Mounia Lourdiane

Pulsed laser source coherence time impairments in a direct detection DS-OCDMA system

We investigate the impact of laser source coherence time on bit error rate (BER) and autocorrelation function performances of a direct sequence OCDMA system. Congruence codes are suggested to reduce the observed coherence effects.

Dynamic mitigation of EDFA power excursions with machine learning

Dynamic optical networking has promising potential to support the rapidly changing traffic demands in metro and long-haul networks. However, the improvement in dynamicity is hindered by wavelength-dependent power excursions in gain-controlled erbium doped fiber amplifiers (EDFA) when channels change rapidly. We introduce a general approach that leverages machine learning (ML) to characterize and mitigate the power excursions of EDFA systems with different equipment and scales. An ML engine is developed and experimentally validated to show accurate predictions of the power dynamics in cascaded EDFAs. Recommended channel provisioning based on the ML predictions achieves within 1% error of the lowest possible power excursion over 94% of the time. We also showcase significant mitigation of EDFA power excursions in super-channel provisioning when compared to the first-fit wavelength assignment algorithm.

Investigation of a hybrid optical-electronic switch supporting different service classes

Optical fiber is considered the most competitive wired transmission support thanks to its low attenuation, wide optical bandwidth, long reach, and low cost. However, optics do not yet perform higher functionalities such as switching. In fact, all-optical switches face a contention issue, due to the lack of practical optical buffers. Thus, the switching function is still performed electronically, which requires energetically costly optical-to-electronic conversions. The energy consumption is a critical issue within the growing data traffic. Thus, a proposition of hybrid switch architecture supplementing optical switch with an electronic buffer. In this paper, we propose to investigate the performance of hybrid switch that supports different priority classes where the priority is defined in terms of Packet Loss Ratio (PLR). We show that the hybrid switch is a good trade off since it allows significant performance improvements towards a buffer-less all optical switch in terms of PLR and sustainable load, for relatively few electronic ports of the buffer, which would reduce energy consumption compared to an electronic switch.

Comparison between interchangeable and WDM channels for hybrid optoelectronic switch

Taking into account different packets priorities, we investigate the performance of a hybrid opto-electronic switch where the connected azimuths support WDM channels. A comparison is given with the case of interchangeable channels, which leads us to raise the question on the limits of optical switches.

Performance improvements of hybrid opto-electronic packet switch using SDM in addition to WDM

We investigate the performance improvements of a hybrid opto-electronic switch thanks to the interchangeability provided by the use of SDM in addition to WDM in the connected links.

Performance of a 1 Gbps optical direct sequence CDMA based on sampled fiber Bragg grating

This paper presents the experimental demonstration of a 1 Gbps Direct Sequence Optical Code Division Multiple Access (DS-OCDMA) system using pulsed coherent source. Encoding and decoding using Prime Sequence codes are achieved by Sampled Fiber Bragg Gratings (S-FBGs). The encoders/decoders have been designed with OptiGrating software and realized with Phase Mask Process. BER measurements have been performed in the asynchronous configuration when an interferer is delayed from the desired signal. A 2 dB penalty due to Multiple Access Interference effect (MAI) has been observed in the synchronous case. S-FBG technological limitations and optical interferences due to the source coherence time have been observed and will be discussed.

Direct-sequence code division multiple access: From radio communications to optical networks

A direct sequence optical code division multiple access technique is investigated. This paper introduces, first, the principles definitions of Code Division Multiple Access in radio communications. After that, the performances of Optical Code Division Multiple Access are evaluated in association with a realistic amplified optical channel model.To determine the performances obtained by this combination, different detection methods are investigated in an OpticalCDMA system. Threshold and multi-user detections are developed in association with Optical Orthogonal Codes:ooc and Prime Sequences:ps, specially designed to be adapted to fiber optic channel.RésuméDans cet article, une étude des techniques d’accès multiple par répartition de code (CDMA) à séquences directes est réalisée. En premier lieu, les principales définitions duCDMA utilisé dans les systèmes de radio communications sont données. Par la suite, les performances duCDMA optique sont évaluées en y associant un modèle réaliste de canal optique amplifié.Afin de déterminer les performances obtenues par ce modèle, différentes méthodes de détection ont été mises en œuvre dans le systèmeCDMA optique, citons comme exemple le détecteur à seuil et le détecteur multi-utilisateur. De plus des codes spécifiques auCDMA optique sont évalués et associés à notre modèle de canal, parmi lesquelles les code optiques orthogonaux (ooc) et les séquences premières (ps).

WDM slot sharing of colored optical packets for latency improvement and Class of Service differentiation

The optical packet switching technology has been identified as a key technology to offer data rate and modulation format transparency, fine switching granularity and efficient bandwidth utilization. The ANR N-GREEN project proposes a novel over-dimensioned switch/router node with colored optical packet concept. In this work, we propose a new WDM slot sharing approach that significantly improves N-GREEN node-level latency, and show that it is quite effective for Class of Service differentiation in the optical domain.

Recent advances in optical and hybrid packet switching

The future of Internet depends on meeting ever-increasing capacity needs while curbing the energy consumptions uncontrolled growth in data networks, especially in switching. Optics has a tremendous potential to solve these challenges, but the lack of practical optical buffers leaves optical packet switches vulnerable to contention, hindering their use even at moderate network loads. Recent developments in optical switching devices (InP- and silicon-based), hybrid packet switching (using electronic buffers in optical switches) and network architectures (where upper layers could tolerate some loss in the optical packet layer) show a possibility that optical packet switches are poised to make a comeback in practical networks.

Investigation of hybrid opto-electronic packet switch connected to SDM fibers considering various traffic distributions

Performance analysis of an opto-electronic packet switch using combined SDM and WDM are presented. The simulations consider a switch connected to 7-core fibers. We point out the benefits of this configuration in various traffic distributions in terms of sustainable load, latency and energy savings for several packet classes.