National Repository of Grey Literature 44 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Passive optical networks WDM-PON
Havliš, Ondřej ; Šifta, Radim (referee) ; Münster, Petr (advisor)
The work deals with optical access networks, passive optical networks, especially WDM-PON. Features a modern solution to connect users to the optical access network using optical FTTx connections. Describes the different types of FTTx connections, their parameters and construction technology. Practical work is a practical application of theory for the development of various design and simulation of WDM-PON networks. Each proposal includes the construction of technical solutions optical access networks, the technology used and the balance of the reduced pricing WDM-PON network. The penultimate part of the work consists of design models simulated WDM-PON networks by the simulation program OptSim. The conclusion deals with the evaluation of individual design and simulation of WDM-PON networks.
Fiber optic sensors
Janďourek, Leoš ; Šifta, Radim (referee) ; Čučka, Milan (advisor)
Term paper deals with optics, optical fibers and in particular with optical sensors, which are described in more detail. Furthermore, we introduce a new simulation program from VPI photonics. We will show the user interface and the possibiliti of sumulation in it.
Optical fibre sensors
Gallo, Martin ; Šifta, Radim (referee) ; Münster, Petr (advisor)
The aim of this thesis is to examine in detail the possibility of fiber as optical sensor. This work deals with optical fiber sensors, their distribution and use. Describes the most renowned types, their advantages and disadvantages. At the beginning of this thesis there is an introduction to optical fibers, description of well-known linear and nonlinear phenomena occurring in them, development of optical sensors. Sensors are cleraly divided by usage and common attributes. The paper focuses on distributed optical fiber sensors and includes two different designs of these sensors there are also basic principles in designing distributed sensors. At the end of the work, the sensor using Brillouin scattering measuring vibration is simulated in the simulation program. Viewed transmitted signal spectra are shown and conclusions of results are drawn.
Polarization sensitivity of the fibre optics grating sensors
Babieska, Lukáš ; Šifta, Radim (referee) ; Urban, František (advisor)
This diploma thesis deals with the effect of full-length fixation of optical fiber gratings on their polarization dependence. In addition, the effect of primary protection and parameters of optical fiber gratings on their intrinsic polarization dependence was also investigated. The theoretical part of the thesis briefly describes the historical development of optical fiber gratings, the types of optical fiber gratings used and also describes in detail the principles of polarization dependence of optical fiber gratings and the mechanisms of polarization dependence of optical fiber gratings. In the practical part of the thesis, suitable measurement methods for measuring the polarization dependence of optical fiber gratings are proposed. Furthermore, these methods are optimized and used for subsequent measurements of the effect of fixation on the polarization dependence of optical fiber gratings. Many different methods of fixation of the optical fiber gratings were then used to measure the effect of fixation, and the degree of polarization dependence of the optical fiber gratings was evaluated for each of the different fixation methods. The practical part of the thesis is concluded with a detailed summary of the results obtained.
Simulation and measurement of dispersions in optical access networks
Kováč, Filip ; Münster, Petr (referee) ; Šifta, Radim (advisor)
Thesis deals with detailed description of the chromatic dispersion–CD and polarization mode dispersion–PMD. In theoretical part is dismantled at the beginning of words and mathematical principles of dispersion, further distribution of dispersion in terms of single-mode and multi-mode optic fibers through compensation, either fibers (chromatic dispersion) or systems (polarization mode dispersion). Theoretical part also consult the standard ITU-T specifically in term of fibers G.652, G.653, G.655, G.656, G.657, are described and compared. The penultimate section deals with major subject and by measuring both of the above dispersions. Finally, the theoretical part is devoted to optical access networks, which describes the optical access network such as its division and at the end describes the different types networks as APON/BPON, GPON, EPON, 10GEPON and XG-PON. The practical part is divided into measurement dispersions (EXFO FTB-5700) and simulation dispersions (OptSim). Both steps use the same type and length of fiber (6 km G.653, 20, 60 km G.652). According before creating the measured and simulation diagrams are obtained fibres parameters, which are finally compared.
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.
POF - Polymer optical fibers
Janovský, Marek ; Šifta, Radim (referee) ; Filka, Miloslav (advisor)
This document informs readers with polymer optical fibres (POF). The first section summarizes basic properties and differences between polymer and glass optical fibres. The second section contains list of POF types, their differences in the structure and refractive indexes. Further is described preparation of fibre surface for connector pin and connector types, which are used for POF. Next section contains usage of POF in access networks, types of access networks and FTTx network types. The document continues design of FTTH, FTTB and LAN for home application. The practical part deals with basic measurements with POF, production of coupler and measuring response at test ranges. The final section summarizes the overall findings and results.
Analysis of optical access networks in the Czech Republic
Štefančík, Matej ; Šifta, Radim (referee) ; Münster, Petr (advisor)
The work provides an introduction to optical access networks. Describes the basic functional units, the architecture of these networks, defines the basic network elements. Discusses various construction technologies from classic to modern. The next chapter analyzes optical access networks in the Czech republic. Focused on actual status of these networks, based on statistical data. An important part is the future direction of development over the next few years. The new trends and ideas that appear in this field. At the end of the chapter was summarized anonymous survey conducted through a questionnaire sent to the owner of the optical access networks, the output of which were the parameters of the networks. All collected data served as a source for design creation of the standard variants of optical access networks along with the technical specifications and financial balances. For individual network designs were developed models in the simulation environment used for the analysis. The last chapter briefly compared strengths and weaknesses of created variants of the optical access networks.
Usage of polarization multiplexing in optical access networks
Jakoubek, Petr ; Čučka, Milan (referee) ; Šifta, Radim (advisor)
This thesis reviews polarization multiplexing and its similarities, advantages and disadvantages to other types of multiplexing methods. The basics of optical fibers and its effects on transmission are discussed in terms of commonly used multiplexes. Additionally, divisions of optical access networks and multiplexing methods which could be used simultaneously with polarization multiplexing along with active and passive elements used for high-speed transmission such as polarization multiplex are described. Practical measurements of temperature influence to polarization and signal crosstalk in the amount of 70 °C and -40 °C are also included. The practical and theoretical measurements on 1 Gb signal led in G.652.D fiber for different situations are examined. Measurements containing 1 Gb signal includes test on triple play services (voice, video, data). First practical measurement on 1 Gb transmission shows how white noise, representing analog television, transmitted in the first polarization beam affects the signal in the second polarization beam. Second practical measurements show how two data streams transmitted through a single fiber at the same wavelength, but different polarization beams, creates a full duplex connection between two network elements. Results confirm the possibility on the usage of polarization multiplexing in optical access networks at common temperatures.
Modern optical access networks
Třetina, Vítězslav ; Münster, Petr (referee) ; Šifta, Radim (advisor)
The bachelor’s thesis is about technology of passive optical networks. In the introduction, the paper focuses on introducing the basic functional elements of the networks and describes the different possibilities for implementing fiber optic lines as close as possible to the user. The main goal of the theoretical part of this work is the analysis of the various standards of passive optical networks. These specifications are described in the second and fourth chapter, where are discussed their different technical parameters. Particular attention is given to the technology of wavelength division multiplexing. The conclusion of the theoretical part is devoted to the description of the measuring instruments which are suitable for measuring C/DWDM systems. The practical part of this thesis is divided into two sections. The task of the first section is about creating two animations where the first of them shows the principle of passive optical networks based on wavelength division multiplexing (WDM - PON). The second animation is focused on the practical demonstration of a combination of wavelength and time division multiplexing (WDM/TDM - PON). The second section of the practical part consists of simulating multiple scenarios of passive optical networks in the OptSim 5.2. In these scenarios are searched for maximal possible parameters PON networks such as reachable attenuation, reachable distance or split ratio.

National Repository of Grey Literature : 44 records found   1 - 10nextend  jump to record:
See also: similar author names
6 Šifta, Radim
Interested in being notified about new results for this query?
Subscribe to the RSS feed.