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Quality of Services in Optical Access Networks
Šifta, Radim ; Křepelka, Václav (referee) ; Vlček, Čestmír (referee) ; Filka, Miloslav (advisor)
The thesis focuses on the optical access networks and deals with the issue of transmission parameters of the physical layer, their negative impact on the quality of the services parameters and the possibilities of reducing their effect using the polarization multiplexing. The first and second chapter describe the theoretical background necessary for understanding the subsequent parts. The third chapter contains the practical part of the thesis. At first the optical routes in the Czech Republic in terms of polarization mode dispersion, which is together with insertion loss the main limiting parameter of high-speed optical networks, are evaluated. In the following part the measuring of the temperature changes effects on the polarization mode dispersion of the passive components and the effect of temperature changes to the polarization multiplexed signal are evaluated. To double the bandwidth and reduce the influence of polarization mode dispersion on the quality of services, the two simulation models of optical access networks using polarization multiplexing were carried out. These theoretical outputs were verified by the practical measurements in the laboratory and subsequently on the real optical route. Finally, a draft of the broadband optical access network based on wavelength and polarization multiplexing was designed based on obtained knowledge.
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Assemblying effect on cable lines quality
Dočkal, Martin ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
In the first part is explained what actually a structured cabling is. Its beginning, from what and why it was created. Its history when at the beginning were applied unbalanced coaxial cables, those were later replaced by balanced cables. In cabling for TVs are still used coaxial cables. Balanced cables are according to type named UTP, STP, FTP, and so on. Whit growing popularity of this type of cabling and its wide spread application was necessary to set some rules, standards, specifications and demands, how to build up the cabling from project to realization. According to these rules is the system built so there are strict rules for length of subsystems and interfaces and the whole appearance of the structure cabling. Next important point is projecting of cabling that is related to the previous points and when it’s finished, we should strictly follow it. With the project is closely connected characteristic of this cabling as attenuations, cross-talks and other transmission parameters which are measured in the practical part. In the second part is spoken about all the parts of which the structured cabling consists - metallic and optical connecting elements and cables. There are also mentioned their mechanical, electrical and transmission features. In the third part is described influence of man on the quality of structured cabling and the most common causes of lower quality and the ways how to prevent this from happening and how to manipulate with cabling not to destroy it. The final (fourth) part considers the measurement. There are measured qualities of metallic wires as the attenuations, delay, cross-talks on the near- and far-end, impedance and resistance. To all the features are mentioned schemes of the measurement on the twisted pairs. The measurement is divided into two parts. In the first part are measured five types of balanced cables of different length, category and damage influencing quality of these cables. In the second part is measured one balanced cable if it’s corresponding with category 5 for that t was made and if it would be possible to use it also for higher category 6. Values are tabularly sorted in tables.
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The Design of FTTH Network
Zorgani, Nagib Youssef ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The aim of this thesis is to explain the problems of optical access networks with wavelength division multiplexers, main purpose is to demonstrate the difference between theoretical and real measurement. The work is divided into several thematic areas. The introduction outlines the basic of telecommunications, fiber optics lasers, single mode, multimode, lasers fibers cables & cores, splitters division multiplexing system, there are known solutions discussed fundamental wavelength multiplexes and their possible combinations. The following chapter deals with the active elements such as AON, PON, which are essential part xWDM systems such as optical lasers, detectors and amplifiers. Another chapter focuses on passive elements, which form a key part of the wavelength multiplex. Methods of measurement of WDM/PON networks are discussed in the following part. The next section describes the topology used active and passive optical networks. The penultimate part of the work consists of architecture & technology of xWDM such as GPON and WDM-PON networks and comparing their transmission parameters. The final part of the paper presents the results of practical experimental measurements of optical access networks with wavelengths division multiplex while these results are compared with the theoretical output & methods of Optical lost test, OTDR & LSPM, with advantage & disadvantage of every methods. The second part of practical is the draft to the connection resident housing units of 30 houses, boarding-house (10 rooms) and 2 shops, 20 km distant from exchange. With comparing the possibilities of two options- passive and active optical network- PON system – WDM- Wave multiplex. Suggest the possibility of measuring and monitoring the created network.
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POF - polymer optical fibres
Mikulec, Matěj ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
This work focuses on polymer optical fiber (POF). It describes basic properties of polymer optical fibers, materials for production and methods of manufacturing processes. In following chapters are given individual fibers that vary different refractive indexes and diameter of fiber. Also there are analyse connectors which are used for joining. As very suitable solution for home installation seems to be using the system Optolock without connectors. In the work is also written several areas where it is possible to use the POF. It can break through in automotive industry, home networks or as a sensor. The practical part contains measuring polygon draft and FTTH proposal using POF for distribution system in the house, where P2P topology is choosen. It´s also made a proposal for distribution of POF in the apartment. For installation in the apartment prices of network components are compared between POF distribution and UTP cat.6 cabling. UTP cat.6 is in this comparison many times more cheaply. Final chapter evaluate demands on work with POF fibers. Describes preparation of fiber before communication and creation of small experimental network. Important findings of the work are summarized in the conclusion.
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Methodology for designing PON networks
Dallal, Anas Omar ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
Cílem této práce je analyzovat současný stav přístupových optických sítí,a hlouběji prozkoumat PON metodiku a návrh sítě. Navrhnul jsem síť založenou na konceptu FTTH pro 90 rodinných domů ovládané z centrální stanice vzdálené 20 km. Zabýval jsem se problémy při návrhu FTTH, konkrétně pasivní optickou sítí. Dále jsem se zabýval ATM-PON a Ethernet PON (EPON), které jsou založeny na společné síťové architektuře, PON, ale používají jiné přenosové technologie na podporu integrovaných služeb a jiné protokoly. Po zadání (optimálního) síťového řešení, které se hodí pro nabídku Triple-Play služeb. Dále budu popisovat, jak fungují síťová propojení a také budou popsány metody měření a testování navržené sítě "po aktivaci a nastavení sítě" a "před aktivací síťových služeb ". Při měření jsem také používal OTDR a prakticky ověřil charakteristiku linky. V práci je také naznačeno monitorování optické sítě.
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Optical Amplifiers
Mlejnek, Zbyněk ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
Optical amplifiers has sparked a revolution in the telecommunications industry during th last ten years. Optical amplifiers are devices that amplifies an optical signal directly, without the need to first convert it to an electrical signal. Its ability to provide low-noise amplification over a range of wavelengths, fortuitously correspoding to the low-loss of silica fiber, has made optical networks economically attractive
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Spectral characteristics measurement of single fibre optical transmission
Balon, Radek ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The main object of the bachelor´s thesis is show familiarize with optical networks and measuring when the fibres are connected to operating network. The whole thesis was separated into several parts. The first part was deals with optic fiber and properties, kinds of optic fibers, methods of propagation light inside fiber and important parameters, which has undesirable effects, such as optic loss and dispesive influences. Next part was concentrated on transfer technologies, which where used for data transmission in operating networks. We talked about differences between technologies and describe the monitoring system, which was used for measuring parameters in operating network. The last part was focused on own measuring. We was measured the parameters in operating network CESNET2 and influence of the signal after connect optic monitoring probe. Measuring was implemented on optical network of Masaryk University in Brno (ÚVT MU).
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QoS implementation in access network
Hauser, Václav ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
My bachelor thesis deals with the implementation of quality of service in the access network. My bachelor thesis describes at first the concept of quality of service and its characteristics. In addition, it makes the reader familiar with various implementations models. At first with integrated services, which are based on the RSVP reservation protocol. The task of this protocol is to establish the route through the reserve RESV and PATH messages. The second implementation model contains the differentiated services. There is no reservation protocol, quality of service is ensured by using the classification of individual data flows. Accordingly, as packets are classified, they are assigned according to a priority, which is crucial for the packets travel through the network. Next part of this thesis describes the implementation of any different types of configuration of two implementation models of quality of services. There is configuration of RSVP protocol, MQC, AutoQos and MLS QoS. Final chapter describes the configurations examples.
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The quality of assembly in data transmission
Šalplachta, Milan ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The content of this work is theoretical and practical an analysis of transmission characteristics of structured cabling and related effect of assembling, which directly affects the characteristics of channel. Individual treshold limits of channel parametres, as technological methods of montages are outgoing from corresponding european specifications.
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Laboratory Monitoring System
Bošeľa, Jaroslav ; Křepelka, Václav (referee) ; Škorpil, Vladislav (advisor)
This bachelor thesis deals with network monitoring solution for school laboratory network. Describes the laboratory network devices, their purpose and condition before applying configuration, it also contains a comparison of commercial supervision network systems and the choice of one that has been used. The essence of the thesis is focused onto SNMP protocol, its use in laboratory network monitoring. In the practical part of the thesis is created the system supervision configuration, which is applied into laboratory network and ensures the supervision and monitoring for whole laboratory network.
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