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Laboratory device focused on the switched capacitor circuits
Urban, Lukáš ; Šotner, Roman (referee) ; Petržela, Jiří (advisor)
This Master`s thesis is focused on through acquaintance of principles of the function circuits with switched capaticors and posibility of their application mainly in frequency filters or signal generators. The origin of the switched capacitor circuits is mentioned at the beginning of the work. There are references to the first scientific work and scientists who have dealt with this issue. Maxwell`s idea: lossy element (resistor) replace with lossless element (switched capacitor) in electric circuit, is further described. In the next chapter of this work are listed types of switching capacitors and their use in simple RC filters and in structures of inverted or noninverted integrators and their application in more complex higher order filters. The advantages and disadvantages of SC circuits versus circuit composed of discrete components are shown. It is also listed a simple low-pass switched RC filter implemented with analogue multiplexer 4053. Using the LTC1043 integrated circuit, which structure and properties are described and analyzed in detail in the work, the 1st order aktive or pasive low and high pass filters were designed and subsequently simulated in the computer simulator OrCAD PSpice v.10. Another chapter deals with the integrated circuits higher order filters, structure and properties of the integrated filter LTC1060 are further analyzed here. Except this IC there are mentioned integrated filters commercially less available from the corporations Linear Technology and Maxim. The main objective of thesis was to propose and establish laboratory device and laboratory measurment focused on the switched capacitor circuits. The laboratory device has been designed with integrated circuits LTC1043 and LTC1060, which is demonstrated by using passive and active integrator, 2nd order band-pass and 4th order band-pass with Chebyshevovou approximation.
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Measuring of data communication parameters in computer networks
Šeda, Pavel ; Hošek, Jiří (referee) ; Skořepa, Michal (advisor)
Master‘s thesis is focused on basic characteristics of data transmissions in computer networks. In forepart I digestedly described basic characteristics computer networks, metods of their measurement and valuation. Computer networks type LAN as well as wireless computer networks Wifi, are mentioned. In second part I realized my own proposition of basic characteristics measurement. This proposition is used for SW applications development. Main goal of these applications is measurement of packet delay, packet jitter, paket loss and available bandwidth. I described details of SW applications and realized measurement of real computer networks in the end.
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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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Fiber optical transmission system
Horský, Tomáš ; Münster, Petr (referee) ; Dejdar, Petr (advisor)
Bachelor thesis deals with the program processing for the simulation of dispersion on the optical transmission. Parameters of optical fiber, such as attenuation, diffusion, dispersion, and bandwidth are described in the theoretical part. The main focus is on dispersion while being the key parameter of this work. In the practical part, the measurement characteristics of the eye diagram and its analysis are discussed. Simulator of dispersion can serve both for simulation as well as a measuring device for real transmission routes.
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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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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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Implementation of HDLC protocol in network simulators
Polášek, Jaromír ; Mašek, Pavel (referee) ; Pokorný, Jiří (advisor)
This diploma thesis deals with the possibility of using HDLC (High-Level Data Link Control) protocol for communication and addressing of smart metering devices with a data concentrator. The HDLC protocol is used in two DLMS/COSEM (Device Language Message Specification/Companion Specification for Energy Metering) communication profiles. To simulate these communication profiles, the most appropriate simulation program is selected. Using this simulator, the first communication profile is implemented and the second one is designed. Communication profile based on TCP/IP (Transmission Control Protocol/Internet Protocol) has been fully implemented. To implement the three-layer HDLC communication profile, all options have been thoroughly explored. Using these findings, a process was designed to guide the full implementation. For the first communication profile the qualitative parameters are measured, which are then plotted and evaluated.
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Design and realisation of microwave directional coupler
Nejedlý, Miroslav ; Motl, Milan (referee) ; Dvořák, Radek (advisor)
The diploma thesis deals with microwave directional coupler. The paper presents some of the microwave directional coupler and an analysis of bifurcations. The paper also discussed the various techniques of bifurcations and the bandwidth to which they are making. Proposal is implemented in two selected directional couplers and determining their size. They also performed using the selected simulation program selected two bifurcations. Furthermore, these couplers are made on the perimeter of the analyzer is verified by their actions and are verified by the actual parameters of the coupler.
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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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Classification of transmission channels based on speech signal analysis
Báňa, Josef ; Sysel, Petr (referee) ; Atassi, Hicham (advisor)
The thesis examines the impact of VoIP transmission channel characteristics on speech parameters. It seeks ways of emulating properties of a selected VoIP transmission channel and creating a network emulation environment. Several scripts have been created in the Matlab development environment and used to modify and divide a continuous recording into parts identical to the original speeches, before passing through the transmission channel. Subsequently a database of speech recordings is created, as affected by selected characteristics - jitter, bandwidth, loss. Within these databases, symptoms are sought as the most evident characteristics of the transmission channel. Using correlation, symptoms are selected that are best suited for automated determination of the properties of transmission channel characteristics such as jitter, loss and bandwidth.
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