88 research outputs found

    Deflection Routing Strategies for Optical Burst Switching Networks: Contemporary Affirmation of the Recent Literature

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    A promising option to raising busty interchange in system communication could be Optical Burst Switched (OBS) networks among scalable and support routing effective. The routing schemes with disputation resolution got much interest, because the OBS network is buffer less in character. Because the deflection steering can use limited optical buffering or actually no buffering thus the choice or deflection routing techniques can be critical. Within this paper we investigate the affirmation of the current literature on alternate (deflection) routing strategies accessible for OBS networks

    QoS Considerations in OBS Switched Backbone Net-Works

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    Optical Burst Switching (OBS) was proposed as a hybrid switching technology solution to handle the multi-Terabit volumes of traffic anticipated to traverse Future Generation backbone Networks. With OBS, incoming data packets are assembled into super-sized packets called data bursts and then assigned an end to end light path. Key challenging areas with regards to OBS Networks implementation are data bursts assembling and scheduling at the network ingress and core nodes respectively as they are key to minimizing subsequent losses due to contention among themselves in the core nodes. These losses are significant contributories to serious degradation in renderable QoS. The paper overviews existing methods of enhancing it at both burst and transport levels. A distributed resources control architecture is proposed together with a proposed wavelength assignment algorithm

    Performance issues in optical burst/packet switching

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    The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-01524-3_8This chapter summarises the activities on optical packet switching (OPS) and optical burst switching (OBS) carried out by the COST 291 partners in the last 4 years. It consists of an introduction, five sections with contributions on five different specific topics, and a final section dedicated to the conclusions. Each section contains an introductive state-of-the-art description of the specific topic and at least one contribution on that topic. The conclusions give some points on the current situation of the OPS/OBS paradigms

    Mécanismes de résolution et de prévention de la contention pour les réseaux optiques à commutation de rafales

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    L'explosion actuelle de l'utilisation des applications en temps réel, telles que la téléphonie et la vidéo haute définition, fait en sorte qu'une demande croissante en bande passante existe. Or, la fibre optique offre un très grand potentiel en termes de bande passante allant physiquement jusqu'à 50 terabits par seconde par fibre optique en utilisant un multiplexage en longueurs d'onde. La commutation de rafales en optique est une nouvelle technique de commutation permettant de tirer profit des avantages de la commutation de paquets et de la commutation de circuits. Une problématique majeure est le taux de perte élevé à cause du problème de la contention. Plusieurs techniques de résolution de la contention existent, notamment la déflexion et la retransmission. Dans la première partie de ce travail, on s'intéresse à combiner dynamiquement la déflexion et la retransmission d'une manière adaptative en tenant compte de l'état du réseau. L'algorithme proposé permet d'effectuer le plus de déflexions possibles tant que celles-ci ne déstabilisent pas le réseau. Les résultats démontrent également, avec des topologies fortement connectées telles que COST239, que l'algorithme proposé permet de diminuer radicalement les pertes en utilisant un ratio de déflexion très grand. La deuxième partie de ce travail porte sur la prévention de la contention en utilisant des tables de routage optimisées. Ces tables de routage sont optimisées en utilisant un modèle graphique probabiliste utilisé en intelligence artificielle, soit un réseau bayésien. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Fibre optique, WDM, Commutation de rafales, Contention, Déflexion, Retransmission

    Artificial intelligence (AI) methods in optical networks: A comprehensive survey

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    Producción CientíficaArtificial intelligence (AI) is an extensive scientific discipline which enables computer systems to solve problems by emulating complex biological processes such as learning, reasoning and self-correction. This paper presents a comprehensive review of the application of AI techniques for improving performance of optical communication systems and networks. The use of AI-based techniques is first studied in applications related to optical transmission, ranging from the characterization and operation of network components to performance monitoring, mitigation of nonlinearities, and quality of transmission estimation. Then, applications related to optical network control and management are also reviewed, including topics like optical network planning and operation in both transport and access networks. Finally, the paper also presents a summary of opportunities and challenges in optical networking where AI is expected to play a key role in the near future.Ministerio de Economía, Industria y Competitividad (Project EC2014-53071-C3-2-P, TEC2015-71932-REDT

    Contribution to Proving Absolute QoS in OBS Networks

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    This Final Master Project introduces a new strategy to provide QoS in IP/OBS networks, using routing with prioritization based on statistics, named RPBS. A new method is provided and subsequently validated. This proposal uses the feedback scheme in optical networks to provide statistical knowledge with the objective of finding a suitable route to reach each destination from a specific source node, with more chance of success. This yields a twofold outcome. First, the losses can be reduced in a big number due to statistics. Second, the delays are also reduced compared with other methods based on feedback scheme. These two improvements allow better QoS provision, supporting class differentiation and more efficient resources utilization. The benefits of this proposal are quantified and further compared against existent alternatives by simulations
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