National Repository of Grey Literature 201 records found  1 - 10nextend  jump to record: Search took 0.02 seconds. 
Optical information transmission - transmission security
Kondicz, Dávid ; Čučka, Milan (referee) ; Filka, Miloslav (advisor)
The submitted work deals with issues of optical transmissions and its security. We will become familiar with a variety of transferability of information, based on which we can assess the advantages and disadvantages of each technology as compared to optical information transmission. Based on acquired information we will try to implement interception of optical communication of cable TV provider.
OTDM to WDM conversion
Kupčiha, Lukáš ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The aim of this thesis was introducing the options of conversion between OTDM and WDM technologies. Since this issue is rather extensive, first of all the principle of optical transmission system is described. One chapter presents the effects influencing the optical transmissions. Material absorption, linear and nonlinear scattering and bending losses are mentioned in terms of fiber losses, followed by description of waveguide, chromatic and polarization-mode dispersion of optical fibers. Last part of the chapter presents nonlinear effects, including self-phase modulation, cross-phase modulation and four-wave mixing. The practical part of the thesis deals with multichannel systems. The principles of frequency, space a hybrid multiplexing are explained. Multichannel systems with optical time domain multiplexing and waveguide multiplexing are described in detail and compared. The elements of the transmission chain of multiplex, such as different types of lasers, detectors, modulators, optical amplifiers, splitters, couplers, MUX and DEMUX are discussed. The next part of the thesis was aimed at suggesting the model of mutual conversion between OTDM and WDM systems. First of all, the previously performed experiments concerning the conversion between OTDM and WTM were evaluated. Then the model of OTDM/WDM/OTDM conversion was designed, with explanation of its parts and their function. The general recommendations for practical implementation were are also included. Due to the limited amount of time reserved for access to the simulation program Optsim, the simulations were performed only for certain parts of the proposed conversion model. At the end of the thesis, the proposed model is evaluated.
Effects of assembling on quality of cable systems
Konvalinka, Vladimír ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
This master´s thesis deals with questions of measuring of cabling systems. There is described the evolution of structured cabling including the rules of their installation, approval and their final measurement. The first part of this work is dedicated to the conception of structured cabling and its history which originated at the beginning of 80s when the first personal computers began to appear at the market. The necessity of mutual communication of their users caused forceful development of networks and technologies. As a result lots of single-purpose, incompatible and mutual independent cabled distributions were developed. This method of cabling was uneconomical, very demanding on service and impractical for network expansion. That’s why the universal cabled system was developed whose baseline became a twisted pair. Characteristics of structured cablings are designed in order it could be possible to transmit whole rang of applications through them. Metallic cables and nowadays also optical cables are used for their installation. The cabling system consists of lots of other items among them we can rank items active and stable. It’s necessary to scale lots of criteria which involve the quality of data transmission in this network. The measurement is done by the devices which comply with basic requirements determined by the standards according to technology. There are described the rules and proper processes of installing cabling systems, which should be followed while installations. At the end of my thesis there are mentioned the results of the measurements on simulation segments of cabling system which serve as completion certificates between an installation company and a consumer.
Software defined networks
Flimel, Peter ; Smékal, Zdeněk (referee) ; Filka, Miloslav (advisor)
This diploma work describes the software-defined network focusing on optical networks. Subsequently designed their own software network that is implemented in the environment OMNeT ++. This work deals with SDN (software-defined network), and impact on current communications environment in the world of telecom-munications services.
Searching of metallic cables using geolocation systems and locator
Flídr, René ; Čučka, Milan (referee) ; Filka, Miloslav (advisor)
Subject of this work is a laboratory excersise, in which student will be going through a training polygon in an FEKT VUT area. Outcome of this work is going to be a mobile application, serving as a navigation and controll tool for students. They will be searching for control points of interests with copper lines under the ground. Then they will get information from theese lines with the help of copper lines searcher. Students should learn methods to search and localize copper lines as well as extracting data from them with the help of geolocalization andcopper lines searcher.
The transmission speed enhancement techniques in TKR
Šťovíček, Petr ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The purpose of this work is to assess and propose possible methods for increasing the transmission speed of the cable television distribution, concretely the UPC network in Brno. The first part of work collectively processes general knowledge and gives the reader into the issue. After that follows an analysis of TV cable networks UPC in Brno, especially view of data transmission. After familiarization with the physical aspect of the network is described data communications itself, including standard DOCSIS, respectively EuroDOCSIS. Particular attention is paid to factors that have effect on data transmission and speed. Benefit is the calculation of dividing ratio in different parts of the network and compared with the real load. As far as possible in the given work results of measurements with regard to the quality of the network. The last part is about how to increase speeds. Perspective solution is mainly a technology which is based on standard EuroDOCSIS 3.0, which introduces the concatenation of individual channels. Result of made tests of first cable modem EuroDOCSIS 3.0 confirms the very high speeds and currently preparedness for other major step in so long development of TV cable network.
Dispersion measurements of optical transmissions.
Motúz, Rastislav ; Urban, František (referee) ; Filka, Miloslav (advisor)
This thesis firstly theoretically describes phenomena which appear in optical fiber transmission. The theoretical part of the thesis deals with linear and non-linear phenomena, and later on proceeds to dispersions with a more significant effect on the optical transmission quality. It puts polarization to the centre of the phenomenon called Polarization mode dispersion (PMD), which is the main object of our interest. It leads to a deep PMD description from the point of view of polarization states, limit values, compensation methods, and methods of measurement. The practical part of this thesis deals with a draft of PMD measurement via Fixed Analyzer method. For the purposes of this measurement, we used the optical spectral analyzer MS9740A. In order to compare measured values, the proposed idea then proceeds to the reference measurement by using a modular platform EXFO FTB--200 in combination with CD/PMD module EXFO FTB-5700. Results of measurements have been evaluated for the limit values defined by the standard. In the last chapter of this thesis, the reference measurements are compared to the Fixed Analyzer method. All the advantages and disadvantages of individual measurement methods are identified at the end of this chapter too.
Trends in Access Networks
Štěpán, Petr ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
This work deals with the modern trends in FTTX, but mainly focuses on FTTH, who represents the connecting of fiber to the homes of the participants. Sum up the basic problems of communication on the optical fibre, followed by comparison with other types of access networks. Another part is the analysis of the problems of construction and a description of the optical network topologies and technologies used in FTTH. In following chapter are characterized active and passive elements forming AON and PON networks. Next part deals with the study of the most common services that can be on the optical access network to operate. They are mainly associated with the TriplePlay services. An integral part of the project is the study of management and supervision optical networks. In the main part is created real model situation where is the requirement for the creation of optical access networks with broadband of TriplePlay, followed by selection of appropriate options and detailed project with a selection of active and passive elements with economic balance.
Measurement of polarized light properties on the dense wavelength division multiplexing in optical-fiber sensor systems
Bučko, Kristián ; Grenar, David (referee) ; Filka, Miloslav (advisor)
The polarization of light is one of the most remarkable phenomena in nature and has led to many discoveries in the optical-telecommunications sphere. The master's thesis describes the basic knowledge about polarized light, which includes the types of light polarization, the issue of Poincaré sphere, polarizing ellipse, etc. Emphasis is also placed on the measurement of optical power, where the analysis of various types of photodetectors and also polarimeters was performed. In the practical part of this work, the design of the workplace itself is described in the diagrams. Also, all devices in the workplace are analyzed and subsequently demonstrated measurement in several scenarios. The final chapter is a discussion with the measured results and graphical dependencies, comparison and analysis of results.
FTTx networks
Všetička, Václav ; Reichert, Pavel (referee) ; Filka, Miloslav (advisor)
Fiber optic telecommunations

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