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Cableless optical transmission
Němec, David ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
This diploma thesis first handles the general issues concerning free space optics in the atmosphere, which will then discuss the components and adjustments modification RONJA in laboratory. The aim is to simplify the control of laboratory FSO with programming compensation for HyperTerminal and provide external simulation influences on the FSO measurements in non-standard situations such as fog. It was created RONJA terminal with just cursor control to communicate with the serial port, ping, and FTP protocol. In the last part of this work were measured by an abnormal situation on the optical link RONJA.
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Methodology for the measurement of optical arterial network
Chleboun, Jan ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
There are methods to extend the transmission channel of optical transmission medium thanks to the development of telecommunications and informatics. Multiplex is a grouping of signals into a single transmission path and wave-division multiplexing is the best reason of use of the maximum fiber optic transmission capacity. The subject of this work is to determine whether a particular transmission path is suitable for such an extension of their capacity and how much. The answer is obtained by measuring the attenuation, the chromatic dispersion and the polarization mode dispersion, whose values are strictly limited and which determine next steps in the expansion of the transmission path, which is comprised by optical medium. Measurement methods determine the nature of the measured route and its current transmission capacities. Draft of the measurement methodology, which ensures the correct procedures during a possible transition to higher speeds is the output of this work. Thanks to the acquired characteristics of the BAPS (the Brno Academic Computer Network), the bit rate 40 Gb/s can be provided on this part of the network under the conditions of the introduction of certain countermeasures, particularly the exchange of a connectors on the measured optical lines. As for the back reflection lines in excess of the standard recommendation and pre-emptively on the lines with values with still agree with the return loss. Countermeasure for limiting of the chromatic and the polarization mode dispersion are do not need to stand in the way of a planned transition to a higher rate of the BAPS.
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Optical Convertors
Chleboun, Jan ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
Optical converters are used in various types of optical networks to provide end-users of data and voice services and also allow reception of television broadcasting, which is transmitted through optical media. The current trend is the construction of FTTH networks (Fiber To The Home), which, thanks to optical fibre, have reduced the speed or capacity, as in the case with metallic networks. The proposal is the need to consider positive and negative factors associated with building of concrete network with a specified number of users and location. Each network consists of passive and active components. Passive can be used for transmission of information, therefore they are mainly elements transmission medium. Active part includes elements for sending and receiving information transmitted by optical media. Transmitters vary their technical implementation, quality and reliability. This obviously affects the price of both active and passive parts. The cost of the operation of the network are also increased with demands of control. The advantage is the efficient management, which is guaranteed by return of the cost to build a FTTH network. Optical network with a system of remote management converters is a new trend of optical communications.
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Optical cableless transmission
Němec, Filip ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
This diploma thesis first handles the general issues concerning free space optics in the~atmosphere. The aim is to design and implementation of optical wireless equipment, which would serve in the laboratories of optical networks. Ronja was used as the basis for a~wireless link, which is already widespread in the world. Students will work with the device, which they may come into contact in the future. It consists several separate modules: transmitter, receiver and inteface. Each module have a separate chapter describing the~functional blocks and circuit realization. Ronja was adjusted for the needs of~laboratory tasks, where additional voltmeters measures received signal strength (RSSI) at~both ends of the link. Measuring device provides adjustment of power the transmitting LED via~computer, measures and sends RSSI values to a PC via~USB or RS232, turn off Ronja with computer. For targeting the pipes of Ronja was developed the mechanical design. In the last part of thesis the device was undergone a series of tests.
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Laser transmitter with fiber
Hašek, Jaroslav ; Němeček, Jiří (referee) ; Wilfert, Otakar (advisor)
This master´s thesis deals with communication which is provided by optical devices. Optical wireless links are enforced due to high bit rate, responsibility and noise immunity. Main part of this master´s project is devoted to optical fibre, its characteristic and its usage in laser transmitter.
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Polarization mode dispersion
Turský, Aleš ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
The work deals with dispersive effects of single mode fibers. We learn about the chromatic dispersion, the main attention is paid to the Polarization Mode Dispersion. We clarify the root cause origin of the Polarization Mode Dispersion describing parameters and its effect on transmitted data. Further on, the works dedicates to measure methods of the Polarization Mode Dispersion which is the interferometric method or the POTDR method. We explain the ways of the PMD removal at contemporary optic routes and options of PMD compensation by using compensators of various types. There is also mentioned the possibility of profiting from the soliton transmission. The last chapter deals with measuring of a real optic route. It includes measured data and its evaluation due to the ITU-T demands.
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