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Effect of softhandover function on effectivity of using radio sources in UMTS
Plhák, Jan ; Lambertová, Petra (referee) ; Novotný, Vít (advisor)
Bachelor’s thesis is focused on soft handover procedure in the UMTS network and its impact on the function of this network. Soft handover function allows continuous transfer of data flows, when the mobile station is crossing the border between areas which are controlled by different basic stations. This function has also impact on the performance and capacity of the whole network. This thesis describes the features of the UMTS network, soft handover principles, differences between various types of handovers and focuses on the mechanisms of the soft handover in detail. There have been several scenarios of handover procedure created in network simulation software and have been confirmed features of this function, that allows use of the lower transmission powers. On the other hand the soft handover burdens radio resources more than hard handover because of multipath propagation of the signal. To achieve the greatest soft handover gain, parameters of the network have to be set properly.
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Quality and accessability measurement of GSM network
Vondra, Marek ; Wieser,, Vladimír (referee) ; Hanus, Stanislav (advisor)
The thesis is specialized on a possibility of measuring qualities and availability of a cellular radio system and also on evaluation qualities, fruitfulness interface, permeability etc. It includes short description of a basic mobile technology. Further analysis of the possibility of measuring the mobile network and how implement the measure. It also includes a draft program for measuring and evaluation of the GSM network with help several tests by a mobile phone connected through the Bluetooth.
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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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Current security trends in mobile networks
Jirkovská, Šárka ; Sobotka, Jiří (referee) ; Doležel, Radek (advisor)
This master's thesis deals with the issue of the security of GSM and UMTS mobile communication systems. In the thesis the principles of the authentication and encryption of both the mobile systems are described. Further, the constituent algorithms used for identity verification, key generation and encryption are mentioned. The commonly used algorithms are described along with their weaknesses. In the following part of this thesis, well-known attacks on GSM system are mentioned. In the part where UMTS system is dealt with one can find the algorithms used in this system to increase the security of transmitted data and authentication in comparison with GSM system. Therefore the whole process of authentication and encryption is described separately. In the last part the creation of programming models of authentication and encryption in GSM and encryption in UMTS is described. These models are created in the environment of Matlab version 2009b.
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Data transmission in mobile networks
Bílek, Petr ; Molnár, Karol (referee) ; Havelka, Dušan (advisor)
The Bachelor’s thesis deals with mapping and usage of mobile networks of data transfers. It describes every particular generation of networks and technologies that they can use. This thesis is divided into two main parts, theological and practical. In the first part, the technologies of the second and third generation currently used for data transfer in mobile networks are described there. This concerns especially GPRS, EDGE and UMTS services. The thesis focuses on modulations used for these technologies, together with the coding and bit rates possible. It compares their advantages and disadvantages and presents their utilization among national operators. It also tries to sketch out the way the data services of mobile networks will proceed. The second part of the thesis is also divided into two parts. The first one is the simulation of the UMTS network with the assistance of the OPNET Modeller 14.5 environment. In this case, the thesis aims at two important characteristics - such as the dependence on the bit rate and distance of the primary station, and dependence on the bit rate and total load of the whole network. Both characteristics are observed mainly because of the bit rate and power characteristics. It describes objects and funcions of the OPNET environment. The next part in the practical section is the factual measurement of the Internet 4G service, provided by T-Mobile operator. The thesis focuses here on the presentation of the outcomes which were accomplished by the practical measurement of that service. The end of this thesis is dedicated to the comparasion of simulated outcomes with the outcomes practically measured, and to the conclusion of the results emerged from them.
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Analysis of parameters and communication protocols on radio interface of UMTS networks
Plhák, Jan ; Skořepa, Michal (referee) ; Novotný, Vít (advisor)
These times the third generation cellular networks are getting in use increasingly and they dramatically exceed the parameters of second generation networks. Third generation networks are in contrast to older generations data-oriented, providing better maintenance in data and multimedia services. The most widespread third generation network is the UMTS, designed as succesor of GSM network. Master’s thesis is focused on parameters and communication protocols of radio interface of UMTS network. Parameters of radio interface affect the behaviour of mobile terminal through utilization of network services. This thesis describes individual protocols of radio interface and individual procedures, which the mobile terminal have to perform through its staying in the cell. Theoretical part of this thesis considers description of the UMTS network and individual procedures and parameters. Practical part is focused on measuring the radio interface and individual procedures in real UMTS networks. Some procedures are simulated in network simulation software. This thesis includes a lab task focused on this thema.
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Wireless and mobile UMTS networks simulation using QoS
Zapletal, Lukáš ; Vychodil, Petr (referee) ; Vymazal, Michal (advisor)
Diplomová práce je psána v angličtině a věnuje se standardu IEEE 802.11e, obsahujícím podporu kvality služeb a taky pojednává o kvalitě služeb QoS (Quality of Service) v systému UMTS. Rozebrány jsou hlavní teoretické pilíře daných mechanizmů a praktická část se zabývá simulacemi síťových modelů. Standard 802.11e objasňuje propojení vrstev na fyzické úrovni a zmiňuje metody přístupu k přenosovému médiu DCF, PCF, HCF, EDCA, HCCA. Dále přístupové kategorie a také odlišnosti v MAC podvrstvě, je rozebrána problematika při přenosu prioritních dat na základě identifikátorů. Vzpomenuta je taky struktura formátu rámce a techniky s rozprostřeným spektrem. Časové limity pro doručení prioritních dat a požadavky kladené na tyto data je možné snadno srovnat v tabulkách. Problematika kvality služeb je velice komplexní záležitost, nicméně jsou rozebrány základní klíčové parametry jako koncové zpoždění, jitter, zahazování dat, propustnost, velikost front a hodnota MOS. Zmíněny jsou i mechanizmy integrovaných RSVP a diferencovaných služeb pro zajištění QoS. U systému třetí generace UMTS je objasněna architektura a společná kooperace se systémem GSM. Vzájemné propojení obou sítí je zřejmé z obrázků. Zvýšený zájem je věnován vrstvovému modelu a funkcím RRM pro zajištění QoS. Objasněny jsou různé druhy předávání hovorů, tzv. Handover Control a funkce Admission Control. Rozebrány jsou jednotlivé třídy provozu Conversational, Streaming, Interactive a Background. Praktická část se odehrává v simulačním prostředí programu OPNET Modeler. Byly vytvořeny dva modely s různými scénáři pro srovnání zajištění QoS. Model objasňující princip standardu IEEE 802.11e obsahuje dvě bezdrátové sítě s přístupovými body a stanicemi, na kterých jsou sledovány simulace s různým zatížením přenášených dat. Pro porovnání výsledků je zkoumán rozdíl při použití metody HCF v síti s podporou QoS. Model UMTS sítě obsahuje základnové stanice Node B s možností vysílání do tří sektorů. Mobilní účastník pohybující se po trajektorii představuje princip funkce Softer Handover. Konfrontace mezi scénáři je zastoupena kompresí záhlaví pomocí funkce PDCP a rozlišení Type of Service. Obzvláště je sledováno chování prioritních dat hlasu a videa u obou sítí. Naměřená data zastupují grafy a průběhy výsledních charakteristik. Analýza diskutuje odlišnosti u sítě bez podpory a s podporou kvality služeb. Rozdíly jsou porovnány a vyhodnoceny dle metodiky QoS. Součástí práce je i řešení problémů při návrhu UMTS sítě a podány jsou taky užitečné tipy a návrhy na jejich odstranění. Projekty v simulačním softwaru jsou popsány dle postupu vyhotovení, avšak hloubka podrobností je potlačena. Detaily nejsou rozebírány, protože se očekává pokročilá znalost mechanizmů a jistá dávka zkušeností s programem.
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Support of service quality demands in radio access networks of high speed variants of mobile networks
Kuruc, Jiří ; Skořepa, Michal (referee) ; Novotný, Vít (advisor)
The work deals with the developmental stages (Releases) of the third generation UMTS net-works. It explains a partial improvement from Release 99 to Release 5 and Release 6 to im-prove the quality parameters of a mobile data transmission. In the practical part, there are measured qualitative parameters of the third generation networks that are available in the Czech Republic: UMTS, HSDPA, CDMA 1xEV-DO Rev.0 and Rev.A and UMTS-TDD. The measurements give reasonably achievable data rates in both directions (downlink & uplunk), a response time, quality of VoIP calls, a dispersion, a data-loss and an ability to transmit video with different data flows. The other aspects especially an availability of coverage and end-user terminals have been assessed wihin the each network. The work is supplemeted with a laboratory, which is focused on a practical comparison of the basic parameters of data transmissions of 2G and 3G networks.
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Simulation and evaluation of scenarios running real-time UMTS services in Opnet Modeler environment
Klimeš, Roman ; Molnár, Karol (referee) ; Novotný, Vít (advisor)
This work deals with the Universal Mobile Telecommunications System problems. It researches the parameters of influencing the UMTS Terrestrial Radio Access Network behaviour where is the Quality of Services support necessary. The aim of this master’s thesis is the simulation and evaluation of scenarios running real-time UMTS services in Opnet Modeler environment. In the first part is the short introduction to this technology problem. The requirements and the aims, the frequency plan, the network architecture and the Quality of Services support in UMTS are described. Creating the mobile network in the OPNET Modeler environment, configuration of the particular elements with the correct functionality and finally the parameters configuration for the Quality of Service at all workstations was the practical part of this work. At last phase was needed to compare the final statistics of the model without QoS support and the model with QoS support. I verified my knowledge in the OPNET Modeler program and the expected simulation results were confirmed. The final part of the thesis was creating the laboratory problem on the basis experience gained.
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