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Effective utilization of converged network
Nesveda, Marek ; Vychodil, Petr (referee) ; Škorpil, Vladislav (advisor)
The Master´s thesis deals with the field of converged networks and their effective utilization, focusing specifically on telematic networks. For modelling of a specific application, the field of vehicle telematics has been chosen. The thesis consists of two series of simulations performed in Opnet Modeler network simulator. The first theoretic part gave an overview of protocols used in converged networks, with a more detailed description of routing protocols. The attention also centred on the mechanisms for assuring the quality of service in IP. The subsequent practical part consisted in creating the simulation of a converged telematic network in Opnet Modeler network simulator, configuration of scenarios for assuring QoS using RSVP and DSCP protocols and the simulation itself. The results of the simulations for both scenarios were compared and represented in graphic form. The second theoretic part described queueing disciplines, as well as congestion control and congestion avoidance mechanisms. The corresponding practical part compared FIFO, PQ and WFQ queueing algorithms within the same simulated converged telematic network, using DSCP protocol scenario, which gave much better results in the first series of simulations. Again, the results of the simulations were compared and represented in graphic form.
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Quality of service assurance using the MPLS protocol
Henzl, Václav ; Novotný, Vít (referee) ; Hošek, Jiří (advisor)
The aim of this semestral thesis is to create a MPLS network model using OPNET Modeler program and consecutive simulation of this network behavior with focus on quality of service assurance. This project contains also theoretical introduction to the MPLS network problematic and quality of service assurance - hereafter it is focused on simulation and analysis of data flows in extended communication network model with focus on Voice Over IP parameters. This thesis is discovering attributes of MPLS with respect to network traffc.
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Generation of data units in OPNET Modeler environment
Mikulica, Vladimír ; Skořepa, Michal (referee) ; Hošek, Jiří (advisor)
This dissertation deals with the generating of data units at different levels of TCP/IP network model in OPNET Modeler environment. A part of the dissertation is a brief introduction to the simulation environment OPNET Modeler where important components of this comprehensive simulation software are elucidated. The structure of my dissertation reflects individual layers of the model TCP/IP, whereas the function of the process model OPNET Modeler and the data unit used at corresponding levels of TCP/IP is always described. Particular parts of communication models that were created in the simulation environment OPNET Modeler at selected layers of the network model TCP/IP are closely documented in each chapter. Relevant scenarios are described in such a way that they can be later re-arranged by eventual customers.
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QoS assurance in wireless networks
Kolmačka, Jan ; Vychodil, Petr (referee) ; Vymazal, Michal (advisor)
The diploma thesis gives the overall information about the field of wireless networks of standards 802.11 and Quality of Service (QoS). The practical measurements describe the reactions of multimedia dataflows in the networks 802.11a/b/g/n. The individual standards, offered services, access methods and the network architecture are analyzed in the theoretical part. In the following part there is written about QoS and its basic parameters. Moreover, the standard 802.11e and the question of QoS in the wireless networks are explained in a detailed way. The first part of the practical measurement is focused on the networks 802.11b/g/n. All main network statistics are measured when using the wireless stations and routers. The projection and implementation of the wireless network in the Opnet Modeler is included in the next part. The individual simulations WLAN in the Opnet Modeler are comparing the networks 802.11a/b/g. The analysis of the key QoS statistics is undertaken; the measured data are clearly displayed in the charts and schemes. The interpreted results are concluded and justified.
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QoS simulating of wireless network in OPNET
Rágula, Michal ; Molnár, Karol (referee) ; Vlach, Jan (advisor)
The aim of this bachelor work is project and simulation of wireless network with the Quality of Service (QoS) support. It is composed of two parts, the theoretical and the practical one. In the first part there are analyzed findings needed for understanding the existing problems. The second part describes project in detail and setup of network. The theoretical part presents division and format of wireless networks, especially Wi-Fi settings, which is defined by IEEE 802.11 standard. The biggest attention is paid to IEEE 802. 11e standard, which improves the so-called Media Access control MAC (sublayer of line layer) with extension of the QoS (Quality of Service) support in wireless local networks. This standard is important for delay sensitive applications like Voice over Wireless IP and current multimedia. The practical part describes design of wireless network in Opnet Modeler settings and configurations of particular components for the right utility. The required quality of service (QoS) support is achieved by authorization of HCF (Hybrid Coordination Function) protocol at all operating stations and AP access points. It was necessary to make two models. First of them supported the QoS service. On the other hand the same service was inaccessible for the second one. Statistics are made by comparison of final graphs of these two models.
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Design and implementation of model architecture of MIB system database
Mikulica, Vladimír ; Hošek, Jiří (referee) ; Molnár, Karol (advisor)
The submetted work deals with the systems design and the implementation of the model database MIB. The work is the introduction into the protocol SNMP (Simple Network Management Protocol) and the database MIB (Management Information Base), which describes in detail branch MIB II. This branch is the current standard for the management of objects using SNMP. Consequently, there are explained different data types that the MIB database uses. Furthermore, the work describes the procedures for the design of the database MIB in the language of ASN. 1 according to RFC 2233 and the subsequent transfer of the MIB database, available through the compilers into the langure C. In the following chapters of the work, each of the models that were created in the simulated environment OPNET Modeler during the implementation of a comprehensive simulation scenario are documented more in detail. The above mentioned parts implement the communication between the manager and the agent. The state machine and the individual blocks of the model are described so that it could be later re-assembled by other candidates.
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Efficiency of Wireless Networks from Services View
Buchta, Marek ; Vymazal, Michal (referee) ; Škorpil, Vladislav (advisor)
Subject of this thesis was the issue of effectiveness of wireless networks from the perspective of services. Become acquainted with WiFi network standard IEEE 802.11 with protocols and principles of WiFi networks and services. It should be focused on the quality of service QoS. In teoretical part of this thesis are described problems considering wireless networks, layer model and types of nets used in WiFi. Standard IEEE 802.11 is analysed in details including supplements and used packets. Special attention is paid to the quality of service QoS. Next are discussed the principles and application services as VoIP, videoconferencing, video streaming and others in WiFi network. On the basis of obtained knowledge is designed extensive WiFi network with assured supply of services. For modelling and simulation of wireless network is used software development environment Opnet Modeler. Model of wireless network is used to optimize and analyse this wireless communication network. In thesis are also simulated properties of data which are sensitive to delay. In last part of thesis is created a laboratory work, which contains a submission of task, detailed theory, wiring diagram, instructions for elaboration, guidelines for simulation and example of elaboration of task. Work is about comparison of network with used 802.11b and 802.11e standard, and support of quality of service QoS.
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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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Administration and configuration of simplified database QoS MIB
Macura, Miroslav ; Matocha, Tomáš (referee) ; Hošek, Jiří (advisor)
The main aim of this work was to study the issue of the SNMP protocol and MIB database in order to focus on management and configuration of MIB database using the SNMP protocol. The Master's thesis in detail describes especially creating a communications model of the Manager - Agent type in an OPNET Modeler. In this modeling tool we created exchange of information from the side of the Manager to the side of the Agent via SNMP packets. The Master's thesis is mainly focused on the creation of the SNMP packet according to defined rules, then on reading of information from the MIB database on the side of the Agent and saves this information to the Manager’s MIB database. Exchange of informations is realized via the messages of type GetRequest, GetNext and GetResponse. These models are programmed in language C/C++ and then implemented into the environment of OPNET Modeler.
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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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