|
|
Modelling of PLC system to ensure the reliability of communication
Procházka, Vít ; Mišurec, Jiří (referee) ; Mlýnek, Petr (advisor)
The master´s thesis is focussed on principles and characteristics of Powerline Communications (PLC), practical usage possibilities and advantages and disadvantage of it. There are described mudulations and a channel encoding which are in PLC used. The main part of the thesis deals with a design of a channel as transfer function through the use of two methods, an echo model and the ABCD matrix. After finishing of the design of transfer function the model of communication was created in the Matlab-Simulink program. There were used the narrowband modulations in the model and analyzed the bit error rate of the tranfer data. In the end all results were treated graphically and evaluated.
|
|
|
Secure converter for an RS-232 standard to the Internet
Pokorný, Michal ; Mlýnek, Petr (referee) ; Koutný, Martin (advisor)
Master´s thesis tries to find a solution to make a secure transmission channel between virtual serial ports on the personal computer and the serial ports on the Rabbit RCM3700 development KIT. Today’s communications channels don't offer appropriate security of a whole communication. Therefore it depends on get-togethers, in order to realize this security themselves. This security means ensuring reliable transmission of data to be encrypted between parties so that any attacker is not able to read real-time, or eventually change them. As a result of this Master thesis is the design and implementation, which in addition to encryption algorithm provides sufficient security and authenticity of communication between the parties. As an encryption algorithm has been chosen widely used AES algorithm and as authentication algorithm has been chosen algorithm, which for authenticity requires knowledge of the secret key.
|
|
|
Optimization of data communication over high-voltage lines
Minárik, Peter ; Krajsa, Ondřej (referee) ; Mlýnek, Petr (advisor)
The thesis deals with analysis of the PLC (Power Line Communication) system for data communications through powerlines. In the introduction describes the technology of data transmission through the energy network and is divided into categories corresponding with the explanation of the various specifications and features. Different types of coding, affecting the transmitted signal interference and modulation techniques used in a PLC are also described. The practical part is made up of telecommunications network model with transmission channel realized as additive white noise. The model can setup different types of modulation and coding in relate with the signal to noise ratio and bit error rates. The individual blocks settings are described in detail. The model was simulated. The results of simulation are displayed and evaluated at the end of work.
|
|
|
Implementation of computer models of lines for PLC
Mrákava, Petr ; Mlýnek, Petr (referee) ; Mišurec, Jiří (advisor)
The subject of this thesis is to become familiar with the different parameters describing the lines, and the possibility of modeling data and power models. The thesis also outlined the difference in the mechanical structure of different types of cables. The practical part focuses only on the power cables and measure their basic parameters. Then is created computer model which describes the behavior of cable lines at higher frequencies than are primarily intended. The final section is an experimental network created by the PLC for remote reading of electricity meters, and it measured different transmission properties.
|
|
|
Remote data acquisition over the power lines
Neuschl, Martin ; Koutný, Martin (referee) ; Mlýnek, Petr (advisor)
The subject of this paper is „remote data acquisition over the power lines“. The first part is engaged in characteristics of power lines. The other part considers PLC technology, its properties and usage. Base on disturbance and noise in power grid is chosen optimal modulation technique and error handling for PLC. The next part describes options of authentication. It has been designed secure way of authentication for data collection over power lines and attack-resistance is considered as well. Practical purpose is dedicated to simulations and noise measuring during communication of narrowband PLC modems. It deals with long-term power grid testing and its influence on transmission rate between PLC modems and also with the influence on primary parameters of power grid. Packets are investigated during communication as well.
|
|
|
Modelling of Power Line Communication for data transmission
Kadlček, Václav ; Mišurec, Jiří (referee) ; Mlýnek, Petr (advisor)
Thesis deals with problems PLC (Power Line Communication) communication. It is aimed at drawing up a suitable model for testing power network PLC communication. The reader is aware of at the beginning of work with the basic principles of PLC systems, distribution and use in communication networks. Another part of the work deals with different types of interference, which occur in power networks and ways to defend against such interference. For example, an appropriate choice of modulation and coding relevant. As a source of interference in the proposed model is used AWGN channel (Additive White Gaussian Noise). Conclusion of work is dedicated to design and build a model for PLC communication. There are three models designed with different OFDM technology. Models therefore vary between different levels of key mapping in OFDM (QPSK, 16-QAM, 64-QAM). It made a detailed description of a set of blocks that were used to build models. The behavior and functionality of the proposed models for broadband PLC communication was verified in the simulation program Matlab Simulink. Finally, it is shown the comparison and evaluation of results of each modulation.
|
|
|
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.
|
|
|
Implementation of network protocol into network simulator 2 environment
Janiga, Robin ; Mlýnek, Petr (referee) ; Koutný, Martin (advisor)
This thesis describes a protocol for the multiple data collection system and his implementation into Network Simulator 2 environment. The system defines two communication units. CU central unit and measuring unit MU. The units operate according to the rules defined by communication protocol. The content of this work is as follows. At the beginning is described the simulation tool, namely a system NS-2 and a tool for visualization of simulation results, the NAM. This is followed by a description of the proposed protocol, his principle of functions, units description and communication messages. The method of communication between units. Mainly was described the multicast and the types of multicast ASM and SSM. Additionally, was described the principle of unicast communication. This is followed by chapter describing methods of enlargement simulator. Adding an own protocol and support of multicast communication SSM. Adding a new protocol is represented by programming a new agent, a new application and a new protocol header definition. In this chapter are also described the necessary changes in the source files that are need to the recompilation. The main objective of this thesis is own implementation of the proposed protocol. In the programming language C++ were created two agents who represent a central and a measuring unit. These agents were compiled into a simulator and by using a simple script have been tested for functionality. The simulation script define MU 200 and one unit CU. Conclusion of work is devoted to simulation the load line between the central unit and "access" node. It was examined whether the use the method of cumulative acknowledgement saves the transmission capacity of line compared to normal method acknowledgement.
|
|
|
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.
|
|
|
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.
|
guest ::
RSS feed.