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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.
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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.
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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.
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Software based optical cable documentation
Martínek, Michal ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The focus of this work is a description of search-optic cables and cables stored in the Earth's surface suitable method and the possibility of registration of the optical paths and components in the ArcGIS geographic information system. The work set out in detail the different types of optical fibers and principles listed in the wiring examples most commonly used cables. There are additional elements used in the construction of optical networks, whether the individual connectors, hubs, etc., as well as protection features most often used for distribution of optical cables. There are also examples given options stowages routes and laying cables, and most currently with the possibility to discover a practical listing and description of these search engines non-metallic elements. The work also focuses on how these elements efficiently record to go to them quickly and easily access and simplify their close location in real space, to ensure unwanted destructive interruption, or any repair, expansion, etc.
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Optical cabling - a comparison
Zelinková, Vlasta ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The thesis is focused on an analysis of mounting and cable laying fiber optic lines. The first chapter includes an analysis is made comparing parameters fiber and copper cabling, mainly in terms of access networks. This part specifies the various transmission media and access networks that are operated on them. Attention is focused on the transmission rate and its possible impact, provided the capacity and other important values. This section also demands site maintenance, service, or any failure on the routes of these networks. With this goal in the second chapter was created several designs networks that provide insight into possible solutions to the situation for emerging networks, and for upgrading existing networks, using both management and elements of optical and copper, or combinations thereof. Provide information from expert sources and verified directs the work of the future and to clarify further the eventual development of individual technologies. Most other space and offers the potential of optical technology, nature, and therefore the third chapter is fully devoted to only the transmission medium. At the beginning of this section is a theoretical analysis of possible ways of cable laying fiber optic cabling with a comparison of advantages and disadvantages. The most stable is an underground installation, which is costly in standard cases. As a result of these factors proved to be a possible solution using the underground installation of water pipeline shutdown. Therefore, the optical path designed, organized and implemented laying of fiber optic cable. By completing the inspection measurement and evaluation of the cost compared with other ways of installing fiber optic cable.
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Bragg gratings in optical fibers
Urban, František ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
Thesis focuses on the principles and properties of the tilted Bragg fiber gratings. Two models of the principal cladding mode behaviour are proposed and ther respective results compared with experimental data. The experimental setup for the preparation of the tilted gratings is described. The thesis shows the evaluation of the gratings parameters for the set of prepared gratings. Application of the tilted gratings in the sensors is discussed
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Optical Wavelength Division Multiplex
Kavický, Martin ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
This bachelor's thesis is orientated to problems about optical networks and possibilities of transmision more than one optical mode trough single fibre. Components, which create optical path, are described there. I was concerned with kinds of fiber couplers, optical multipexors and demultiplexers, proper souces and receivers of optical radiation, possible optical amplifiers and in not least turn single types of wavelenght division multiplexing. In practical part I propose possible ways of verification of activity of wavelenght division multiplexing and optical path components, as is EDFA amplifier, or circulator. As insertion of thesis, I created concept of active task, in which will students meat with meassuring optical power after way through EDFA amplifier, which they will tune.
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Effects of mechanical doings on optical data transport
Tihlařík, Tomáš ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
This master´s thesis deals with of human factor impact on optical fibers manipulation. It describes types and methods used for splicing and placing optical fibers and optical cables. These methods are specified in the chapters; their application in different environments and conditions is accentuated. This paper presents splicing optical fibers. It emphasizes problems which can occur if proper procedures aren´t kept or if improper device is used. In the thesis there is the chapter dealing with problems which can arise during splicing optical fibers - these negative influences are evaluated with educational equipments EF-970-01 PLASTIC by the company MIKROKOM, s.r.o. Another aim of the work is to describe mechanical optical fiber splice 3MTM FibrlokTM. This kind of device was lent for testing optical fibers multiple splicing. It was tested under extreme conditions. Statistically processed values of insertion loss and splice reflectance, measured by OTDR are the results of the test. Comparing measured values, technical report ones, regarding for usage in practice, there is a possibility of 75 multiple reusing of the mechanical optical fiber splice. The prediction of magnitude insertion loss, calculated for thousands splice cycles follows. The next part of the work deals with fusion splices and contains comparison of splices made with two cleavers: CORNING LWL-TRENNGERAT S46999-M9-D12 and the later model - Fitel S325A cleaver. The result is that older S46999-M9-D12 model gained lower attenuation. The results of both previous measurements are influenced by human factor. It appears at mechanical optical fiber splices as growing fluctuate of insertion losses and as the unequal attenuation fusion splices at tested cleavers.
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Coverage of signal - remote regionn
Grenar, David ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
Because the Czech Republic has been specific geographically rugged terrain. We could find a many places without a voice and data coverage. This place with worst signal coverage have sometime only the GSM technology, but this technology does not have high quality for calling inside building. The operators which are owner of GSM networks they don't care about how to make better coverage. The investment is more expensive than the profit of service. In 2012 was prepared auction of frequency for new LTE technology. In one of point was written that operators must start with building the networks at place with worst signal coverage, but in 2013 this point is missing. In thesis we will basically from our theoretical technological experience trying found out a solution of coverage in remote region. Our solution trying found out a best way between economic a technological transmission demand, between metallic, optical and wireless transmission medium. Next part is interest about compare properties, technical parameter and economics of building a type of network. Final step is building a real network distribution in chosen region.
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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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