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.

This thesis called Simulation scenarios in an IT Guru enviroment for Communication Technologies deals with the design of laboratory experiments for the above-mentioned subject. The first part is a theoretical introduction to the protocols. The practical part contains the tasks itself. The work includes four laboratory tasks with a detailed description of the work and an illustrative pictures. The first two tasks are focused on the application protocols, with which the user comes into contact with every day. The other two are focused on routing protocols, precisely the internal routing protocol IS-IS and BGP external routing protocol. A free version of simulation software OPNET Modeler and IT Guru enviroment version 9.1.A were used to create the work.

The main topic of this master´s thesis is a practical simulation of wireless mobile networks. For this purpose, the model simulating urban enviroment in which mobile nodes move according to desgined trajectories was created. The parameters of transmitted signal and impact of obstacles in the way of propagation were examined by the simulation. Number of obstacles and type of material of given obstacle was taken into consideration.

This thesis consists of theoretical and practical parts. The theoretical part contains an analysis of the problems of wireless networkssolutions individual standards and methodologies to ensure quality of service. In the practical part using the OPNET Modeler, a number of different simulation models and their evaluation. It is a model of individual standards, support mobility and interference effects on quality of service.

The doctoral thesis is focused on a research in the area of the quality-of-service support technologies in data networks. The current modern communication networks cannot operate correctly without an effective tool allowing differentiated treatment for various network traffic classes. Looking at the current trends in this area it turns out that the technology of Differentiated services is currently the most widely used mechanism for QoS assurance in data networks. The major part of this doctoral thesis concerns the design of a novel QoS system which offers a solution for one of the main problems of DiffServ technology. This disadvantage lies in the missing cooperation between the end station and edge node of the DiffServ domain. To overcome this limitation the system proposed introduces an improvement which enables the user application to actively participate in the resource reservation process by direct configuration of the DSCP value in the IP header of its own packets. This functionality is based on the identification of DiffServ configuration parameters available in the edge router. To retrieve the information required from network component the well-known SNMP protocol has been chosen, which has direct access to the components’s configuration stored in the MIB database. On the basis of this theoretical proposal several simulation scenarios have been created and analysed. The results show that the system designed presents an efficient solution for the mentioned problem of DiffServ. They also give good assumptions for the successful implementation of this system into a real environment.

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Approved for public release; distribution in unlimited. / As the popularity of Internet soars, the content on the Internet is increasingly accessed by mobile devices that are usually small in form factor and limited in resources, in terms of processing capability, bandwidth and battery power. With the changing environment, content providers must serve a large number of access devices with different profiles, while the users have access to a large number of services with different content types. A key challenge in such an environment is how to enable the best possible fit between content and capabilities of a specific access device type. The goal of this thesis research is to explore on the concept of a device-aware network (DAN) that can provide the infrastructure support for device-content compatibility matching to avoid the unnecessary wastage of network and device resources that happens in current device-ignorant networks. A more efficient architecture is proposed which encapsulates device profile information in transmitting packets and incorporates content repurposing functionality in existing network entities, such as routers along the data path. Simulation models are developed to statistically evaluate the performance of the proposed architecture in comparison to existing content repurposing frameworks. The results demonstrated the feasibility and suitability of the architecture, with improvement in network bandwidth conservation. / Civilian, Singapore Defence Science and Technology Agency

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.

This thesis discusses wireless network standards 802.11a/b/g/n. First part explains basic principles of networks and media access. Next the standard IEEE 802.11, general QoS parameters and their application in wireless networks, according to standard 802.11e are analyzed. Second part of the thesis verifies the acquired knowledge in simulating program Opnet - effects of the delay, jitter and packet loss on VoIP call are tested. In the last part of the thesis a network for video streaming has been designed. The video was streamed in different qualities and the influence of other network traffic (with and without the support of QoS) on the video streaming was tested.

ZigBee is a substandard of IEEE 802.15 family that is specially designed to take care of factors such as power, data rate and area that primarily affect network performance. This has controlling and monitoring capability, which finds potential applications in different sectors. ZigBee allows the concept of hybrid networks and mobility. A comprehensive analysis of ZigBee networks was carried out by constructing and simulating the networks to evaluate the performance in terms of throughput, delay, network load, and packets dropped. This research is aimed at evaluating the effect of network topology on the system performance. A careful review of simulation platforms brought the conclusion of using OPNET Modeler which has the required frame work. Different network topologies of simple and hybrid were built and simulated. Throughout the simulations, the best-case scenarios were drawn to the conclusion by the graphical analysis of parameters of evaluation. Mobile networks were constructed and simulated to investigate the effect of mobility on communication.