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QoS assurance in wireless networks
Dvořák, Filip ; Vychodil, Petr (referee) ; Vymazal, Michal (advisor)
The bachelor´s work deals with wireless network WiFi and describes basic standards and their supplements. This work is divided into two parts - theoretical and practical. The first part of the work is applied to theoretic description of the best known standards IEEE 802.11 and detailed description of standard 802.11e. The second part of the work takes an interest in proposal and influence of service Wireless Multimedia in wireless network both in real world and in simulation program Opnet Modeler. Obtained results of the measurement are described and summarized in the conclusion.
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Implementation of Quality of Service into Wireless Networks
Kaman, Štěpán ; Růčka, Lukáš (referee) ; Škorpil, Vladislav (advisor)
Wireless networks are currently the frequent access connection to the local network or the Internet. Until 2005 there was no support in the 802.11 standard priority data and the use of multimedia services in these networks is problematic. Thesis deals with the standard IEEE 802.11 standard and quality of service support including IEEE 802.11e. They discussed methods of access to transmission medium, differences in the MAC sublayer, the reader issues in the transmission of priority data and the requirements for these data. In Opnet Modeler was created wireless network with access points and stations on which they are carried out simulations at different strain of transmitted data. It studied the difference in the use of DCF and EDCF method, used in the network with QoS support. In particular, it examined the behavior of priority voice and video data in both networks. The focus is on key parameters such as throughput, dropping data, packet loss, delay, jitter and the size of broadcasting front. The measured data are analyzed, and differences in the network without the support and promoting the quality of services are compared and evaluated. Part of this work is the role of laboratory in the Opnet Modeler.
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Quality of services in IP Telephony in Wirelass Networks
Slavíček, Tomáš ; Kyselák, Martin (referee) ; Vyoral, Josef (advisor)
The thesis deals with the principles of assurance quality of services in IP networks. The first part of the thesis describes specifications which are required by current applications for data network, and also illustrates the methods suitable for solving those requirements. The most attention is given to multimedia service VoIP whose development has not been finished from far. That theoretical knowledge implies in the second part of the thesis which analyzes the implementation of assurance QoS for the service VoIP within the standard 802.11, or more precisely, for wireless networks in general. The simulation of wireless networks within the program Opnet Modeler and the attest of the ability to assure QoS within both wireless networks and their limitations with an unswitched network are described in the next step. The current possibilities how to build up WLAN with the bearing QoS are sized up in conclusion.
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Modelling of advanced 802.11e technology features in OPNET Modeler environment
Šeliga, Michal ; Reichert, Pavel (referee) ; Molnár, Karol (advisor)
This master thesis includes a short review of the structure of WLAN (Wireless Local Area Network) technologies 802.11a/b/g, the description of their physical interface and the description of the basic medium access control mechanisms implementing the PCF (Point Coordination Function) and DCF (Distributed Coordination Function) methods. I mainly focused on the detailed evaluation the new 802.11e standard which was designed to efficiently support real-time services in wireless environment. To provide QoS (Quality of Service) support, this standard specifies the EDCA (Ehanced Distributed Channel Access) and HCF (Hybrid Coordination Function) medium access control methods for the shared wireless environment. The next chapter of my work is devoted to the verification of the theoretical results in OPNET Modeler simulation environment. I studied in details the WLAN model available in OPNET Modeler, the effect of data-flow classification into separate categories and the configuration of several access method parameters. Next, I created my own WLAN model according to the 802.11e standard. This model contains four applications two of them with real-time requirements. The model is divided into several scenarios, each focusing on different aspects of wireless network technologies like QoS support and it´s dependency on the number of clients, mobility of wireless terminals and comparison of the 802.11a/b/g and the 802.11e technology.
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Service quality support in WLAN networks
Mizera, Josef ; Hošek, Jiří (referee) ; Novotný, Vít (advisor)
The bachelor´s thesis is focused on wireless networks WiFi and the transmission of multimedia using these networks. It discusses the connection of telecommunication and data networks, their common use for transfer of data in real time, particularly through wireless transmission medium using standards IEEE 802.11. It describes individual standards 802.11, mainly 802.11e on which is this bachelor´s thesis focused. The second part of the work is focused on designing the networks for measuring to verify the functionality of service quality support in the tested networks.
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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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802.11n and 802.11e standards for wireless networks
Novák, Ondřej ; Morávek, Patrik (referee) ; Růčka, Lukáš (advisor)
This bachelor thesis is focused on broad issue of wireless network standards. It theoretically describes the most famous standards of IEEE 802.11 group, functions and behavior. It also closely analyzes the new standard 802.11n and the specification of 802.11e, WMM. The paper includes a report of practical tests of standards 802.11n and WMM, which serves for an objective appreciation of capabilities of these norms.
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VoIP and QoS
Kolmačka, Jan ; Křivánek, Vítězslav (referee) ; Kovář, Petr (advisor)
The bachelor’s thesis gives the basic information about the solution of a problem with Quality of Service in sequence with the VoIP telephony. In a few last years the VoIP technologies and basically the other multimedia applications have unbelievable grow. It is caused by a big demand internet user’s for the new interactive applications offering voice transfers and streaming video. These new habits bring quite big requests on networks from the side of QoS. That is why, it was necessary to develop new methods, which reach requested parameters of QoS in single categories. The first part discuss theoretically about protocols used in the VoIP telephony. The second part presents QoS, parameters of QoS and two basic methods for guarantee QoS. In the last part of the bachelor’s thesis is theoretically described the QoS support in Wi-Fi with the main aim on new technologies QoS reservation defined in the 802.11e. The following simulations and the results of the different settings parameters QoS are made by the powerful simulating software Opnet Modeler.
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Quality of Service Assurance introduction in Wireless Network
Branč, Martin ; Růčka, Lukáš (referee) ; Hošek, Jiří (advisor)
This bachelor´s thesis gives a complete overview of wireless networks 802.11.It describes the basic standards and their drafts. This thesis is divided into four chapters (sections), from which two are theoretical and two practical. The theoretical part contains a comprehensive overview of all standards, the history of wireless networks and technology. Further the support of quality of service in wireless networks is here analysed and in more detail standard 802.11e. In the practical part there is the network configuration described, at which the measurement was taken. The last part is already the implementation of support for quality of service, programme IxChariot measurement, evaluation of the results and differences between network traffic with and without support for quality of service.
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Quality of Services in Wireless Networks 802.11
Kopeček, Tomáš ; Skořepa, Michal (referee) ; Vyoral, Josef (advisor)
This bachelor’s thesis reports an integrated view of wireless networks of standard 802.11, known as Wi-Fi. It contains three main parts, the first two of them are theoretical knowledge. The first part of work have to do with the security issue of WLAN, the second part refers to security issue of quality of services (QoS). The aim of the third, practical part is to verify the right functions of standard 802.11e, which ensures the support of quality of services in networks 802.11. Because of huge expansion of multimedia services demand, is this support in wireless networks necessary.
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