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Smart Metering system
Gregor, Filip ; Pokorný, Jiří (referee) ; Mlýnek, Petr (advisor)
The thesis deals with a PLC technology. In the theoretical part a principle of PLC functionality and its advantages and disadvantages were described. In the experimental part methodology of point-to-point testing with BPL modems was designed. In addition extensive measurement according to point-to-point methodology for topology with and without repeater in laboratory was realized. Impact of repeater on transmission parameters was tested according to RCF 2544, RFC 6349 recommendation and according to methodology of TCP Throughput with the aid of Net Blazer testers and iPerf tool. The results shows that topology with repeater decreases throughput approximately 50 % and increases Round trip time (RTT) more than twice compared to topology without repeater. In the last part a laboratory task with Smart Metering system and BPL modems was designed.
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Active IP Geolocation for Verification Host Position in Internet
Balej, Jiří ; Róka, Rastislav (referee) ; Zdrálek, Jaroslav (referee) ; Komosný, Dan (advisor)
Dissertation thesis deals with methods for finding the location of the device in the Internet, based on knowledge of the IP address. The process is called IP geolocation and is currently solved by geolocation databases or by measurement of network properties to the IP address. The disadvantage of nowadays geolocation databases is an incorrect information about some locations, because they can be in large distance from correct position. The aim of the thesis is to develop a method for verification of a position from geolocation database using delay measurement. Because of it, there is a detail analysis of influence of partial delays on the distance estimation accuracy, calculated using measured delay between the landmark and the target IP address. For the same reason, long-term delay measurement was performed, where the IP geolocation accuracy was compared using calibration data from previous measurements. On this background, Cable Length Based Geolocalisation (CLBG) method is proposed. Principle of this method is built on the properties of partial delays, which depend on the length of transport media. Firstly, the method measures round trip time (rtt), which is subsequently lowered by intermediate devices and end stations delay. The geographical distance is estimated using signal speed in the transport media. Further, the winding media parameter is established, which is used to determine a constraint around the landmark. The intersection of all constraints defines the area, where the target IP is. The IP geolocation using CLBG gives better results than simpler methods (ShortestPing, GeoPing and SOI), in comparison with more advanced methods (CBG and Octant) the accuracy is similar. The disadvantage of the CLBG method is the size of region, where the target lies, but this is due to its purpose. The position found in geolocation database can be checked by evaluation if it lies in the region.
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Estimate of data strem delay during transit through network device
Dopita, Michal ; Komosný, Dan (referee) ; Verner, Lukáš (advisor)
This thesis is focused on the issue Estimation of delay during the data flow going through network device. There is analyze of network parameters, which influent final delay, detection of delay in data networks and types of delay in the network. The practil part is focused on development of the software, which performs the estimation of delay. At the end there is a summary of the whole thesis and evaluation of measurements.
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Use of optical cable properties for geolocation in the Internet
Chmelař, Jakub ; Verner, Lukáš (referee) ; Komosný, Dan (advisor)
This thesis deals with the IP geolocation which estimates the geographic location of hosts in the Internet network. The knowledge of geographic location can be used both for targeting specific services and information, such as advertisement or weather forecast, and for better utilization of transport network because it is possible to serve content from sources which are located closer to client. The main topic of this thesis is the Speed of Internet geolocation method (SOI), which is an active method based on measurement of latency in network. The theoretical part of the thesis explains how to perform these measurements and briefly describes a few more active geolocation methods. The practical part includes full description of SOI implementation created using Python programming language. This implementation was subsequently used to accomplish a sequence of measurements which allowed accuracy comparison with other geolocation methods. The final part of this thesis evaluates results of these measurements and offers a few possible changes which could improve accuracy of described implementation.
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User Interface for Web-Based Games
Hlaváč, Martin ; Beran, Vítězslav (referee) ; Hradiš, Michal (advisor)
This thesis describes challenges in designing, developing and testing web user interfaces. It discusses human-computer interaction, communication channels and user interface analogy to the real world. User interfaces can be designed to be optimal for a specific action or to suite the user. A design of interfaces focused on users utilize methods, such as gamification and improving user experience, which can improve interface usability. User interface development is demonstrated on web page development. Further, the thesis describes 3 web user interface testing methods. The methods are demonstrated by designing, developing, and testing user interface of a web strategy game.
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Location estimation of Internet nodes
Němeček, Ladislav ; Balej, Jiří (referee) ; Komosný, Dan (advisor)
This paper deals with methods of stations’ IP geolocation. It’s describes the methods of passive and active geolocation and it’s more focused on active searching methods, which usees measuring the latency in network. The factors causing delays in data transfer are discussed first, followed by discussion of the issue of measuring these delays. After that a brief description of PlanetLab experimental network, which nodes were used for delay measurment. Main topic is practical implementation of method Constraint-based Geolocation in Java programming language. Last but not least the measurement results of CBG algorithm are tested.
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Geolocation of Internet nodes based on communication latency
Horák, Michael ; Balej, Jiří (referee) ; Komosný, Dan (advisor)
This thesis covers the topic of determination of geographical location of a host in internet network while utilizing measurement of the end to end delay and implementation of Constraint-Based Geolocation. Gradually I go through issue of the delay in computer networks and ways how to measure it. Next chapter describes a few ways to geolocate host in internet network with emphasis on the CBG method. Another chapter is dedicated to describing a way to project spherical coordinates to the two dimensional space, which has been used in implementation of geolocation method. Chapter about implementation builds upon the facts given in previous chapters while functions of the program written in the JAVA programing language are being explained. Two similar geolocation methods were implemented. By comparing the results gained by implementation, new method of geolocation is proposed and devised. It combines properities of both previous methods. There are results of the implemented methods and their comparation to the one of the source documents used in creation of this thesis in summary section.
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Localization of nodes in Internet using King system
Exler, Michal ; Müller, Jakub (referee) ; Komosný, Dan (advisor)
This thesis is focus on problematics of nodes localization in Internet. There are describe methods for prediction latency by using artificial coordinates systems and by using direct measurement. This thesis is primarily focus on method names King, which is estimates latency between arbitrary end hosts by using recursive DNS queries in system for translate domain name.
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Location of node real position on the Internet
Kopeček, Tomáš ; Müller, Jakub (referee) ; Komosný, Dan (advisor)
In this thesis I focus on finding the position of computers on the Internet. This need for locating computers originated in the last several years through the creation of overlay networks. For this activity there are many algorithms. This paper describes the King method that estimated the distance between communicating stations by using the domain name system. The aim of this work is to verify the accuracy of the King method in experimental PlanetLab network. This network provides access for more than 1000 stations worldwide.
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Host distance measurement using ICMP protocol in IP networks
Fojtová, Lucie ; Komosný, Dan (referee) ; Burget, Radim (advisor)
Current internet more and more often faces the problem of the right definition of distance between the single hosts. The knowledge of this quantity influences the areas of the optimal lay-out of overlay multicast networks, the right selection of peer-to-peer network participant, or the simple decision of the end user: which one of the nearest mirrors to use for downloading datas. The nearest one doesn't have to mean the nearest in geographical point of view - the distance on Internet is usually expressed by quantities as latency or bandwidth. All these examples have got the saving of bandwidth in common and therefore economical saving. The methods of host position prediction in networks work on the basis of measuring latency parameter. The tools for measuring of this parameter will be set up in this thesis and at the same time it will be shown how geographical distance and latency correspond with each other.
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