The aim of this diploma thesis was to create an own DiffServ domain model, which is supplemented with stations generating various type of network traffic and implementation of token-bucket mechanism in router´s process model in Opnet Modeler simulation environment. DiffServ domain is made up from two edge and two core routers and includes servers and client stations generating VoIP, FTP, HTTP and database access traffic. It is described a process of distribution of traffic into different classes on edge routers of DiffServ domain along with assurance of separate handling with usage of an Assured Forwarding PHB mechanism. In point of differentiated packet processing is process model completed with generating of various statistics. The process of their creating is used to check a dropper activity, which is implemented together with token-bucket mechanism on ARP layer of the router. The functionality of the model is verified by simulation.

This thesis deals with the exploration of possibilities of LAN analysis with the use of the hardware analyzer Finisar TGHs from the Finisar Corporation Company. As a monitored network was choosed the local computer network in the laboratory PA-249 at the Department of Telecommunications, which is located at the Faculty of Electrical Engineering and Communication, Brno University of Technology. All results acquired from the complex long-term monitoring of the choosed LAN network are described in this thesis. Further, the thesis is focused on the simulation and analysis of the model of this network that was created in the simulation environment Opnet Modeler. The data obtained from the real LAN monitoring were used as a basis of an operating simulation of the transmission abilities and features of the real LAN network. The last part of the thesis describes the verification of the transmission capabilities and characteristics of the real LAN. Verification was performed in Opnet Modeler, where the network has been analyzed in detail.

Information about the differentiated services (DiffServ), the link failure problems and the alternate routes in a DiffServ domain finding are the aims of the master´s thesis to be given. Properties of the differentiated services, the usage of marking techniques in the DiffServ domain are described in the thesis. The concept of the DiffServ domain, its structure and mostly used today routing protocol OSPF are described too. The function model of the DiffServ domain has been created in the simulation environment called Opnet Modeleler on the basis of the obtained knowledge. The link failure and the following link recovery have been simulated in the model and the effects have been analyzed after that.

Diploma thesis deals with assign and distribution quality of service in mobile UMTS telecommunication networks. The project consists of two parts, theoretical and practical. Theoretical part of the project is focused to familiarize with functionality of the UMTS network with the main aspect at admission mechanism in radio part of the network as well as quality of service assign mechanisms according to service demands within core network of UMTS. Practical part of the project is given to simulation program OPNET Modeler and its capabilities in network design and testing various parameters of UMTS network with implementation quality of service mechanism. As the asset of diploma thesis becomes designed functional prototype of UMTS network with various options for individual settings user equipment as well as fixed mobile networks nodes.

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.

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.

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.

The thesis deals with MANET networks and it focuses on the routing process. Most attention is paid to the routing protocols AODV and OLSR. These protocols are described in the detail. The aim of the thesis is to create a simulation model of MANET network in OPNET Modeler environment. In this model the AODV protocol is configured. In order to achieve improved characteristics of the network traffic the routing protocol parameters are optimized. Furthermore the process model of AODV protocol in this environment is studied and extended by a new type of message, which allows a transfer of current transmission speed of MANET station network interface. Current transmission rate of stations is retrieved from the statistics. Every station periodically sends a message to neighboring nodes. The node stores the information into the file when a new message arrives.

This diploma thesis deals with modeling wireless transmission in simulation environment OPNET Modeler. In theoretical part, there is described the very substance of spreading the signal via electromagnetic wave including impact of the surroundings that affects the spreading. These impacts have an influence on described selected parameters of wireless transmission of the signal characterizing its quality. Furthermore, there is described the OPNET Modeler setting, which allows designing the wireless transmission and by means of simulation verifies its functionality and acquires it is parameters. The transmission of the signal from transmitter to receiver itself is divided to individual steps, which are described in detail considering the implementation in aforementioned environment. In practical part, there is configured the basic model of wireless network and also executed series of simulations with different variants of commonly adjustable basic parameters of the transmission, as signal modulation, antenna types and network topology. Additionally, attention is turned to the stages of transmission itself, philosophy of their cooperation based on sharing the information via data units called TDA and their implementation in source code of the C++ language called transmission models. Based on these foundations is beyond beforehand defined created new user TDA and by means of simulation verified its correct implementation within packet switching. Values of the selected including user TDA are written in the window of simulation console with the help of the C++ language. Acquired results of the simulations are analyzed and documented in the conclusion. Source codes are available in the diploma thesis appendix.

The theoretical part of Master's thesis has been dealing with issues of MANET networks, issues of providing quality of services in MANET networks and analysis of various implementations of quality of services in these networks. At the start of the practical part of this thesis was described modified OLSR process model with support of quality of services. In simulation program OPNET Modeler was designed a topology of MANET network, firstly was run a simulation of this network without any support of quality of services and then was run a simulation with support of quality of services. The results of these simulations were analyzed, compared and graphically interpreted. In the next part of this thesis was designed a real MANET network with OLSR support. OLSR network communication was captured with the use of Wireshark. In the last part of this thesis was firstly described a meaning and functions of plugins in OLSR implementation and then was developed a plugin which is responsible for sending messages which contain a state of the links between nodes of MANET networks.