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Wireless optical links in LAN and MAN networks
Šporik, Jan ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
The main aim of this thesis is the design of an optical wireless link that is transmitted in free space, in the atmosphere. The thesis describes the composition of heads of the atmospheric optical link. One part of this work focuses on the issue of the spread of optical beam in the atmosphere. The facts which have a major impact on the transmission of optical radiation in free space are pointed out here as well. In this work phenomena of absorption, refraction of light, turbulence and dispersion are discussed. Wavelengths spread in the atmosphere with different decline and therefore this thesis provides an analysis of the use of wavelengths between 750 and 1600 nm depending on the meteorological visibility. It describes the basis of the design of AOS through stationary model using power balance equation. It depicts the description of the statistical model, which makes possible to determine the availability on the basis of probability. Current possibilities of AOS are in general described in this work. The practical part of the work is focused on the design of simulation model of transmitter and receiver AOS in the program Pspice. The receiver and transmitter are designed to replace transiver in the media converter. The receiver plays a key role, and therefore big part of the thesis is given to it. Receiver model is composed of a photodiode and of an transimpedance amplifier. The receiver circuit has been tested. The model of transmitter shows the principle of modulating of current, which flows in laser diode. This work does not carried the model of atmosphere, which would serve as a link between the receiver and the transmitter. The circuit of the receiver is subjected to the noise analysis. Parameter NEP and SNR is designed. Link budget is calculated for models of the receivers and the transmitters. The maximum distance of heads is set based on the requirements for a BER error rate which combine this condition. The design of the practical implementation results from the models of transmitters and receivers. Printed circuit boards are designed in EAGLE. Within the frame of this thesis no curcuit diagram is carried out.
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QoS Implementation in Access Network
Adámek, David ; Molnár, Karol (referee) ; Filka, Miloslav (advisor)
This diploma thesis deals with computer networks which play a key role in present society. More and more demands are placed on these networks (especially on quality of services and throughput) because of fast-growing developement of services such as voice and video real-time transmissions. All the packets in typical Ethernet networks are equal. Therefore it is sometimes impossible for the application to maintain required throughput speed of a network. For this case it is useful to take some mechanisms into the consideration. These mechanisms (sometimes called QoS) are able to distinguish different types of transmissions and traffic, analyze them and then prioritize them according to some pre-defined set of rules. The most famous mechanisms are Integrated Services and Differentiated Services. The implementation of Differentiated Services is the goal of this thesis.
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FTTx access networks
Hladký, Miroslav ; Filka, Miloslav (advisor)
This graduation thesis addresses questions of deriving benefits from the FTTx optical access network. This project is divided into four main subject surveys. First part contains familiarization with individual architecture of FTTx network, topology of network and the use of components in these access networks. Second part shows how ideal optical access network is for distribution of modern multimedia services which pose great demand on the width of transmission band. It also shows success and trend growth of integration of the optical network into access segment in the Czech Republic and the rest of the world. The choice of right proposal and follow-on project of FTTx optical access network in assigned location is described in part three. It also compares investment costs needed for implementation of these proposals. Final part of this project shows financial budget and return of investments of a proposed access network. It also includes a contemplation of optical access network’s development.
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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.
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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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FTTB Network Design
Reichert, Pavel ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The purpose of this master’s thesis is to explain the issues of the FTTx network design. The main idea of this work is to describe to readers the methods of the designing the optical access networks. Especially we will speak about the building technologies and different topologies used in a practice. The different technologies of optical access networks’ building and various parameters, which are necessary to take into account in the designing of these networks, will be introduced. In the theoretical part, methods of measurement, which are like the needed part of each optical access networks’ building, will be described. Two purposes of the FTTB networks with all proprieties will be made and offered. One purpose will be solved by Point to Point topology and the second purpose will be solved by Point to Multipoint topology. Following the confrontation one of these purposes will be chosen and realized. By ITU recommendation, measurements will be performed on the built optical trace. The final protocols will be elaborated from these measurements. The built trace with all final reports will be prepared for assignment to the subscriber.
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Optical Amplifiers
Mlejnek, Zbyněk ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
Optical amplifiers has sparked a revolution in the telecommunications industry during th last ten years. Optical amplifiers are devices that amplifies an optical signal directly, without the need to first convert it to an electrical signal. Its ability to provide low-noise amplification over a range of wavelengths, fortuitously correspoding to the low-loss of silica fiber, has made optical networks economically attractive
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Application of ArcGIS Program in Telecommunication Networks
Štohanzl, Pavel ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
This thesis deals with the issues of locating and marking both metalic and optical transmission network. The choice of an appropriate program for creation and management of map document is discussed. In the following chapter some necessary adjustments to the ArcGIS ArcView program are made so that it is applicable to the field of telecommunication networks. The last chapter addresses the design of documentation options in optical transmission network. For metalic cables the possibilities of attaching transmitter to a cable and locating the induced magnetic field is covered. Among the methods for finding optical cables we list ways of locating through the use of markers, GPS location and added metalic conductors. Fundamentals of markers and their types are thoroughly analysed. In the chapter on GPS we examine how this system works and evaluate its accuracy. The next chapter enumerates requirements that a program should meet. We analyse properties of considered programs and evaluate them with respect to these requirements. For a chosen program the possibilities of enriching it with selected map document are discussed. For these map document, information about their applicability and source is presented. We also quote the cost for these maps wherever possible. The last chapter treats ways of documenting optical networks.
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Software solution of documentation of buried cables
Zavadil, Pavel ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The content of this work is focused on the production of software solution of documentation and on the work procedure leading to the production of software documentation for telecommunication network and mostly for its optical part. As the production of metallic and optical part is from the global point of view the same, only a change of attributes will take place because of the different characteristics of both media. The basis of every computer documentation is software, that is why we need to pay special attention to its choice and we should firstly make a list of requirements, which should the software fulfil. The essential requirement is the connection of database and graphical parts of the documentation. Once we have chosen the software with the requested requirements, we can approach the proposal itself. For the maximal accuracy of the input data we use only geodetically focused data. For the production of a database work is crucial the cooperation of all the users so that every future user has for him necessary data at his disposal. All the theoretical approaches are examined in the last part of this work on the project produced for a company SELF servis which requires the production of software documentation of its network. Documentation is based on the software ArcGIS, which is not aimed directly at the telecommunication purposes, but which enables the connection of graphical and database data and fulfils all the requirements made by SELF servis company. Among these requirements belong the possibility of usage of different types of bottom maps, the possibility of connection of database with the external SQL database and also restrictions to data access.
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Effect of optical connectors quality on transmission
Bernkopf, Miroslav ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
This diploma thesis deals with optic fiber connectors and their influence on transmissions realized via fiber optics. Optical fibers and lightguides play the key role in telecommunications because of constant demands of higher bandwidth and data rates. Original metalic wires do not meet market requirements and so the fiber optics are more and more being used. There are various types of fibers and there are also many ways of connections. This work deals with demountable way of connection – optical connectors, which have the biggest influence on a total attenuation and route length. Connector has to meet various requirements such as cleannes, quality, mechanical construction and ferrule polishing.
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