This work deals with performance and security testing of blockchain protocols based on the Proof-of-Stake (PoS) consensus model. It describes properties, problems, but also the use of blockchain systems. On theoretical levels, this thesis compares the properties and resistance to various attacks of numerous PoS protocols, specifically Algorand, Casper, Gasper, Snow White, Stellar and Decred. Additionally, this work implements a protocol simulator of Algorand, Casper FFG and Gasper. The simulator is built on top of the Bitcoin Simulator simulation tool, which is based on the NS-3 discrete network event simulator. Then, it compares the properties of the implemented protocols using discrete simulation.

Purpose of this master thesis was to explain simulation of real network, point to the imperfection during these simulations and try to find out technologies and solutions that could improve credibility of simulation. For this purpose, network simulator ns-3 has been chosen which supports direct code execution together with Quagga software suite. Master thesis describes internet protocol IPv4, UDP protocol, basics of routing and detailed explanation of OSPF routing protocol. Focus in this thesis is also on general description of simulation, its kinds and detail explanation of discrete simulation that is used by ns-3 simulator. Next chapter explains theory of ns-3 simulator, its development, conceptual overview and objects. Direct code execution and Quagga that both help improve credibility of simulation, are described in last chapter of theoretical part of thesis. In practical part of thesis is explained how to install and configure all three implemantaions of ns-3 simulator on Ubuntu, linux distribution. On the basis of obtained knowledge, the simulation model has been designed, also there has been given detailed explanation of how to create new model of simulation and how to analyze its results for all implementation.

This diploma thesis deals with the implementation of standard IEEE 802.11ah into network simulator NS-3. The first part of the diploma thesis describes M2M communication for which the standard IEEE 802.11ah would be suitable. M2M communication is being more and more used in the society, that is why there is an effort to develop a new standard for this type of communication. The thesis contains a description of this standard based on technical specifications brought out by the Task Group ah (TGah). Some changes have been made in NS-3 for the purpose of this thesis in order to support this standard. In the next part there is a created scenario with basic topology in NS-3 with usage of standard IEEE 802.11ah, in which the functionality of the standard is tested. The result of this diploma thesis is a description of the changes which have been made and analysis of the output files from the simulation.

The objective of this research is to investigate improved methods for distributing certificate revocation lists (CRLs) in vehicular ad hoc networks (VANETs). VANETs are a subset of mobile ad hoc networks composed of network-equipped vehicles and infrastructure points, which will allow vehicles to communicate with other vehicles and with roadside infrastructure points. While sharing some of the same limitations of mobile ad hoc networks, such as lack of infrastructure and limited communications range, VANETs have several dissimilarities that make them a much different research area. The main differences include the size of the network, the speed of the vehicles, and the network security concerns. Confidentiality, authenticity, integrity, and availability are some of the standard goals of network security. While confidentiality and authenticity at times seem in opposition to each other, VANET researchers have developed many methods for enhancing confidentiality while at the same time providing authenticity. The method agreed upon for confidentiality and authenticity by most researchers and the IEEE 1609 working group is a public key infrastructure (PKI) system. An important part of any PKI system is the revocation of certificates. The revocation process, as well as the distribution of revocation information, is an open research problem for VANETs. This research develops new methods of CRL distribution and compares them to existing methods proposed by other researchers. The new methods show improved performance in various vehicle traffic densities.

Diploma thesis deals with the implementation of LTE Cat-M1 technology in simulator NS--3 (Network Simulator 3). The theoretical part of the thesis summarizes key terms concerning IoT (Internet of Things), M2M (Machine-to-Machine) communication, LTE (Long Term Evolution) and LPWA (Low-Power Wide Area) networks. The practical part summarizes the possibilities of currently available modules for cellular technologies for NS-3, ie. the LENA module and the subsequent extension of LENA+ and ELENA. Simulation scenarios offer a comparison of LTE/LTE-A and LTE Cat-M1 (also known as eMTC - enhanced Machine Type Communication) technologies for M2M communication. The results of the simulations are well-arranged in the form of graphs and discussed at the end of the thesis.

Předkládaná disertační práce je zaměřena na \uv{Modelování propagačního kanálu pro off-body komunikaci v oblasti milimetrových vln}. Navzdory pokrokům v rámci bezdrátových sítí v přímé blízkosti člověka stále systémy 5. generace postrádají dostatečnou šířku pásma a dostatečně nízkou odezvu. To je způsobeno neefektivním využíváním rádiového spektra. Tento nedostatek je potřeba co nejdříve odstranit a právě z tohoto důvodu je hlavním cílem této práce navrhnout vylepšený model rádiového kanálů pro off-body komunikaci. Úkolem tohoto modelu je umožnit uživatelům efektivněji a přesněji simulovat propagaci signálu v rámci daného prostředí. Navržený model je dále optimalizován a ověřen vůči nejnovějším měřením, získaným z literatury. Nakonec je tento model implementován do simulačního nástroje NS-3, pomocí kterého je následně využit k simulaci množství scénářů. Hlavním výstupem této práce je ověřený model přenosového kanálu pro off-body komunikaci v rámci milimetrových vln, společně s jeho implementací do simulačního nástroje NS-3, díky čemuž je dostupný pro širokou veřejnost.

This work is focused on the issue of wireless networks according to the IEEE 802.11 standard. The main subject of research is the Rate Adaptation Algorithms (RAA). The work also contains a description of simulation environments NS-3 and OMNeT in terms of adaptation algorithms. At the end of the work there is a summary of wireless network simulations in NS-3 and OMNeT environments and their comparison with the actual measurement of network parameters.

Diploma thesis provides an introduction to the ns-3 network simulator. It describes the basic abstactions and components of the instrument. This work further discusses the theory, which was applied during simulation creation. The concept of unicast, the issue of IP addressing and routing in networks are specificaly analyzed. The practical part is focused on the creation of four laboratory tasks within the scope of Advanced Communication Techniques. The first task is dedicated to the the issue of static unicast routing in the network. It clarifies the impact of metrics on the process of routing. The following task compares the different types of ICMPv4 and ICMPv6 messages. The third task discusses additional functions of the ICMPv6. Specifically, it focuses on five different types of ICMPv6 messages defined by NDP (Neighbor Discovery Protocol) and their role in the network traffic. The last task focuses on ensuring the quality of services (QoS) in wireless networks, by setting priorities and thereby dividing the traffic into different classes. Attention is focused on parameters such as throughput, delay and jitter.

This thesis is focused on the smart public lighting management possibilities. It describes smart public lighting management itself and the advantages of the new management possibilities compared to the current ones are illustrated as well. Furthermore, it deals with a comparison of the most used light resources and LED light resources. This thesis also outlines NS-3 simulation environment and states its advantages. Theoretical concept for energy-saving smart public lighting management system and its modifications for the needs of simulation is described in the paper. This theoretical concept is simulated and compared with the current smart public lighting management systems as well as with the systems designated by the third party.

The diploma thesis „Analysis and prediction of data traffic in mobile Ad Hoc network“ focuses on the radio propagation models of services in MANET (Mobile Ad-hoc) networks. It describes MANET networks and covers the theoretical analysis of routing protocols, radio wave propagation and propagation models of simulation enviroment NS-3 (Network Simulator 3). Furthermore, there is processed the creation process of model MANET networks with the routing protocol AODV (Ad Hoc On Demand Distance Vector) in the simulation environment NS-3. For analysis purposes there were implemented new functions to capture value of SNR (Signal to Noise Ratio) and throughtput. For this reason a physical layer of one of NS-3 model was modified. As an result there is a simulation build that compared several number of propagaion models.