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Analysis of methods of measurement of fully-differential frequency filters
Kučera, Tomáš ; Kubánek, David (referee) ; Jeřábek, Jan (advisor)
This bachelor thesis focuses on measurements methods of differential frequency -selection filters with active elements in current mode. Firstly it describes differential frequency-selection filters in current mode and conversions from voltage to current mode. Next the thesis deals with measuring of particular voltage converters to differential current and back from differential current to voltage, which is an integral part for measurements of differential frequency-selection filters in current mode. For design of particular converters there was used program OrCAD there and subsequent simulation was executed in program PSpice.
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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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Laboratory device involving the high selectivity filters
Tuhý, Luboš ; Kovář, Jan (referee) ; Petržela, Jiří (advisor)
This project deals with the frequency filters of high selectivity. The area frequency filtering is fairly comprehensive and theoretically demanding discipline. The aim of this work isn’t to describe in detail and to include knowledge of the frequency filters, but only to clarify the aforementioned issues. In particular, we focus practically on filters working on other physical principles, especially on the crystal structure of partition filters and ceramic filters. The circuit simulation programs through classes Spice will be one of the parts of the theoretical analysis. There will be presented various options for implementing these filters, and the test products used in the design. The laboratory exercises dealing with frequency filtering and measuring engineered product will be made and based on the theoretical findings of this work. The laboratory exercises will include the developing of the model protocol.
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New solutions of converters for measurement of current-mode filters
Štork, Petr ; Kubánek, David (referee) ; Jeřábek, Jan (advisor)
This bachelor’s thesis describes some new solutions of differential converters that convert voltage to current and vice versa. Such converters are necessary for measurement of frequency filters in a current mode due to absence of instruments able to mesure signals with current as signal carrier. The goal is to design such converters that should influence gauged frequency properties in a current mode as little as possible. Converters will consist of operative amplifiers with current feedback. Converters designed this way are tested using simulations from PSpice programme, where particularly wideness of band of individual solutions is tested. Simulated solutions that are the most suitable ones are practicably re-enacted and gauged. These resuls of measurement and simulations are compared.
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A System for Monitoring Status of Network Links via SNMP
Zubčák, Peter ; Trchalík, Roman (referee) ; Rychlý, Marek (advisor)
The goal of the bachelor thesis is an implementation of the system for monitoring status of network links. System collects information from network nodes, from which calculates metrics and statistics, which are available for users in MIB. The communications with network nodes is proceeded by SNMP protocol. The system is implemented in C++ language as a multiplatform service.
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Implementation of Asterisk VoIP PBX
Schön, Martin ; Münster, Petr (referee) ; Szőcs, Juraj (advisor)
The thesis is divided into two parts, theoretical and practical. In theory, it analyzed the signaling protocols, the RTP protocol for data transmission, VoIP Asterisk PBX and security options. The practical part describes the installation of the Asterisk PBX, conducted demonstration call forwarding. PBX was associated with an LDAP directory server to manage users and ejabberd for text messaging protocol XMPP. It was configured translation SIP-Skype using the SiSky Gateway and with dialplan SIP-H.323 translation. The study was to develop Dialplan with IVR. It was measured bandwidth of the audio/video codecs in an encrypted/unencrypted connections.
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Optimization of WiFi Distributed Nets
Žlůva, Ivan ; Krejzlíková, Libuše (referee) ; Matoušek, Radomil (advisor)
This thesis describes theoretic proposal and two practical realization of multi - point wireless network, first for communications between two endpoints and second for wireless signal coverage of a structured space. The wireless network is realized by the equipment working in unlicenced 2,4GHz and 5GHz ISM band. The wireless device are configured in three different wireless mods: WDS, WDS bridge and AP. This paper contains short information about IEEE 802.11a/b/g/n standard and associated proprietary wireless specifications. Practical workshop describes several variants connections and present the result of throughtput measurements, depending on wireless network topology.
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Optimization of WiFi Distributed Nets
Žlůva, Ivan ; Krejzlíková, Libuše (referee) ; Matoušek, Radomil (advisor)
This thesis describes theoretic proposal and two practical realization of multi - point wireless network, first for communications between two endpoints and second for wireless signal coverage of a structured space. The wireless network is realized by the equipment working in unlicenced 2,4GHz and 5GHz ISM band. The wireless device are configured in three different wireless mods: WDS, WDS bridge and AP. This paper contains short information about IEEE 802.11a/b/g/n standard and associated proprietary wireless specifications. Practical workshop describes several variants connections and present the result of throughtput measurements, depending on wireless network topology.
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The effect of optical fiber attenuation on the capacity of optical traces
Žák, Ondřej ; Škorpil, Vladislav (referee) ; Reichert, Pavel (advisor)
The essence of this thesis is the creation of complex insight on optic fibre attenuation. There is successive steps explained mechanism of optical attenuation and characterized its spectral dependence. We are describing primary elements of optical attenuation, its sorts and their own spectral dependence. Bachelor´s thesis is explaining requirements of transmission system to spectral characteristic optic fibre and influence of optic fibre attenuation on capacity of optical trace. Output of bachelor´s thesis is program solution of designed mathematical model for calcula-tion spectral dependence of optical attenuation. Program is realized in MATLAB and there is furthermore added version in Microsoft Office 1997-2003. Created program is able to ap-proximate points data obtained from measurement of optic fibre by using Lagrange interpola-tion polynomial and Rayleigh scatter interlay.
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Quality of service support in unix-like operating system for communication in WiFi networks
Mizera, Josef ; Komosný, Dan (referee) ; Novotný, Vít (advisor)
Diploma thesis is focused on the supporting of Quality of Services in wireless networks, especially in the Linux operation systems. The topic is connected not only with OS, but also with the wireless standard, which supports QoS in wireless networks called IEEE 802.11e. QoS is needed especially for time-consuming data transfers in real time. The theoretical part deals with the theoretical analysis of the issue of the QoS support. There are described parameters, which occurred in quality of services support. This section also deals with the division of services that are used to transmit data across computer networks. It also describes the QoS support in wireless networks according 802.11e, its implementation and methods of accessing a medium with a without possibility of traffic. This part is followed by a description of QoS support in UNIX operating systems. The chapter describes how is the QoS support designed in these operating systems. There are also characterized concrete tools which are used for control the data flow in the operating systems using Linux. At the end the theoretical part deals with different types of queues and methods used in linux OS. In the practical part of the thesis, there are various designed topologies and scenarios to verify the functionality of QoS support in wireless networks using a Unix system. These chapters show the results of different tests at selected transmission data streams that are sensitive to transmission time. There is also verified cooperation of QoS support between devices operating on the network and data link layers. The output of this work is to design a laboratory exercise for the subject Network Architecture. This exercise is focused on familiarization with the QoS support functionality in wireless networks and in Unix-like operating systems. This chapter also describes the devices and programs that are needed to measure this task. The last part of the chapter describes the procedure for the preparation of the measuring station. For this laboratory task, there is an inserted manual in the annex.
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