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Testing of optical networks
Šimoník, Jan ; Horváth, Tomáš (referee) ; Filka, Miloslav (advisor)
The aim of this bachelor thesis is to describe testing of optical networks physical layer by norms and recommendations (CSN, ITU and RFC). The first chapter provides a description of the individual optical fibers, their division and a brief description of each type. In the next part of this thesis, the methods and procedures for testing the various parameters of optical networks are described, according to specific standards and recommendations. The issue of testing quality of services is also described, primarily focused on triple play services, which are operated at optical access networks. The following is a description of the issue of access and transport networks, a draft of methodology for testing the physical layer of these networks is given. In conclusion, there is a chapter describing the practical measurements made on a passive optical network. In the annexes of this thesis the limit parameters of optical fibers used for the measurements and draft of the content for measuring protocol are listed.
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Ultrasonic field of level sensors measurement
Hlavatý, Radek ; Fialka, Jiří (referee) ; Beneš, Petr (advisor)
The paper deals with the description of the ultrasonic field around the piezoelectric sensors. The theoretical part serves as an overview for the understanding the ultrasound problematics. More closely studied is the phenomenon of ultrasound wave attenuation. At the end of the theoretical part, three different methods of field measuring were selected and described. The practical part of this work is a more detailed description of the whole measuring system available in the Continental laboratory, that has been put into operation. The system uses a reflection method to measure the ultrasonic field. Automated way of data processing in the form of a script in Python and a macro in Excel was designed. Uncertainties were determined by the test measurements, so was the repeatability of the measured results, that correspond to the physical theory.
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Transmission parameters of optical access networks
Ježek, Jaroslav ; Kapoun, Vladimír (referee) ; Havelka, Dušan (advisor)
The essence of this thesis is the cognition of theoretical basis for measuring on optical fibres, elements and optical wireway as well. This work describes the methods of measuring and detection of parameters of these networks. The gained knowledge is followed by its application on two laboratory tasks. The first task is focused on usage of method of embedded loss for measuring of attenuation of fibre and followed by usage of the method OTDR for localization of defect. The second task is focused on measuring of attenuation on passive optical element using only the method of embedded losses. The laboratory tasks were described and respective conclusion and findings were drawed from each other.
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Computer design of a digital radio link
Havel, Ladislav ; Nováček, Zdeněk (referee) ; Láčík, Jaroslav (advisor)
The Terrestrial digital radio links are used for transmitting digital information between fixed stations on a line of sight of a radio path. Each digital radio link has many characteristics and parameters for transmission. We require technical parameters in the design of digital radio link such as data rates and capacities. In this design we should take into account most effects of the electromagnetic waves propagation, if we want to meet user technical requirements of the link and if that link may correctly transmit digital signals with minimum errors. Prediction methods for the design of terrestrial line of sight systems are still in progress. Some effects of electromagnetic waves propagation and methods of the digital radio link design depend on natural variability and climate. The goal of this diploma thesis is to investigate methods for the design of terrestrial line of sight links with taking into account of ITU recommendation. Make computer program which implement this investigate methods
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Automated area measurement of precipitation intensity via a network of microwave links
Bubniak, Milan ; Pospíšil, Ondřej (referee) ; Musil, Petr (advisor)
Point-to-point microwave links can be utilized as a large sensor network to measure rainfall. This work deals with the application of this procedure in practice. The first part of the thesis deals with atmospheric precipitation in general and standard methods of their measurement; and the propagation of the microwave signal and various causes of its attenuation, focusing on the attenuation caused by rain and the recommendation ITU-R P.838. This is followed by a state of the art summarization of the measurement of rainfall by microwave links. In the second part of the work, a manual procedure for calculating rainfall from microwave link data is performed, taking wet antenna attenuation into account. Then the creation of a support tool in the C# language is being described, which supply the data to the functions of the RAINLINK rainfall calculation library. Several rainfall calculations that are validated by physical rain gauges are performed. Furthermore, the own Telcorain application for rainfall calculation is created in the Python language, based on the pycomlink library. It has a graphical user interface created in PyQt. Several rainfall calculations validated by rain gauges are performed again, and the results are compared with the RAINLINK library.
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Principles of transmission of optical beam by optical fiber
Lásko, Jan ; Rampl, Ivan (referee) ; Šporik, Jan (advisor)
The work is focused on spreading beam optical fiber parameters which may affect the passage of the beam fiber dispersion, attenuation, numerical aperture and mods. In sub-sections there are examples which solve the problems and also practical examples of visualization of numerical aperture, the chromatic, and polarization dispersion. The basic features of the new technology of fiber called microstructure and problems connected with it are described on the paper.
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Extension of optical fiber transmission system
Horský, Tomáš ; Tomašov, Adrián (referee) ; Dejdar, Petr (advisor)
The diploma thesis describes the elaboration of a program for the simulation of an optical transmission path. The work introduces the basic parameters of optical transmission, such as attenuation, dispersion and bandwidth. Furthermore, the techniques of line code and error detection are described in the work, especially a cyclic redundancy sum. The key parameter of this thesis is dispersion of the optical signal. The work includes the characteristics of the eye diagram and its analysis. The resulting program can also be used to measure the real transmission route and its parameters.
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Microbending fiber optic sensors
Švestka, Jiří ; Štohl, Radek (referee) ; Šedivá, Soňa (advisor)
This thesis deals with the influence microbending the transmitted signal at the bare optical fiber. Microbending influence on the transmitted signal is investigated in this work by changing the weight, power and water level in the tank by using this test fixture. The results of the experiments are proposed to enter the laboratory tasks to measure the impact microbending the transmitted signal in the subject line fiber-optic sensors (MOES).
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X-ray beam hardening effect simulation
Milek, Jakub ; Kolář, Radim (referee) ; Drastich, Aleš (advisor)
At the beginning of this work the physics related background and it’s interaction with matter is described, followed by explanation of filters influence on X-ray spectrum. Linear attenuation coefficient is described and so are other related physical quantities. In the end the description of a simulator is presented.
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