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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Modelování řízeného využití síťových zdrojů v sítích UMTS / Modelling of UMTS network resource control

Bednárik, Ján January 2009 (has links)
The main aim of my master thesis was to get acquainted with the implementation of quality-of-service support methods in UMTS 3G mobile network and the evaluation of these methods in a simulation environment with main interest in the characteristic features of the traffic classes. The impact of the QoS methods available on different service types were verified in the OPNET Modeler simulation environment. I examined mainly the potentials of the model to support the required quality parameters for the connections. The models of typical network applications, available in real UMTS networks, together with two examples of mobile networks, operating voice and video services in combination with standard data services, were defined in this simulation environment. My work also contains the detailed description of configuration parameters fundamental for correct behavior of the simulation models. The simulation also shows the case, when the transport service is rejected due to the lack of network resources. The key parameters of the model are also described and their effect on the service quality with and without QoS control are compared in separate scenarios. Finally, I investigated the effect of mobility of the end stations on the communication process, especially on the duration of a file transmission.
12

Generování datových jednotek v prostředí OPNET Modeler / Generation of data units in OPNET Modeler environment

Mikulica, Vladimír January 2010 (has links)
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.
13

Řízení pohybu stanice v simulačním prostředí OPNET Modeler podle mapového podkladu / Map-based Movement Control of Mobile Station in OPNET Modeler Simulation Environment

Jakúbek, Peter January 2011 (has links)
Diploma thesis focuses on a motion control of a mobile station in the simulation environment OPNET Modeler (OM). The thesis is summarized and described the possibilities of controlling the motion of a wireless mobile station. A significant part concentrates on the motion controlling of the station via an external file containing the path of movement. In this type of governance is a continuous movement of the station. The movement is driven by a simulation engine OM. External files designed for a motion control of the station can be created manually or used to write a data directly from OM to store the random generated routes for later use. For the manual creation of the trajectory is chosen the MATLAB tool that handles pre-created maps in the form of the input image into a form that the output of the tool can be used for motion control station in OM. To automate the process of creation and the subsequent trajectory motion control station is used by her library MATLAB Engine. It allows to call MATLAB functions from the language C/C ++ on which is based OM. For automated process of the movement control of the station is used a direct manipulation with the station position which is an alternative of the motion control station according to a set of the trajectory. The direct manipulation station position provides discrete movement of the station. The user’s created process which uses the discrete trajectory values manage the control.
14

Směrovací protokol OLSR pro MANET sítě v simulačním prostředí OPNET Modeler / OLSR routing protocol for MANET networks in OPNET Modeler simulation environment

Hošek, Petr January 2011 (has links)
The first part focuses on general routing of computer networks. It describes the importance of routing, basic elements, algorithms and protocols. It also describes the so-called MANET networks, where there are discussed routing protocols in these networks. The next chapter deals with the analysis of routing protocols OSPF version 3 and OLSR protocol. For both protocols basic algorithms, their use and structure are described. In OSPF protocol there is also described historical development and differences between versions 2 and 3. The OLSR protocol properly describes the principle of MPR nodes, which is one of the most important parts of the protocol which differs it from the others. Next there is a brief introduction of a powerful simulation tool OPNET Modeler which allows simulating the operation and behavior of almost any computer network with a very extensive possibility of options for the functioning of the entire network, as well as nodes it selves. The practical part is divided into five parts. The first section describes the structure of process models, the basic elements, variables, and block editors OSLR routing protocol in OPNET Modeler program. The second part is devoted to the ICI data structure, which is used for inter-process communication and verify the creation and reception of messages using this function. The third part deals with the process model of OLSR routing model. There is a description of various blocks and functions involved in its function of protocol and significance. The fourth chapter shows an extension of data unit protocol OLSR HELLO messages to other fields, which is able to transmit a numeric value between neighboring stations, and these values print it in the console. The last block of the practical part is dedicated to creating its own message which is broadcast between stations like part of the OLSR packet messages. This message includes the parameter of actual data traffic rate of each communicating stations. These values are for each station exported to an external file for later processing.
15

Ovládání generátoru sítového provozu z prostředí OPNET Modeler / Control of network operation generator from OPNET Modeler environment

Bartl, Milan January 2011 (has links)
In this work an interface between network simulator OPNET Modeler and network operations generator IxChariot is described. The goal is to control the generator by data from an OPNET modeler simulation. More accurately the generator is supposed to produce a data flow with desired settings of DSCP field, which is used to support quality of service mechanism. The goal can be achieved by two possible approaches: using IxChariot TCL API or IxChariot C API. Both of these approaches are described and conclusions are made at the end.
16

Zvýšení efektivity handoveru v reálném síťovém prostředí / Increasing the efficiency of the handover in real network environment

Michalec, Richard January 2011 (has links)
The aim of this work is to study methods of handover used in WiMAX and WLAN networks, next suggest the posibility of simulation methods for WLAN handover in the simulation environment OPNET Modeler. This work is focused primarily on obtaining the information about neighboring AP and subsequent selection of a new AP using such information. The work describes in detail each processes solutions that are used to implement newscanning methods
17

Pokročilé metody řízení trajektorie modelu stanice v prostředí OPNET Modeler / Advanced trajectory management techniques for model station in the OPNET Modeler environmen

Ludvíček, Pavel January 2011 (has links)
The aim of this work is to study and theoretically process existing movement options of station in OPNET Modeler environment. These options are described in first part. Furthermore to design and implement function to display path obtained from real-world conditions and done to station following this route during simulation. Coordinates used to move station are obtained by GPX format, which is used to store clearly the GPS coordinates. Second part is devoted to describing creation of this function, first using PHP script, then direct implementation into OPNET Modeler environment using C++.
18

Inovativní směrovací protokoly / Innovative Routing Protocols

Rouča, Tomáš January 2012 (has links)
The aim of this thesis was to get acquainted with the technology of routing data in a computer network. Thesis described in the theoretical level properties of current and past routing protocols and their use in information systems. Based on the acquired knowledge was created a simulation model of network communication in programming environment OPNET Modeler. This model analyzes the received parameters of the current protocols and their subsequent implementation in the real transmission technology using operating system Debian Linux. Finally, the transfer parameters are discussed between the simulation model and real transfer technology.
19

Výkonnost IP provozu / IP traffic performance

Bednář, František January 2012 (has links)
The master thesis „IP traffic performance“ is focused on traffic testing in IP networks. Theoretical section explains routing issue in an autonomous system. This work contains a detailed description of OSPF protocol. This work also deals with behavior of a link failure. There are described mechanisms that are used to link failure detection and subsequent traffic rerouting. The next section describes mechanisms to ensure quality of service. In master thesis are explained InterServ and DiffServ mechanisms. A large part is devoted to DiffServ mechanism that ensures distinction of data flows and classification packets into different classes. The routers than can process the individual data streams with different priorities. The practical section includes the design of experimental network and creation of simulation in Opnet Modeler. By using several scenarios are compared the characteristics of routing protocols and impact of QoS on the transmission characteristics of the network. Part of practical section is the improvement of OSPF protocol by adding a new metric and implementing a new metric in software suite Quagga.
20

Návrh a simulace optické přístupové sítě typu PON / Design and simulation of passive optical network PON

Mikauš, Jiří January 2012 (has links)
The aim of master's thesis was to demonstrate chosen PON network in simulation software OPNET Modeler. The work deals with passive optical networks. In particular, solutions that are based on the transmission of Ethernet frames. EPON and 10GEPON standards are described in theoretical section. EPON Standard was introduced already in 2004. Newer 10GEOPN is back compatible, which is ideal as a suitable solution for modern network with a high data rates demands. The practical part describes process of developing network nodes for passive optical network. EPON model was developed in simulation tool, that demonstrates basic features of the standard IEEE 802.3ah. The simulation results are demonstrated in last section.

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