The subject of this diploma's thesis is to create a design of a fiber optic network, which will allow an access to broadband internet connection for households living in blocks of flats in Kojetín. For this purpose the best technologies will be compared by analysis and the new network topology will be designed. The investor is a civic association Cyrilek.net that provides a wireless internet at this area. The best solution will be selected on the basis of financial and technical analysis and the investment will be calculated including its return. This innovation not only give people a really fast internet connection, but also the possibility of other services such as IPTV or VoIP.

This thesis deals with the design and theoretical description of the hybrid control system for quadrocopter. First, a mathematical model is presented, sensors needed for development and their principles. This work shows the system architecture design and scheme of communication channels between the blocks. Implementation section discusses specific uses of computing nodes/sensors and their settings. In this thesis there are illustrated messages sent between computing nodes and the control loop machine. It also describes how to test the sensors, measurement results and techniques for improvement.

This master's thesis deals with the idea of using mobile devices as sensor nodes in wireless sensor network. Focused mostly on Android platform, we explore possibilities of wireless communication, and describe various types of sensors on mobile devices. We design and implement wireless sensor network based on mobile devices running Android operating system. The network performs real-time capturing of data from all sensors available and optionally from GPS. All measurements are visualized at the base station, which is Java Standard Edition desktop application. Wi-Fi, Bluetooth or even cellular internet can be used for communication within the network. Nodes can be remotely configured via SMS messages.

This work deals with the study of Yagi-Uda antennas, followed by analysis and design of planar antenna with wired reflector. The first part focused on the analysis of the antenna and parameters. Another part of the continuing investigation of the optimum parameters for a given antenna followed by a design in Wi-Fi 5 GHz band. The antenna is simulated in CST Microwave Studio. The final part devoted the results achieved

Over the past three decades, agricultural machinery has made the transition from purely mechanical systems to hybrid machines, reliant on both mechanical and electronic systems. A this transformation continues, the most modern agricultural machinery uses networked systems that require a network connection to function to their full potential. In rural areas, providing this network connection has proven difficult. Obstacles, distance from access points, and incomplete coverage of cellular connection are all challenges to be overcome. “Off the shelf” commercial-grade Wi-Fi equipment, including many products from Ubiquiti like the Bullet M2 transceiver and the PowerBeam point-to-point linking system, as well as antennas by Terrawave, Crane, and Hawking, were installed in a purpose-built system which could be implemented on a production farm. This system consisted of a tower-mounted access point which used an antenna with a 65^o beamwidth, and the test included distances up to 1150 meters in an agricultural setting with corn and soybeans. Some sensors were stationary and the other platform was a tractor following a path around the farm with both 8dBi and 15dBi gain antennas. Through all tests, throughput never dropped below 5 Mb/s, and the latency of successful connections never exceeded 20ms. Packets were rarely dropped and never accounted for a significant portion of all packet transmission attempts. Environmental effects like immediate precipitation, crop heights, recent rainfall, and ambient temperature had little or no effect on wireless network characteristics. As a result, it was proven that as long as line-of-sight was maintained, reliable wireless connectivity could be achieved despite varying conditions using microwave radiation. Network throughput was marginally affected by the change in free space path loss due to increased distance between the access point and the client, as well as travel by the mobile client outside the beamwidth of the access point. By enabling this coverage, it is hoped that the implementation of new agricultural technology utilizing a live network connection will progress more rapidly.

Small cells are deployed in a crowded areas with a high demand for both coverage and capacity. It is hard to address both of these requirements simultaneous with a conventional mobile network architecture based on macro cells. In many case a wire is not available to connect the small cell to the core of the mobile network. Under these circumstances a wireless link could be a convenient solution for the backhaul. In this master’s thesis IEEE 802.11n technology was evaluated to assess its suitability for backhaul from a small wireless cell. The performance of wireless equipment manufactured by several vendors has been measured. The results of these measurements were analyzed and compared to a set of requirements established for small cell backhaul. The analysis has affirmed that IEEE 802.11n is capable of providing sufficient performance to be used for small cell backhaul in various deployment scenarios. Note that in this thesis we include femtocells, picocells, wireless LAN access points, and other technologies in the category of "small cells". Another research questions of this master’s thesis is security of small cell backhaul. In addition to protecting the backhaul link itself, the security research investigated the safety of the whole mobile network architecture remodeled with the introduction of small cells. A mechanism to integrate secure small cells into a mobile network was developed. The results obtained during the project will be used as an input for product development activities in the company hosting the project. The resulting product could become the target of future wireless system performance measurements. / Små celler sätts ut i områden med höga krav på täckning och kapacitet. Det är svårt att adressera båda dessa krav samtidigt med en konventionell mobil nätverksarkitektur baserad på makro-celler. I många fall finns ingen kabel tillgänglig att koppla den lilla cellen till kärnan i det mobila nätverket. Under dessa omständigheter kan en trådlös länk vara en lämplig lösning för backhaul. I denna avhandling utvärderas IEEE 802.11n-teknikens lämplighet för backhaul av små celler. Prestandan hos trådlös utrustning tillverkad av flera olika tillverkare har mätts. Resultaten av dessa mätningar analyserades och jämfördes med en mängd krav uppsatta för backhaul av små celler. Analysen har förankrat att IEEE 802.11n är kapabel till att tillhandahålla tillräcklig prestanda för backhaul av små celler i diverse miljöer. Notera att i denna avhandling så inkluderas femto-celler, pico-celler, Wireless LAN-åtkomstpunkter, och andra teknologier i kategorin små celler". Andra forskningsfrågor berörda i avhandlingen är säkerhet vid backhaul av små celler. Utöver att skydda backhaul-länken själv så undersökte säkerhetsforskningen säkerheten av hela mobilnätsarkitekturen när små celler används i arkitekturen. En mekanism för att integrera säkra små celler i ett mobilnät utvecklades. De resultat som införskaffades under projektets genomförande kommer att användas som input till produktutvecklingsaktiviteter hos företaget som sponsrade projektet. Den resulterande produkten skulle kunna bli mål för framtida prestandamätningar av trådlösa system.

Tools that automate processes are always sough after across the entire IT field. This project's aim was to build and evaluate a semi-automated reconnaissance tool based on a Raspberry Pi 4, for use in penetration testing and/or digital forensics. The software is written in Python 3 and utilizes Scapy, PyQt5 and the Aircrack-ng suite along with other pre-existing tools. The device is targeted against wireless networks and its main purpose is to capture what is known as the WPA handshake and thereby crack Wi-Fi passwords. Upon achieving this, the program shall then connect to the cracked network, start packet sniffing and perform a host discovery and scan for open ports. The final product underwent three tests and passed them all, except the step involving port scanning - most likely due to hardware and/or operating system faults, since other devices are able to perform these operations. The main functionalities of this device and software are to: identify and assess nearby network access points, perform deauthentication attacks, capture network traffic (including WPA handshakes), crack Wi-Fi passwords, connect to cracked networks and finally to perform host discovery and port scanning. All of these steps shall be executed automatically after selecting the target networks and pressing the start button. Based on the test results it can be stated that this device is well suited for practical use within cyber security and digital forensics. However, due to the Raspberry Pi's limited computing power users may be advised to outsource the cracking process to a more powerful machine, for the purpose of productivity and time efficiency.

Long time ago, there were developed methods which can allow fast exchange of information at the longest distance possible. Until recent time, the possibilities of long way communications were very limited. There were technological and financial limitations mainly. With telegraph, telephone and the newest – computer networks invention, the telecommunication services became cheaper and much more comprehensive. With accession and high scale spread of internet, the role of communications is much more important. The most actual trend is mobile internet and connected multimedia networks and their instant accessibility from anywhere. On the first side there are classical telecommunication networks as GSM, UMTS, on the other side there is very strong alternative in shape of WiMAX and WiFi networks combination. For the usage of multimedia services in that networks is very important to handle their prefferization over other traffic, which is very difficult task even on wireless media. For the finding of new processes and methods, which can allow it, there is, at fist, the need for highly accurate and authentic mathematical models. In this doctoral thesis is mapped actual state of the art and proposed the new mathematical model of Distribution Coordination Function, which is much-frequent used as access method in 802.11 networks, Wi-Fi.

The usage of public Wi-Fi and hotspots has witnessed a substantial increase in recent times, providing convenient connectivity in various public areas. Public wireless networks are now widely accessible, especially in smart cities. However, utilising public Wi-Fi exposes individuals to potential threats to their privacy and security. Hackers can exploit vulnerabilities present in public Wi-Fi networks, such as the "Evil Twin" attack, to deceive users and unlawfully obtain their personal information. The main objective of the research was to investigate people's awareness of the security risks associated with public Wi-Fi usage and to identify the factors that contribute to their willingness to take such risks. The research adopted a qualitative approach, utilising semi-structured interviews with 14 participants to gain valuable insights into their understanding and knowledge of the risks connected with public Wi-Fi. The majority of respondents employed public Wi-Fi for educational purposes, browsing the Internet, and engaging with social media platforms. Additionally, the findings of the study explored the motivations and influences that lead individuals to take risks when using public Wi-Fi. Factors such as convenience, cost-effectiveness, saving mobile data usage, limited mobile network coverage, and a lack of awareness concerning privacy and security risks emerged as the most significant reasons and influences behind the utilisation of public Wi-Fi.

Traditional methods for locating books and resources in libraries often entail browsing catalogsor manual searching that are time-consuming and inefficient. This thesis investigates thepotential of automated digital services to streamline this process, by utilizing Wi-Fi signal datafor precise indoor localization. Central to this study is the development of a model that employsWi-Fi signal strength (RSSI) and round-trip time (RTT) to estimate the locations of library userswith arm-length accuracy. This thesis aims to enhance the accuracy of location estimation byexploring the complex, nonlinear relationship between Received Signal Strength Indicator(RSSI) and Round-Trip Time (RTT) within signal fingerprints. The model was developed usingan artificial neural network (ANN) to capture the relationship between RSSI and RTT. Besides,this thesis introduces and evaluates the performance of a novel variant of the Particle SwarmOptimization (PSO) algorithm, named Randomized Particle Swarm Optimization (RPSO). Byincorporating randomness into the conventional PSO framework, the RPSO algorithm aims toaddress the limitations of the standard PSO, potentially offering more accurate and reliablelocation estimations. The PSO algorithms, including RPSO, were integrated into the trainingprocess of ANN to optimize the network’s weights and biases through direct optimization, aswell as to enhance the hyperparameters of the ANN’s built-in optimizer. The findings suggestthat optimizing the hyperparameters yields better results than direct optimization of weights andbiases. However, RPSO did not significantly enhance the performance compared to thestandard PSO in this context, indicating the need for further investigation into its application andpotential benefits in complex optimization scenarios.