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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Návrh nových laboratorních úloh s gigabitovou pasivní optickou sítí / Design of new laboratory exercises with gigabit passive optical network

Chlápek, Jan January 2019 (has links)
The diploma thesis is focused on design of new laboratory exercises on the topic of gigabit passive optical networks. The theoretical analysis is devoted to acquaintance with basic problematics of PON and analysis of individual PON standards. Special attention, besides GPON, XG-PON and EPON standards, is devoted to security issues in PON. The goal of practical section of the thesis is the design of four laboratory exercises. Two exercises are focused on configuring GPON and XG-PON networks in a console environment with the help of exemplary console commands. The goal of the third exercise is to hook up and configure an EPON network using web configuration interface. The fourth exercise is designed for a realization of DoS attack against a fully functioning laboratory GPON network. The objective is to jam the upstream communication bandwidth with laser transmission causing a desynchronization between active network elements.
2

Bezpečnostní rizika v pasivních optických sítích / Security Risks in Passive Optical Networks

Šimoník, Jan January 2018 (has links)
This diploma thesis deals with the historical development of passive optical networks, according to the standards that was defined by International Telecommunication Union (APON, BPON, GPON, XG-PON and NG-PON). Further, the thesis describes the security of passive optical networks, but also a security threats which the deployment and use of passive optical technology carry. In the introductory chapters of this thesis the passive optical networks are described. The following is a description of the standards of passive optical networks in terms of their historical development. The next part is dedicated to the security of passive optical networks and possible security threats. In conclusion a description of the practical part of this thesis is given -- rack assembly, which will serve for future testing. The basic configuration of the optical line terminations that are fitted in the rack is also described. The last part of this diploma thesis is dedicated to the testing of selected security risks, which was described in the theoretical part of this thesis.
3

Vliv dynamického přidělování šířky pásma na koncové jednotky / Influence of Dynamic Bandwidth Allocation over Optical Network Unit

Sikora, Pavel January 2018 (has links)
This thesis deals with DBA algorithms used in XG-PON networks. It describes reference appearance of the DBA algorithm, as well as, three specific DBA algorithms discussed in professional articles. Particularly speaking about GIANT, HYRA and modified Max-Min Fair DBA. The thesis provides description of frames utilized by DBA algorithms in XG-PON networks, specifically XGEM frame and XGTC frames. The thesis also presents a simulation tester of DBA algorithms tested on a virtual XG-PON network. Finally, it contains the results of testing these DBA algorithms with a description.
4

Vliv velikosti rámce na dělicí poměr v pasivních optických sítích XG-PON / Influence of the frame size on splitting ratio in the passive optical networks XG-PON

Kočí, Lukáš January 2015 (has links)
The diploma thesis deals with the theoretical definition of passive optical networks, furthermore the description of methods of channel bundling in passive optical networks and the coexistence and migration between standards. The main essence of this work is the XG-PON (10-Gigabit-capable Passive Optical Network) standard. This standard is generally defined along with a description of the physical layer. The transport layer is detailed analysis. There is a description of conditions, under which the Optical Network Unit pass through, when is activated. Additionally, this diploma thesis focuses on the processes of connecting Optical Network Units to the Passive Optical Networks and the timing relationships between Optical Network Units and Optical Line Terminal. The simulations demonstrate that as the number of simultaneous connections to Optical Network Unit increase, longer wait time for each additional connection becomes. This also solves the collision conditions, that might arise in communication and the equalization delay. Finally, the diploma thesis deals with the influence of a refractive index on timing relationships.
5

Introduction des technologies de multiplexage en longueur d'onde dense dans les futures générations de réseaux d'accès optique / Dense wavelength division multiplexing technologies introduction in futures optical access networks generations

Simon, Gaël 01 December 2016 (has links)
Initialement poussées par le marché résidentiel, les évolutions du réseau d’accès optique sont aujourd’hui également stimulées par l’expansion du réseau mobile. Comme le montre le premier chapitre de ce document, l’introduction d’un multiplexage en longueur d’onde dense constitue l’une des solutions privilégiées pour permettre la montée en débit dans les réseaux d’accès optique. Dans cette thèse, l’impact de l’introduction du multiplexage en longueur d’onde dense est étudié sous trois axes :• Une prochaine étape de l’évolution des technologies pour les réseaux d’accès passerait par une hybridation entre d’une part, un multiplexage temporel (hérité des précédentes générations), et d’autre part, un multiplexage en longueur d’onde dense. Cette technologie, appelée NGPON2-TWDM, permet aujourd’hui d’envisager des débits de 40Gb/s à 80Gb/s grâce à 4 ou 8 canaux. Les difficultés liées à la stabilité de la longueur d’onde lors de l’émission de données en mode paquet dans le sens montant du lien, ainsi que les solutions associées, sont étudiées dans le second chapitre.• L’importance du marché que représente le réseau d’accès optique (aussi bien pour les clients résidentiels que pour les réseaux mobiles), induit la nécessité pour les différentes générations de technologies de coexister au sein d’une même infrastructure. Du fait des fortes puissances optiques en jeu et des plages spectrales allouées à chaque technologie, cette coexistence peut induire des interactions entre technologies par émission Raman stimulée, dont le principe et les impacts sont décrits dans le troisième chapitre.• Enfin, la quatrième partie de ce document est dédiée à l’étude des limites et potentialités de la technologie self-seeded pour le multiplexage en longueur d’onde dense en bande O, capable de stabiliser automatiquement et passivement la longueur d’onde d’émission de chacun des émetteurs du système. / Initially led by the residential market, today’s optical access network evolutions are stimulated by mobile network expansion. As shown in the first chapter of this document, dense wavelength division multiplexing is one of the favorite solutions in order to increase optical access networks throughput. In this thesis, we propose a study of dense wavelength division multiplexing introduction according to three main topics :• Service providers and equipment suppliers have decided that the next step in residential market evolution will consist in a hybridization between, on one hand, a legacy time division multiplexing, and on the other hand, a dense wavelength division multiplexing. Named NG-PON2, this technology allows today 40Gb/s to 80Gb/s thanks to 4 to 8 channel pairs. Wavelength stability of the upstream emitter under burst mode operation, and related solutions, are studied in the second chapter.• Market importance (for both residential market and mobile networks) requires the different technologies generations to coexist on the same infrastructure. Due to the high optical power and the wavelength spans allocated to each technology, this coexistence can lead to technologies interactions by stimulated Raman scattering, as described in the third chapter.• Finally, the fourth part of this document describes the limits and potentialities of the self-seeded emitter technology for O-band dense wavelength division multiplexing, able to automatically and passively self-stabilize the wavelength of each emitter.

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