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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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Electric and Hybrid Vehicles Analysis
Slaběňák, Patrik ; Kuchyňková, Hana (referee) ; Hájek, Vítězslav (advisor)
Nowadays, oil resources start to decrease, therefore it is necessary to think about alternative sources of energy. The result of this semester project is a basic overview of the current development of electric and hybrid cars, with potential application in normal operation and the proximity of their main characteristics, such as mileage, price and service when traveling. The energy required to operate the electric stored in batteries are recharged using the power stations, which is also devoted part of the work. The thesis focuses on the design and calculation of power consumption for a defined route of four-wheel electric wheelchair. The conclusion of the thesis deals with the future development of hybrid and electric vehicles, and with the expected trends in the field of power electronics and motors and with the propagation of hybrid vehicles to the customers.
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Real-time protocol implementation
Procházka, Jan ; Skořepa, Michal (referee) ; Burget, Radim (advisor)
Thesis deals with multicast broadcasts, discusses the type of ASM and SSM. Also deals with the principle of RTP / RTCP protocol for large multicast groups, for example, broadcasting IPTV. It was created a model for simulating the behavior of the network load in a large number of receivers. The application was developed in Java and uses the recommendations of RFC3550. There are also analysed processes of communication, initialization, log out, the structure of the data packets and signaling packets. The system is designed that can simulate multicast network and obtain the estimated parameters of the operation, or can operate in real traffic, for example, as a third-party monitor. In both modes, the measurement was carried out model situations. The results of the measurements were then compared. Principle and system control was described in detail. Output measurements are graphically processed and included in the work.
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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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RF channel simulation in the MATLAB environment
Daďa, Petr ; Kratochvíl, Tomáš (referee) ; Štukavec, Radim (advisor)
Subject of this thesis is elemental description of DVB digital television and digitalization process of its terrestrial transmission according to DVB-T standard. The thesis characterizes in detail RF transmission channels used for wireless distribute of television. These channels ale mathematically described and their effect to OFDM signal is simulated in the MATLAB environment. It was created application with graphical user interface by this environment. Using simple setting of DVB-T and transmission channel parameters in the application user can simulate selective fading. Results of simulations with various settings are compared and analysed.
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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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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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Tuner for UHF Receiver with Low Power Consuption
Kaštánek, Martin ; Vágner, Petr (referee) ; Urbanec, Tomáš (advisor)
The purpose of this work was to make a proposal for input parts of receiver for band 430 to 440 MHz. A model of chosen semiconductor triode BFP540 was created in simulation software. Possibilities how to decrease consumption of this semiconductor triode, keeping the profit, were investigated through the simulation.In compromise consumption, keeping the profit of the amplifier - an optimal operating point for this semiconductor triode UCE = 1,2 V and IC = 2 mA was found. It was tested through the testing wiring with noise microstrips conformity. Ascertained knowledge was used for construction of tuner for UHF receiver. An operating point of input amplifier of UHF receiver was owing to power supply amplifier forced for bigger effectiveness to UCE = 2,65 V and IC = 2,0 mA. Suppression of mirror frequency is provided with Helix filter of the third order, because of intermediate frequency 10,7 MHz. Mixing on intermediate frequency is made again by semiconductor triode BFP540. Selectivity of receiver is provided with intermediate frequency crystal filter 10,7 MHz with bandwidth 15 kHz. Designed input part enables reception of SSB, FM and digital types of modulation.Bandwidth intermediate frequency exit is adapted to this request To receive particular modulation , it is necessary to complete intermediate frequency signal way with appropriate intermediate frequency filter.
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