National Repository of Grey Literature 14 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Design and simulation of passive optical network PON
Mikauš, Jiří ; Krajsa, Ondřej (referee) ; Reichert, Pavel (advisor)
The aim of master's thesis was to demonstrate chosen PON network in simulation software OPNET Modeler. The work deals with passive optical networks. In particular, solutions that are based on the transmission of Ethernet frames. EPON and 10GEPON standards are described in theoretical section. EPON Standard was introduced already in 2004. Newer 10GEOPN is back compatible, which is ideal as a suitable solution for modern network with a high data rates demands. The practical part describes process of developing network nodes for passive optical network. EPON model was developed in simulation tool, that demonstrates basic features of the standard IEEE 802.3ah. The simulation results are demonstrated in last section.
Connection simulation between master and end unit in passive optical networks
Moravcová, Klára ; Kočí, Lukáš (referee) ; Horváth, Tomáš (advisor)
The purpose of this bachelor’s thesis is to introduce and explain the standards of passive optical networks, their way of establishing connection between master unit and end unit in a network, as well as creating a working simulation in Matlab. The first chapter of this thesis covers the description of optical networks. In the chapter, individual layers of the GPON standard by ITU-T and the EPON standard by IEEE are described. The process of an ONU unit activation towards the OLT unit of these standards is covered in detail. The thesis describes the following standards: EPON, GPON, 10G-EPON, XGPON and NG-PON2. The practical part covers the simulations of the mentioned standards, which are displayed in the form of graphs. The results are interpreted through comparison of the graphs with various input parameters (number of connected ONU units and the length of the distribution network) with a final evaluation of these results.
Characterization of scanning transmission electron microscopy images of thin biological sections
Novotná, Veronika ; Nebesářová,, Jana (referee) ; Krzyžánek, Vladislav (advisor)
Diplomová práce popisuje fyzikální principy mikroskopů TEM, SEM a STEM spolu s jejich vhodností pro pozorování vzorků citlivých na elektrony, jako jsou zalévací média či biologické vzorky. Dále je popsána příprava vzorků pro STEM (TEM) a popis interakcí, ke kterým dochází mezi primárním elektronovým svazkem a vzorkem. Součástí práce je také pojednání o zpracování mikroskopických obrazů s podkapitolou o metodách kvantitativního porovnání obrazů ze STEM. Praktická část práce je zaměřena zejména na měření úbytku hmoty zalévacích médií (Epon, Spurr, LR White) způsobený primárním svazkem elektronů v nízkonapěťovém STEM. Ultratenké řezy několika tlouštěk byly zkoumány při různých nastaveních mikroskopu (urychlovací napětí, celková dávka, proud svazku, čištění povrchu vzorku a komory mikroskopu) a zobrazovacích módech (světlé a tmavé pole). Dále jsou zkoumány také biologické vzorky Krásnoočka štíhlého (Euglena gracilis) zalitého v pryskyřicích Epon a Spurr. Nasbírané snímky, vytvořené algoritmy a získané výsledky jsou diskutovány a zhodnoceny.
Simulation and measurement of triple play services in FTTx networks
Horváth, Tomáš ; Münster, Petr (referee) ; Šifta, Radim (advisor)
The aim of this thesis was to ascertain with the measurement methods of passive optical networks and the creation of a simulation model that corresponds to the measured network and comparison of results. The first chapter deals with Triple Play services, which are focused on different services (transmission of television signals, voice and data transmission). Each service consists of a subchapter and presents a detailed description of the parameters associated with the transmission. The second chapter of the theoretical part consists of an analysis of passive optical networks according to termination method of FTTx optical fiber. Partial part of this chapter consists of description of standard passive optical networks APON, BPON, GPON and EPON. The EPON standard is explained in detail. The theoretical part of the thesis is concluded with a description of active elements that will form the laboratory measured network. Testing of designed passive optical network is performed in the practical part of the thesis. The measurement is divided into two chapters. The first chapter consist of measuring of the „inanimate network“, as there are missing active elements in the nominated net. Network measurements were done by a direct measuring method and reflectometric method. The second chapter of the practical part consists of measuring the parameters of quality of service (QoS). This chapter is divided into subchapters, such as: the measurement using RFC 2544 standard, the measurement using ITU-T standard Y.156 (EtherSam) and bit error rate testing (BERT). The practical part ends with a designed simulation network model, which was proposed in OptSim 5.2. The aim of the simulation model was to maximally resemble a real network, due to result comparison.
FTTx networks
Hradílek, Pavel ; Reichert, Pavel (referee) ; Filka, Miloslav (advisor)
The aim of this thesis is to clarify the issue of optical access networks, and to acquaint the reader with problems of their design and implementation. The introductory chapter describes the technologies and topologies, which are the most experienced in dealing with optical access network. There are a comparison of their basic parameters and limiting factors. Another part of the work is dedicated to progressive methods of construction such as microtubes and solution using the hanging cables, which due to the efficiency of construction, rapidity, economic and facilitate implementation. In conclusion the theoretical part there is issues of measurement. It describes a Optical Loss Test Set, OTDR method and method of measuring dispersion. Increasing demands on the capacity of the transmission paths, and their quality are caused of monitoring optical access networks, which can evaluate the failure on a route, target problems and inform service. The practical part compares EPON and GPON. In program OptiSystem was created model which these technologies are evaluated in terms of performance parameters, noise, jitter and eye diagram quality. The common feature of technology is transmission TDM frames, where EPON uses Ethernet and GPON technologies ATM. The outcome of simulation don´t show which technology is better, but result shows the conditions of the proposal of these technologies. At the end of work there are created several models for solving the optical access network with pricing per user. The most developed technology is FTTB in urban areas, when transmission in last mile uses copper circuit. This solution causing a rapid return on investment. Other technologies such as point-to-point FTTH or PON are implemented as individual proposals. Each of these solutions has advantages and disadvantages, so each project is unique and the solution is dependent on the project site and the requirements of customers.
Design of new laboratory exercises with gigabit passive optical network
Chlápek, Jan ; Škorpil, Vladislav (referee) ; Horváth, Tomáš (advisor)
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.
Design of FTTx optical access network
Münster, Petr ; Tejkal, Vladimír (referee) ; Reichert, Pavel (advisor)
The aim of this work is an overview of the proposal for FTTx Optical Access Networks. In the introductory chapter written about the optical fiber and the transmission. Furthermore, as already discussed various options with regard to the implementation instead of the end of optical fiber - FTTN, FTTC, FTTP, FTTB, FTTH and standards, which are used to build fiber optic networks. The next chapter is an overview of the network elements that are in different layers reference model ISO / OSI used. The final theoretical chapter is devoted to progressive technologies for the construction of optical access networks, which has recently been used. Concepts are explained as HDPE pipe, microtubing or self-supporting cables. The practical part design model, passive optical networks in the area Slavičín, located in the Zlín region. FTTB architecture was chosen, where for each connection object is used in the existing copper lines. The proposed route will use a standard technology GEPON Wavelength division WDM, so to connect the individual buildings will be used only one thread. Realization of optical networking technology will be excavation. The optical cables and optical fiber bundles are protected by HDPE pipes stored in the bed of sand. For the optical signal split into multiple lines will be used by an optical splitter 1 / 16, located in an outdoor cabinet optic pathway. The distribution of signals for the settlement will take care Alloptic central station, which is optimized for the transmission of Triple Play services. On the basis of the proposal is to created a financial analysis that shows the return on the project. An important part of the network is also monitoring the network. The last part of this work therefore deals with the possibilities of monitoring networks in order to continuously monitor the network, in order to prevent any disturbances or quickly respond to network problems.
Design of new laboratory exercises with gigabit passive optical network
Chlápek, Jan ; Škorpil, Vladislav (referee) ; Horváth, Tomáš (advisor)
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.
Connection simulation between master and end unit in passive optical networks
Moravcová, Klára ; Kočí, Lukáš (referee) ; Horváth, Tomáš (advisor)
The purpose of this bachelor’s thesis is to introduce and explain the standards of passive optical networks, their way of establishing connection between master unit and end unit in a network, as well as creating a working simulation in Matlab. The first chapter of this thesis covers the description of optical networks. In the chapter, individual layers of the GPON standard by ITU-T and the EPON standard by IEEE are described. The process of an ONU unit activation towards the OLT unit of these standards is covered in detail. The thesis describes the following standards: EPON, GPON, 10G-EPON, XGPON and NG-PON2. The practical part covers the simulations of the mentioned standards, which are displayed in the form of graphs. The results are interpreted through comparison of the graphs with various input parameters (number of connected ONU units and the length of the distribution network) with a final evaluation of these results.
Characterization of scanning transmission electron microscopy images of thin biological sections
Novotná, Veronika ; Nebesářová,, Jana (referee) ; Krzyžánek, Vladislav (advisor)
Diplomová práce popisuje fyzikální principy mikroskopů TEM, SEM a STEM spolu s jejich vhodností pro pozorování vzorků citlivých na elektrony, jako jsou zalévací média či biologické vzorky. Dále je popsána příprava vzorků pro STEM (TEM) a popis interakcí, ke kterým dochází mezi primárním elektronovým svazkem a vzorkem. Součástí práce je také pojednání o zpracování mikroskopických obrazů s podkapitolou o metodách kvantitativního porovnání obrazů ze STEM. Praktická část práce je zaměřena zejména na měření úbytku hmoty zalévacích médií (Epon, Spurr, LR White) způsobený primárním svazkem elektronů v nízkonapěťovém STEM. Ultratenké řezy několika tlouštěk byly zkoumány při různých nastaveních mikroskopu (urychlovací napětí, celková dávka, proud svazku, čištění povrchu vzorku a komory mikroskopu) a zobrazovacích módech (světlé a tmavé pole). Dále jsou zkoumány také biologické vzorky Krásnoočka štíhlého (Euglena gracilis) zalitého v pryskyřicích Epon a Spurr. Nasbírané snímky, vytvořené algoritmy a získané výsledky jsou diskutovány a zhodnoceny.

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