal ArticleDOI
TL;DR: This paper proposes an energy-efficient multi-constraint rerouting algorithm, E2MR2, which uses the energy consumption model to set up the link weight for maximum energy efficiency and exploits rerouted strategy to ensure network QoS and maximum delay constraints.
Abstract: Many researches show that the power consumption of network devices of ICT is nearly 10% of total global consumption. While the redundant deployment of network equipment makes the network utilization is relatively low, which leads to a very low energy efficiency of networks. With the dynamic and high quality demands of users, how to improve network energy efficiency becomes a focus under the premise of ensuring network performance and customer service quality. For this reason, we propose an energy consumption model based on link loads, and use the network’s bit energy consumption parameter to measure the network energy efficiency. This paper is to minimize the network’s bit energy consumption parameter, and then we propose the energy-efficient minimum criticality routing algorithm, which includes energy efficiency routing and load balancing. To further improve network energy efficiency, this paper proposes an energy-efficient multi-constraint rerouting (E2MR2) algorithm. E2MR2 uses the energy consumption model to set up the link weight for maximum energy efficiency and exploits rerouting strategy to ensure network QoS and maximum delay constraints. The simulation uses synthetic traffic data in the real network topology to analyze the performance of our method. Simulation results that our approach is feasible and promising.

166 citations

Journal ArticleDOI
TL;DR: This survey paper starts with the basic concept of EONs and their unique properties, and then moves to the fragmentation problem in Eons, and evaluates and analyzes the major fragmentation management approaches in terms of blocking probability.
Abstract: Bandwidth fragmentation, a serious issue in elastic optical networks (EONs), can be suppressed by proper management in order to enhance the accommodated traffic demands. In this context, we need an in-depth survey that covers bandwidth fragmentation problems and how to suppress them. This survey paper starts with the basic concept of EONs and their unique properties. This paper then moves to the fragmentation problem in EONs. We discuss and analyze the major conventional spectrum allocation policies in terms of the fragmentation effect in a network. The taxonomies of the fragmentation management approaches are presented along with different node architectures. Subsequently, this paper reviews state-of-the-art fragmentation management approaches. Next, we evaluate and analyze the major fragmentation management approaches in terms of blocking probability. Finally, we address the research challenges and open issues on fragmentation problem in EONs that should be addressed in future research.

156 citations