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Power-line data communication
Šádek, Michal ; Mlýnek, Petr (referee) ; Mišurec, Jiří (advisor)
This master's thesis describes a principle of the systems for data communication over powerline. The frequency we can divide to narrowband and broadband. Various modulatory techniques with their usage and access method technology according to norms are mentioned. Engineering constraints as are frequency subband and sources disturbance are mentioned. A conception laboratory net is designed, where are effected trial measurement in data communications for systems ModemTec, Homeplug AV a DS2. This demonstration of communication contains display communications spectrum of choice systems and their matching. To comparison is used synthetic created nets LISN (Line Impedance Stabilizing Network) in narrowband transmissions. Long - term metering of systems ModemTec is is effected in laboratory net VUT and in the working condition in Swiss extension companies Daetwyler Rubber where are produced robust rubbery production. System DS2 is measured in home network, where are supposes low disturbance and in industrial environment company Daetwyler Rubber. On the basis report information of phase quality recorder a powerline and measured rate of communication, it is evaluate an influence disturbance on a data transmission and response time. At the close are mentioned principles of usage this communication.
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Optical connection
Horák, Jaroslav ; Mišurec, Jiří (referee) ; Káňa, Ladislav (advisor)
Master's thesis treat of optical connection. The aim of this work was also the practical implementation and successful testing. Communications signal is low frequency in the range of 20 to 15 kHz and intended length of the coupling is approximately 200 m. The first is the work carried out theoretical analysis issues. Then is described the design and implementation of its own facility. In conclusion, the measurement is done and evaluate the parameters. I have dealt the optical connection with using a laser beam that is modulated frequency modulation. This optical signal is converted in the receiver using a PIN photodiode (type PIN) back to the electrical signal. Then there is the demodulation and amplification. The frequency modulator and demodulator is phase lock loop. It realizes the type of circuit CMOS 4046. The work is designed properly functioning equipment. It serves for the transmission of speech and audio signal line. It has good properties that match the criteria. The connection can be used outdoors due to the use of cover. The scope of communication may be even greater than 200 meters
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Narroband PLC model
Sekot, Karel ; Krajsa, Ondřej (referee) ; Mišurec, Jiří (advisor)
This thesis is focused on data communication utilizing low-voltage power distribution lines (PLC). It describes interference in narrowband systems commonly used for remote data collecting, for example. Preamble deals with basic priciples of PLC (signal injecting) and describes the measuring workplace, its wiring and used tools. Following sections define different types and possible sources of interference, operation of the equipment in terms of EMC and other characteristics of the transmission path. The text also analyzes practical interference tests, identifies main parameters affecting data transmision and compares teoretical and practical conclusions.
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LAN communication unit resistivity against Internet origination attacks
Valach, Michal ; Mlýnek, Petr (referee) ; Mišurec, Jiří (advisor)
This thesis is focused on crypto-module RCM 3700, which is used for encrypted data transmission. Following work analyses basic network protocols and some sort of attacks in Ethernet network. The main goal of these attacks is to collect information and services about the device and to analyze transmitted data. Based on these information attacks can be done more precisely than without them. The main target of these attacks is the denial of particulary service or data abuse. Furthermore, in the diploma thesis configuration of router CISCO 2801 is applied in order to improve the LAN security. The deveploment board, which includes reset function, supplied circuit and interface for RS 232, was designed for crypto-module RCM 3700.
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Design of PLC network for remote data acquisition
Šebela, Miroslav ; Zeman, Václav (referee) ; Mišurec, Jiří (advisor)
In thesis is according assignment realized PLC (power line carrier communication) network design for remote data collection. To understand problematic of PLC is this technology described little bit in detail. In thesis are mentioned possibilities use broadband and especially narrowband power line carrier communication. Described is also general structure of PLC network for data collection - automatic meter reading. Finally is described realization of PLC network on chosen area included component supplier selection. In thesis is also mentioned problematic of PLC a communication channel included problems with noise and channel impairments. With selected PLC modems was realized and evaluated measurement of communication speed in different environments and with use of different interfaces. Furthermore was measured spectrum of communication signal from which was possible to define signal modulation. In last step were measured impairments in powerline.
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Data transmission over distribution power networks
Vašíček, Filip ; Mišurec, Jiří (referee) ; Zeman, Václav (advisor)
This thesis brings together information about the data transmission over distribution power networks with a view to the broadband systems. The division of PLC systems is mentioned and the principle and characteristics of PLC technology are described. I was also interested in topology and a description of elements of PLC network. There are presented the two most frequently used systems: HomePlug and DS2. Next section contains an analysis of network architecture, especially the physical layer. The protection of data against errors and the OFDM method are described. There are also analyzed other layers of the network reference model, the mechanism of quality of services and the data encryption using AES. I was also focused on the issues of standardization of PLC, the electromagnetic compatibility and a description of the international project OPERA. In the practical part is processed the concept of the laboratory PLC network with elements of the system Defidev/DS2. Functionality of the network has been tested by measuring of the bit rate on the physical and application layer.
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System for testing the robustness of communication unit LAN of remote data acquisition
Mlýnek, Petr ; Zeman, Václav (referee) ; Mišurec, Jiří (advisor)
Remote data collection systems are widely used. One of the area is also data collection in energetics, where the energy consumption can be collected daily and presented to users on-line. The advantage of the remote data collection is possibility of frequent readings without a physical presence at the electrometers. The data transmission over the Internet can be subject of various attacks, which is the disadvantage. The understanding of attack method is the most important thing. The protection against the hackers is not complicated, but requires lot of attention. This master's thesis is focused on testing security of the communication unit LAN of remote data acquisition against attacks from the Internet. The next aim of this thesis is to describe algorithm of particular attack, needed recourses for their realization and method of their measurement and evaluation. Communication unit and component composition for attacks simulation is described in the first part of this thesis. The next part is focused on scanning for hosts and ports. The main part of this thesis is focused on the denial of service attacks and man in the middle attacks. In the end of my thesis is described selection of cryptographic system for remote data acquisition and is showed possibility of authentication mirroring. Problems of physical security are described too. The result of this thesis is script implementing all attacks, which are described.
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Interference modelling for xDSL
Čermák, Josef ; Mišurec, Jiří (referee) ; Zeman, Václav (advisor)
This work is focused on the subject of the interference modelling for xDSL technologies. First, the xDSL technologies are explained. Following is the presentation and description of the different kinds of the xDSL technologies. The next part deals with the basic parameters of metallic cable lines – especially the primary and secondary parameters. Nowadays wider bandwidths are used for the achievement of higher data transmission rates. During a higher frequency signal transmission a more intensive line attenuation appears. To identify the transfer characteristics of the lines while using an xDSL system, mathematic models of transmission lines are applied. That is why these mathematic models are dealt with in the next chapter. At the end of this section the mathematic models are compared using the modular and phase characteristics. The main aim of the work is to describe the different impacts which influence the efficiency of the xDSL systems. First, the causes interfering from the inside of the cable are deeply explained: Near End Crosstalk (NEXT), Far End Crosstalk (FEXT), Additive White Gaussian Noise (AWGN). Following is the explanation of the external interfering impacts: Radio Frequency Interference (RFI) and Impulse Noise. The next goal of this thesis is a design of a workstation for the tests of spectral features and the efficiency of the xDSL systems. The work also presents a designed GUI application and its description. The GUI application is an instrument for the choice or data entry of the final interference. The last chapter describes a realization of a measurement and shows the measured characteristics which were recorded on the ADSL tester and oscilloscope.
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Wideband methods of data transmission over power networks
Svoboda, Pavel ; Mišurec, Jiří (referee) ; Zeman, Václav (advisor)
The aim of this work was to peruse and desribe the high-speed data technology communicating over energy network. In this work was investigated broadband system communicating over low power distribution network. The laboratory network was designed for measuring parametres of this communication and performed set of tests. Lended devices were described, properties of technology specification and methods of connection and management were introduced. Management, configuration and measuring over web interface on the NMS device was described and simple dividision into corresponding functional blocks corresponding to structure of web bookmaks was made. Metodology of individual tests, grounded on documentation “recomandation” RFC and on introduced works, was elaboratly described. Used tools, their properties and managements were described. The transmission speed on application and physical layer were followed primarily, frequency dependencies on signal noise ratio and bits per carrier were followed secondary. Measured results from individuals tests were compared among each other and evaulated. This observation leaded into decision on needed criteria for varius application. The suitaibility for integration into communication network for maintaining corresponding QoS was appreised. Testing and chosen types of tests in this project were standardized and integrated into ITU standard. Individual tests are able to compare from the view of their testify charactestic.
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Methods for measuring the bit rate on the Internet
Pilčík, Jan ; Mišurec, Jiří (referee) ; Zeman, Václav (advisor)
Due to a signifikant development of computer networks in the last few years the demands for measurement of network metrics increased. This master´s thesis is dealing with standards for testing and test techniques used for the measurement of network metrics. Further it compares the existing free accessible measurement tools and metrics measures them. Finaly the thesis draws up a web application for measurement of the basic network metrics.
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