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Generalized design of frequency filters with operational amplifiers
Dokoupil, Drahomír ; Minarčík, Martin (referee) ; Vrba, Kamil (advisor)
This thesis is about general design of frequency-selection filter with help of autonomous circuits. Operational amplifier has been chosen as active device/element. In the begining of this project is described role of frequency-selection filters in electronics circuits, their basic types and their transmission function. Another part of this thesis dissertate about construction of autonomous circuits, selection of suitable admittance network and it's simplification. Selected autonomous circuits are initial elements to find out known connections of frequency-selection filters. Last part of this thesis describing work with SNAP software, ways to find new connection of filter and describe how autonomous circuit works in voltage or current mode.
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Digitally controlled filter
Rez, Jan ; Szabó, Zoltán (referee) ; Friedl, Martin (advisor)
This bachelor's thesis deals with design of a functional prototype universal digitally controlled analog frequency filter 2th order. Part of the design is the selection of appropriate filter topology diagram and selection of an integrated circuit. Universal filter will contain lowpass, highpass, bandpass and notch filter. The filter is tuned in cutoff frequency from 100 Hz to 15 kHz. The bachelor's thesis focuses on the circuit analysis of selected concrete structure of universal filter and possibilities of digital control filters. The practical part of this thesis includes PCB design, control software for filter and graphical representation of measured results.
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Bluetooth Vibrating Ringer
Dočekal, David ; Dušek, Martin (referee) ; Povalač, Aleš (advisor)
This thesis is focused on the implementation of Bluetooth communication between a mobile phone and an external device. The first chapter focuses on Bluetooth technology in general. It describes the interface, device classes according to RF power, Bluetooth versions, security and pairing options. The second chapter of the Bachelor’s thesis deals with the Bluetooth module called HC-05. It describes the basic features and practical, module usage. It also shows the concept of the Bluetooth unit and describes the adjusting of certain parameters of the HC-05 module using the AT commands. The third chapter summarizes the deign and implementation of the device. Software and firmware development is overviewed in the fourth chapter. The testing and measurement results of the complete device are presented in the last part of this thesis.
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Network service testing with WAN network emulator and load simulators
Kocáb, Marek ; Krajsa, Ondřej (referee) ; Novotný, Vít (advisor)
The main task of this thesis was to explore the requirements of different telecommunications services on the network parameter, that are packet delay, packet loss, throughput, jitter. Make to test network service with WAN network emulator and load simulators. Next focus was to explore TCP congestion avoidance algorithms and focus on their throughput. The purpose of the first chapter is to introduce Quality of Service (QoS) for VoIP, video conversation, streaming audio, streaming video and data. The second chapter are to explore various types of delay, that are created from the sender through network device, transmission media to the recipient. The third chapter is to introduce NetDisturb application. It is application, that can emulate real properties of the data network and incoming traffic affect example packet delay, packet loss, bandwidth limit and so on. The key objectives of the fourth and fifth part is TCP protocol and TCP congestion avoidance algorithms. Hier are to introduce TCP protocol basic properties, congestion avoidance mechanisms and analysis of TCP congestion avoidance algorithms. In the practical part are created two laboratory exercises. First laboratory exercise is designed on the implementation QoS for various types of traffic. Second laboratory exercise is focused on the analysis TCP congestion avoidance algorithms and their throughput.
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Influence of optical connectors and of other effects on optical link attenuation
Winkler, Aleš ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
In this time the metalic wires meet not the requirements of high capacitance and rate wire and so the new, modern fiber wires are more and more being used. This bachelor`s thesis deals with three basic kinds of connections of fiber wires, optical connector, mechanical coupling a optical weld, and their effect on optical link attenuation realized by fiber optics. The optical link is possible realized number of kinds fiber optics. In this thesis are most often used multimod and a little multimod fiber optics. By mechanical coupling are explored their effects of attenuation on optical link a their detrition after disconnection and next connection back to the optical line. For optical weld is explored quality assignet optic welder. For optical connectors is explored their quality of cleanness through apparatus OTDR( Optical Time Domain Reflectometer) and geometrical properties through apparatus FIBO 250.
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Automatic configuration of workstations in Cisco academy laboratory
Homolka, Jiří ; Jelínek, Mojmír (referee) ; Komosný, Dan (advisor)
My thesis is focused on the subject of working with distant stations connected with the laboratory control of Cisco academy. Station operations, i.e. laboratory control, have been carried in the environment of the Linux operating systems. The first part of the thesis includes a description of the laboratory, its network architecture and software equipment. Also, the VMware tool is described here. VMware tool is intended for virtualization of computer stations, where the virtual station is created. In this virtual station another operating system may be run. The problems of the command interpreter, its function and possibilities are described here too. Main attention is devoted to the Bash command interpreter and to the creation of the scripts. There are descriptions of the basic tools intended for the network communication with the distant stations. Among the most important parts belong the protected communication, the production of the autentization keys as well as the tool for data recording on more stations at the same time. The description of the access rights to the files and directories is included too. The target of this thesis was to create the scripts in the Bash programming language. The scripts are focused on working with the laboratory stations. They are the sublayers of the common project for this laboratory control. They were developed for the cooperation with the the web interface and MySQL database, created by Bc. Zdeněk Hrabal. The Scripts are intended for the finding information about the stations and virtual systems, and also for the recording images and configuration files of the virtual systems at the distant stations. Recording files and directories is enabled too. The other scripts deal with the erasing and changing of the rights of the particular files and directories. Setting commads with the super-user competence is used at this place. The scripts for the switching on and off the laboratory workstations were created too. To solve the problem described above I chose to develope more scripts. Each of them subserves the particular part of the task. The form of the input and output data of the scripts was select with the reference to the cooperation with the web interface and database. The data are implemented by the form of the input and output files. The output information and the process of the carried operations are displayed through the web interface. The scripts together with the web interface are placed and run from the school server adela.utko.feec.vutbr.cz. In the thesis the settings of the access privileges for the current directories and the files of virtual systems and scripts are presented too.
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Converged solution of speech services
Mácha, Tomáš ; Kovář, Petr (referee) ; Novotný, Vít (advisor)
Development in VoIP technology is connected with the rapid growth of quality and data rate of the Internet connection. The application of the VoIP technology has become one of the key areas in telecommunication and networking. The main task of this thesis was to explore the questions of IP telephony and voice transmission over data networks according to H.323, SIP and Cisco architectures. Next focus was on designing and implementing experimental workplaces of mentioned architectures and their converged solutions. The purpose of the first chapter is to introduce the theory background of architectures required for implementation of real-time services in data networks and their comparison. The key objectives of the second and third part are to design and implement experimental workplaces containing signaling and proxy servers and hardware or software IP phones of several architectures. Illustration examples of different network topologies are included to demonstrate designed and realized VoIP solutions. Several tests of established communication are done using a packet analyzer. These tests examine duplex data transmission over IP. This article also contains two laboratory exercises designed according to gained practical experiences. The laboratory exercises provide an overview of theory and clearly indicate the possibilities of IP telephony.
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USB Host with PIC Microcontrollers
Kučera, Pavel ; Janoušek, Vladimír (referee) ; Hanáček, Petr (advisor)
The aim of master thesis is implementation of USB host in a microcontroller PIC. The thesis contains description of ways of peripherals to computer connections with detailed description of USB bus. There are also discussed several approaches in implementations USB host for embedded systems. A concept of layered USB host system is designed on the basis of analysis of the state of the art. Finally, the designed system is implemented in microcontroller. Resulting firmware of development kit is tested on real USB device.
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