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PLC system for Smart Metering
Bijotová, Kateřina ; Sláčik, Ján (referee) ; Mlýnek, Petr (advisor)
This thesis deals with PLC communication, presents pros and cons of this technology. The thesis describes several basic standards of the narrowband communication and broadband HomePlug AV2 standard. It groups the technology according to frequency band. Also, it brings summary of commercial products and development kits which are using PLC technology. The thesis contains the description of network testing to RFC 2544 recommendation and its application onto narrowband Linksys PLEK500 modems using NetBlazer tester which took place in laboratory of Brno University of Technology’s Department of Telecommunications. The same PLC modems are used in a second series of experimental measurements in home environment. This thesis also deals with comparison of narrowband PLC standards PRIME and G3 whilst exposed to different transmission conditions as defined by pre-established measurement scenarios. Said comparison was attained by measurements using Atmel’s multi-carrier PLC kit SAM4CP16C-EK. In the closing section of the thesis the results obtained by said measurements are consulted with conclusions provided by contemporary PLC-oriented publications.
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Security Protection efficiency improvement for Wireless Networks
Marušek, Michal ; Burda, Karel (referee) ; Škorpil, Vladislav (advisor)
Nowadays every wireless radio-communication services encompass huge type of technology used for transfer video, voice or data. Wireless communication is the most expanded branch and many companies are using this technology because of low cost and simply management. The biggest advantage is easy connection to shared wireless medium and allows users of network to move around whole covered area. The most expanded types of wireless networks are called Wireless LAN (WLAN). With rising number of WLANs is rising chance to attack shared wireless medium by hacker and many sensitive information can be stolen or modified. To avoid this chance was created the first security protocol used in WLAN called WEP. Its goal was protect data transmitted trough WLAN as strong as were protected in wired networks. Unfortunately WEP was hiding a big weakness which can be used in a crack of WLAN in a minute with the aid of special software. Example of this kid of software can be Airsnort constructed to monitor shared medium and captured every packet transferred trough this medium. Based on statistical method Airsnort can obtain hidden password in a few minutes. The second type of this software can be Aircrack-ng, which can crack hidden password without any user connected to WLAN. Aircrack-ng uses active techniques to generate network load and can obtain password more effectively and faster. The result of both cases was successful and protection of WLAN was completely cracked. Later was created new security protocol called WPA, which had to fix the cryptography weakness of previous WEP. WPA was only temporary security protocol, during standard 802.11 was developing which had to offer highest security and integrity protection of transferred data trough WLAN. For this reasons was created new version of WPA called WPA2 which satisfy requirements of standard 802.11i. Both protocols WPA/WPA2 contain weakness, which can crash security of WLAN. This crack is based on authentication PSK. Attacker during authentication is using information from four-way handshake between user of WLAN and access point. Based on this information attacker can crack password with the aid of password list attack which took approximately 30 minutes. Based on previous result is important to chose strong password contains alphanumeric string or special strings with satisfy length.
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Analysis of digital modulation robustness at various types of interference
Uher, Tomáš ; Šilhavý, Pavel (referee) ; Kubánková, Anna (advisor)
This bachelor thesis concisely describes essential type of modulation technique for transmission of binary signal. In first part there are summarized advantages and disadvantages for each described modulation technique. There are described proceeding of modulation and demodulation too. Selected digital modulations are tested for Gaussian, Rice and Rayleigh transmission channels. In final part there are compared theoretical and measured values and summarized analysis.
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Model of communication system with the PLC channel
Kovařík, Tomáš ; Krajsa, Ondřej (referee) ; Mlýnek, Petr (advisor)
The aim of this work was to develop a model of a communication system with the PLC channel. The model contains different types of modulations with the possibility of their settings. The impact of a disturbance on different numbers of states QAM modulation has been evaluated. The theoretical part describes the PLC technology with its functions and the most widely used narrowband modulation.
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Design of new laboratory exercises in the course Access and transport networks
Ťupa, Martin ; Kyselák, Martin (referee) ; Škorpil, Vladislav (advisor)
In my final project there are proposed two new laboratory tasks for the subject Access and transport network. These tasks are focused on the problem of shift keyings. There are a lot of types of shift keyings, however, I directed my attention at the following ones – the Amplitude shift keying ASK, the Frequency shift keying FSK and the Phase shift keying PSK. I used TutorTIMS training system for measurement and observation. The aim of my final work is to collect both practical and theoretical information based on the shift keyings and help the Access and transport network students in the future.
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The Influence of Modulations in optical networks based on OTDM
Kočí, Lukáš ; Šifta, Radim (referee) ; Münster, Petr (advisor)
The bachelor thesis inquires into influence of modulations to transfer in optical nets, with the 320 Gbit/s zone width, based on the OTDM principle. There are also explained effects impacting on the signal transfer by optical fiber, single-mode and multi-mode op- tical fibers are described here and also principles of used technologies of multiplexing are explained. There is compiled the proposal of transmission system, which is subsequently simulated in the OptSim programme. On the initial simulation model there are the mo- dulation formats tested progressively, patterned on theoretic knowledges and its influence on the transmission quality is evaluated.
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QAM Modulator
Duffek, Luděk ; Kubánek, David (referee) ; Číž, Radim (advisor)
The thesis focuses on consideration of possible ways how to realize multi-state modulators for a laboratory instrument. This instrument will illustrate signals, which partake on generation QAM modulation. The design of the laboratory instrument includes theoretic schemata and the execution of a prototype. There are theoretical facts of multi-state signals and multi-state modulations in this thesis. A simple block diagram of the laboratory instrument is made by the theory of creating quadrature amplitude modulation. For each block there are made several schemata, which are compiled to the global scheme. A printed circuit board and the structure items are made by the aid of the global scheme. The next part is devoted to a software facility for a used microprocessor, which ensures the whole function of the laboratory instrument. The final section deals with measuring, which checks the function of the modulator and the right setting coder’s constellation diagrams.
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Analysis of digital modulation robustness at various types of interference
Uher, Tomáš ; Šilhavý, Pavel (referee) ; Kubánková, Anna (advisor)
This bachelor thesis concisely describes essential type of modulation technique for transmission of binary signal. In first part there are summarized advantages and disadvantages for each described modulation technique. There are described proceeding of modulation and demodulation too. Selected digital modulations are tested for Gaussian, Rice and Rayleigh transmission channels. In final part there are compared theoretical and measured values and summarized analysis.
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PLC system for Smart Metering
Bijotová, Kateřina ; Sláčik, Ján (referee) ; Mlýnek, Petr (advisor)
This thesis deals with PLC communication, presents pros and cons of this technology. The thesis describes several basic standards of the narrowband communication and broadband HomePlug AV2 standard. It groups the technology according to frequency band. Also, it brings summary of commercial products and development kits which are using PLC technology. The thesis contains the description of network testing to RFC 2544 recommendation and its application onto narrowband Linksys PLEK500 modems using NetBlazer tester which took place in laboratory of Brno University of Technology’s Department of Telecommunications. The same PLC modems are used in a second series of experimental measurements in home environment. This thesis also deals with comparison of narrowband PLC standards PRIME and G3 whilst exposed to different transmission conditions as defined by pre-established measurement scenarios. Said comparison was attained by measurements using Atmel’s multi-carrier PLC kit SAM4CP16C-EK. In the closing section of the thesis the results obtained by said measurements are consulted with conclusions provided by contemporary PLC-oriented publications.
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The Influence of Modulations in optical networks based on OTDM
Kočí, Lukáš ; Šifta, Radim (referee) ; Münster, Petr (advisor)
The bachelor thesis inquires into influence of modulations to transfer in optical nets, with the 320 Gbit/s zone width, based on the OTDM principle. There are also explained effects impacting on the signal transfer by optical fiber, single-mode and multi-mode op- tical fibers are described here and also principles of used technologies of multiplexing are explained. There is compiled the proposal of transmission system, which is subsequently simulated in the OptSim programme. On the initial simulation model there are the mo- dulation formats tested progressively, patterned on theoretic knowledges and its influence on the transmission quality is evaluated.
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