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Mobile internet principles
Jehličková, Lenka ; Fencl, Josef (referee) ; Hanus, Stanislav (advisor)
Thesis concerns with mobile communications theory with focus on data transfer. In the introduction the history, the origin and individual mobile systems generations are described. It is followed by detailed description of second, third and fourth generation mobile systems. Frequency band allocation, signal processing, the system architecture itself, security management and basic features are also discussed. The GSM system is described together with individual data transmission types based on circuit switching – CSD and HSCSD and packet switching – GPRS and EDGE. For UMTS, FDD and TDD modes are listed as well as changes in individual releases, corresponding technologies and provided services. Next, there is the description of LTE and WiMAX systems, together with their improvements whose are part of the fourth generation of mobile systems. Last of the described systems is the still work in progress HAPS, also known as the system of stratospheric platforms. In the end important parameters are summarized and systems are compared with each other.
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Design of Communication system among Moving Vehicles
Klampár, Marián ; Polívka, Michal (referee) ; Škorpil, Vladislav (advisor)
The purpose of this thesis is to show up possibilities of inter-vehicle communication and to introduce new approaches in communication for the purpose of enhancing the security and the fluency of vehicle transportation. This thesis also highlights vulnerabilities in communication. The main goal is the analysis of existing technology and the design of protocol for data transfer with focus on minimizing handover time of informations. Part of the design is a simulation of communication based on acquired information.
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Support of real-time services in recent 3G mobile networks
Vinkler, Lukáš ; Mácha, Tomáš (referee) ; Novotný, Vít (advisor)
This Master’s thesis is focused on the recent 3G mobile networks. The first chapter describes an evolution of standardization 3G and surveys a gradual development of 3G networks in Czech Republic from a point of view of commercially launched technologies and assigned frequency spectrums for single mobile operators. UMTS and CDMA 2000 are briefly approached in next subchapters. The subchapter CDMA 2000 is briefly concentrated on architecture and a physical layer of this technology and characterizes main features of four revises of developmental branch CDMA 2000 1x EV-DO. The subchapter UMTS is especially focused on a comparison of air interfaces TD-CDMA and W-CDMA. New features were implemented to the recent system UMTS for a better support of real-time services. These features increasing a throughput and decreasing a delay are described in a chapter Technology HSPA. This chapter chooses the most important features and describes changes (in a control and architecture) which had to be implemented. First chapter is finished by technology WiMAX. The most recent perspective cell systems are compared with WiMAX in this subchapter and qualitative parameters of WiMAX are shown there. The three different 3G technologies (UMTS-FDD, UMTS-TDD and CDMA 2000) are lunched in Czech Republic. The second chapter briefly compares coverage of three czech mobile operators (Telefónica O2, T-Mobile and U:fon) and then presents results of qualitative parameters of used 3G technologies. The simulation conducted by software IxChariot were focused on to gauge parameters like throughput, delay, jitter, lost data, MLR and DF. The conditions for providing real-time services were specified based on simulations that were practically checked. The lab composed in last chapter should bring closer to students technology UMTS-TDD launched by T-Mobile. The students will measure the qualitative parameters of this technology with the assistance of commonly available tools.
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Integrated telecommunication environment
Tomeček, Jan ; Škorpil, Vladislav (referee) ; Polívka, Michal (advisor)
The thesis described the proposal for a wireless network problems. There are recorded and compared the characteristics of different wireless technologies. The possibility of voice communication securing is outlined and solutions implemented in the form of ZRTP protocol. The requirements for quality of service are discussed and the solutions to this issue are proposed. Other chapters are devoted to the actual design of specific equipment, including antennas and advance resource. The whole network is practically implemented in the mountainous countryside of eastern Wallachia. In conclusion, this work is network mate in terms of QoS (quality of service) and tested in terms of prioritization of voice communication.
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High bit rate LTE mobile system
Ohera, Vlastimil ; Kejík, Petr (referee) ; Hanus, Stanislav (advisor)
Aim of thesis was to acquaint with architecture and process of signal in systems using broadband LTE wireless technology. Thesis in detail is described physical layer of system. Next there is described comparison of LTE and WiMAX and table with all present systems. Thesis also is contained information about tested LTE system in real traffic. Next aim was created simulation of LTE system in downlink and uplink. Interface was created for easier configuration of each characteristics of transfer and type of interference of useful signal. This interface is contained control of whole simulation and presentation of measured values. Measured data were processed into graphs, which show dependence of error rate BER on C/N of useful and interference signal.
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Minimizing the effect of interference on wireless network
Doležal, Jan ; Kyselák, Martin (referee) ; Škorpil, Vladislav (advisor)
This thesis is concerned the technology with technologies of transfer through wireless devices. It is about possibilities of optimization of transfer in wireless net, especially of the reduction of interference influence. The first part is about theory and the standards development of wireless technology. There are methods and principles used in wireless technologies. The second part is a practical measuring and testing of an internal wireless net, with the emphasis being on the source of interference influence. Measuring was focused on interference between access points and was not about meteorological influence. It continues with theory and testing of interference of the microwave oven in our wireless net. Then, it is a practical demonstration of interference in an external environment. There are practical examples of interference between different providers’ nets on the same area and solutions to prevent or to cancel this interference. In next part of work the wireless net is parsed and described in a given territory. Here is described the way how to precede the reciprocal interference and eventually how this mutual disturbance suppress. Consequently, our net is optimized for customer growth and for today’s options of newer and more powerful components for wireless transfer. Finally there are two laboratory tasks. The first one is about practical measuring and testing of wireless net’s parameters and the second one is about simulation of wireless networks in the Opnet program.
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Problem of security wifi nets
PŘITASIL, Miroslav
This diploma thesis describes the secure wireless data transfer mediated by various technologies. A special attention is given to standards 802.11x, different kinds of technologies protection originating of the standards and to possible attacts targeted against them. Moreover, it deals with the problems related to password and sensitive data protection which are important to the network administration. The thesis gives also some examples of particular network type securing.
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Development and Future Prospects of Mobile Internet Connection in the Czech Republic
Bičík, Petr ; Toman, Prokop (advisor) ; Dudová, Lenka (referee)
Mobile telecommunications belong to one of the fields which still evolves and it is expected that in the future they are going to offer great benefit to the whole world. This work focuses on current and future development of mobile Internet connection in the Czech Republic. At first the technologies used to provide mobile Internet connection are described and compared and then the situation (in terms of technologies and mobile operators) in the Czech market is outlined and its possible evolution in the near future is presented. Furthermore, the tarifs of mobile operators are compared with those in place two years ago. The strengths and weaknesses of the current mobile Internet connection are evaluated based on the conducted questionnaire survey. The latest results are then analyzed and compared with the results from a previous survey conducted in 2007 as part of a bachelor's thesis, which has been further extended in this mater's thesis.
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Internet connection for mobile users
Špírek, Martin ; Pavlíček, Luboš (advisor) ; Gála, Libor (referee)
In this work I am writing about more and more occurring phenomenon, which is opportunities to connect to the internet for mobile users. I am describing and comparing technology to serve those internet users who need to connect from different locations, or require a connection to the internet on their travels. In the first part of thesis I am explaining the most important and frequently occurring terms, which will help to better understanding and orientation in other parts of the work. The chapter "Definition of basic terms" is followed by chapter "Wireless technology connection" in which are described in greater detail the various technologies available for wireless internet connections and also the advantages and disadvantages of this connections. The second part of my work is focused more practical. There are mentioned real possibilities how to connect wireless to the internet available in the Czech Republic and they are compared with each other. There is also a comparison of mobile operators and their services, which are involved in providing internet access. I tried to also explain here what type of connection is suitable for whom. There are also given here the results of the measurements of speed and quality connection provided by mobile operators. The goal of my work is to acquaint readers with in these days very different wireless options how to connect to the internet and their basic characteristics and then comparing these technologies to facilitate the selection of potential users for the best type of connection.
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Možnosti vysokorychlostního připojení k internetu pro vybranou organizaci
Kinská, Marcela ; Toman, Prokop (advisor) ; Kubíček, Jovan (referee)
Tato práce si klade za cíl seznámit čtenáře s problematikou implementace vysokorychlostního připojení k internetu v podmínkách malé až střední organizace (SME). Poté, co čtenáři přiblížím technologie vysokorychlostního připojení vhodné pro nasazení v podmínkách SME, následuje hlavní část mé práce tvoří tématická oblast internetu v organizaci, obsahující možnosti využití vysokorychlostního připojení k internetu, tzv. služby internetu, stejně jako metodiku jeho výběru, kterou považuji za vlastní přínos své práce. Teoretickou část této práce jsem pak rozšířila o případovou studii. Na příkladu z praxe, reprezentovaného středně velkou organizací, uvádím nejen parametry současného i předchozích řešení vysokorychlostního připojení k internetu, ale analyzuji zde i současný stav využití internetu v organizaci. Praktickou část mé práce v závěru doplňuji o konkrétní doporučení, jak využití vysokorychlostní přípojky v podmínkách zkoumané organizace zefektivnit. Vycházím přitom ze znalostí nabitých v průběhu studia odborné literatury.
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