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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
381

Resource allocation in cellular Machine-to-Machine networks

Alhussien, Nedaa 06 December 2021 (has links)
With the emergence of the Internet-of-Things (IoT), communication networks have evolved toward autonomous networks of intelligent devices capable of communicating without direct human intervention. This is known as Machine-to-Machine (M2M) communications. Cellular networks are considered one of the main technologies to support the deployment of M2M communications as they provide extended wireless connectivity and reliable communication links. However, the characteristics and Quality-of-Service (QoS) requirements of M2M communications are distinct from those of conventional cellular communications, also known as Human-to-Human (H2H) communications, that cellular networks were originally designed for. Thus, enabling M2M communications poses many challenges in terms of interference, congestion, spectrum scarcity and energy efficiency. The primary focus is on the problem of resource allocation that has been the interest of extensive research effort due to the fact that both M2M and H2H communications coexist in the cellular network. This requires that radio resources be allocated such that the QoS requirements of both groups are satisfied. In this work, we propose three models to address this problem. In the first model, a two-phase resource allocation algorithm for H2H/M2M coexistence in cellular networks is proposed. The goal is to meet the QoS requirements of H2H traffic and delay-sensitive M2M traffic while ensuring fairness for the delay-tolerant M2M traffic. Simulation results are presented which show that the proposed algorithm is able to balance the demands of M2M and H2H traffic, meet their diverse QoS requirements, and ensure fairness for delay-tolerant M2M traffic. With the growing number of Machine-Type Communication Devices (MTCDs) the problem of spectrum scarcity arises. Hence, Cognitive Radio (CR) is the focus of the second model where clustered Cognitive M2M (CM2M) communications underlaying cellular networks is proposed. In this model, MTCDs are grouped in clusters based on their spatial location and communicate with the Base Station (BS) via Machine-Type Communication Gateways (MTCGs). An underlay CR scheme is implemented where the MTCDs within a cluster share the spectrum of the neighbouring Cellular User Equipment (CUE). A joint resource-power allocation problem is formulated to maximize the sum-rate of the CUE and clustered MTCDs while adhering to MTCD minimum data rate requirements, MTCD transmit power limits, and CUE interference constraints. Simulation results are presented which show that the proposed scheme significantly improves the sum-rate of the network compared to other schemes while satisfying the constraints. Due to the limited battery capacity of MTCDs and diverse QoS requirements of both MTCDs and CUE, Energy Efficiency (EE) is critical to prolonging network lifetime to ensure uninterrupted and reliable data transmission. The third model investigates the power allocation problem for energy-efficient CM2M communications underlaying cellular networks. Underlay CR is employed to manage the coexistence of MTCDs and CUE and exploit spatial spectrum opportunities. Two power allocation problems are proposed where the first targets MTCD power consumption minimization while the second considers MTCD EE maximization subject to MTCD transmit power constraints, MTCD minimum data rate requirements, and CUE interference limits. Simulation results are presented which indicate that the proposed algorithms provide MTCD power allocation with lower power consumption and higher EE than the (Equal Power Allocation) EPA scheme while satisfying the constraints. / Graduate
382

Transversality of Information and Communication Technologies in the Prevention of Gender-Based Violence from a Multilevel Approach — Proposals of Application / Transversalidad de las Tecnologías de la Información y las Comunicaciones en la Prevención de la Violencia de Género desde un Enfoque Multinivel — Propuestas de Aplicación

Rodríguez Rodríguez, Ignacio 24 March 2021 (has links)
En la presente tesis se estudia, bajo la forma de compendio de publicaciones, el rol que pueden jugar las denominadas Tecnologías de la Información y la Comunicación (TIC) en la raíz de la desigualdad de género y las violencias que se desencadenan a partir de ésta. Muchas investigaciones se han centrado en la Violencia de Género (VG) y su conexión con otros temas relacionados, así como sus causas, orígenes, y medidas para hacerle frente. La interseccionalidad de las cuestiones de género, y dentro de éstas, la violencia, obliga a que el enfoque sea transversal y se aborde en diversos ámbitos (multinivel). A pesar de este enfoque múltiple y teniendo en cuenta que la forma en que se desarrolla la violencia y su impacto en las mujeres en un entorno caracterizado por el uso de las TIC, (teléfonos móviles, redes sociales o, en general, el uso de Internet), no se ha estudiado ni documentado suficientemente aún esta vertiente tecnológica. Esta tesis aborda las intersecciones entre las TICs y el ámbito de la igualdad y la VG como si de un relato cronológico se tratara. Así, primeramente, se parte del estudio del ámbito docente como origen de las brechas de género educativa y digital, las cuales, a la postre, pueden representar el germen de la desigualdad y la violencia. En este ámbito educativo, se analizan las distintas medidas que las universidades implementan basándose en aspectos tecnológicos para mitigar la violencia que se puede producir en dicho entorno. Con posterioridad, se evalúa la posible predicción de las agresiones mediante técnicas de aprendizaje máquina. Seguidamente, se analiza la gestión de esta violencia de género en un entorno Internet of Things y, finalmente, se aborda la protección de las personas supervivientes de VG por el uso de biosensores y análisis inteligente de datos.
383

Regulátor solárního ohřevu bazénu / Solar pool heater

Jablončík, Lukáš January 2017 (has links)
The master´s thesis deals with the design of the solar heating regulator of the swimming pool. The basis was to study the available solutions for the solar pool controllers, to define the requirements, to design the concept and the block diagram of the own thermostat. The thesis also provides a description of several for the Internet of Things. The most suitable is used to control the thermostat. The resulting thermostat regulates two power outputs for filtration and the pump, it can be set using the keyboard and graphic display. At the end of the work is practically verified functionality on the model and on the real pool with solar heating.
384

Bezpečná autentizace a klíčový management v Internetu věcí / Secure Authentication and Key Management in the Internet of Things

Škunda, Patrik January 2018 (has links)
This thesis deals with issues of secure authentication and key management in the Internet of Things. It describes basic protocols used in IoT, cryptographic primitives, communication technologies in IoT and end elements. It also includes a measuring the performance of cryptographic primitives on Raspberry Pi and selecting the appropriate LPWAN simulation technology. The conclusion of the work is devoted to the simulation of a LoRaWAN network
385

Auto počítač založený na Raspberry Pi / Car computer based on Raspberry Pi

Matula, Vladimír January 2020 (has links)
The main goal of this diploma thesis is to investigate the smart cars field together with the technologies linked closely to it. Further, the thesis offers an overview of options to extend the vehicle capabilities with the car computer created with the Raspberry Pi Zero W. The thesis provides hands-on experience and is stuctured into two parts. The first, theoretical section focuses on Internet of Things and Machine to Machine communication. It also describes the currently available smart car solutions on the market, their pros and cons. The practical part of this thesis describes design and creation of a smart computer based on Raspberry Pi Zero W with draft of self-made security system from vehicle containing a motion sensor and a camera. It also includes a development and integration steps with a mobile application capable of viewing the static information regarding the car state, such as Rotations per minute. Vehicle speed, etc. The created system also has the capability of informing the user about it's current location on request.
386

Implementace a vyhodnocení komunikační technologie LoRaWAN v simulačním prostředí NS-3 / Implementation of the LoRaWAN Communication Technology Using the Network Simulator 3

Mašek, Petr January 2021 (has links)
The diploma thesis focuses on the description of LPWAN (Low Power Wide Area Network) technologies for use in IoT (Internet of Things) communication scenarios. The theoretical part compares communication technologies operating in the license-exempt frequency band, i.e. Sigfox and LoRaWAN (Long Range Wide Area Network). Furthermore, technologies using the licensed frequency spectrum are discussed, specifically, attention is focused on NB-IoT (Narrow Band IoT). Emphasis is placed on LoRaWAN technology and the properties of the unlicensed frequency band below the 1 GHz, which is utilized by this technology. The practical part of the thesis consists of the evaluation of simulation scenarios using an integrated module in the simulation environment NS-3 (Network Simulator 3). Attention is focused mainly on the analysis of data transmission success using selected communication parameters of LoRaWAN technology. The obtained simulation outputs with a focus on mMTC (massive Machine-Type Communication) communication scenarios confirm the relationship between the number of end devices and gateways, communication distance and transmission reliability, or the limit value for the duty cycle.
387

Systém zabezpečení včelích úlů před nepovolenou manipulací / Beehive security system against unauthorized manipulation

Milota, Martin January 2021 (has links)
This master thesis deals with the design of beehive security system against unauthorized manipulation. The system uses LoRaWAN wireless communication technology for data transmission. The device records the movement of the beehive using an accelerometer and then locates the beehive using a GPS module. The low-energy system works via a battery-powered ESP32 microcontroller and is located on a beehive. The battery is charged using a solar panel. The system can be modularly expanded with additional sensors to monitor the condition of the bees. The device has been tested in practice, where it has been confirmed that it meets the required properties for securing beehives.
388

Living With Things : An open-source approach to the exploration of IoT through speculative design and hacking

Alushi, Nefeli January 2021 (has links)
In the field of human-computer interaction, the majority of domestic IoT and smart devices run on proprietary software that possess limited technical properties and predetermined functionalities. As practices of building, modifying, and making IoT applications grow, this thesis follows an open-source approach to IoT to investigate the relationships of humans and things in a domestic setting. As a result of this material exploration, proprietary frameworks for interactions with smart devices are challenged through speculative scenarios, that include diverse instances of human-things interactions. Thus, a research through design methodology is suggested to support series of experiments, conducted to explore instances of perceived intelligence of these open-source hardware, without the use of advanced computational systems as proprietary devices entail. The suggested process is the creation of a speculative design artifact that combines hacking practices, to support designers in generating insights and to further iterate on possible open-source IoT interactions.
389

LORA PERFORMANCE AND ITS PHY LAYER PARAMETERS IN 915MHZ ISM BAND IN INDOOR ENVIRONMENTS

Shinhye Yun (11559760) 22 November 2021 (has links)
<p>How LoRa/LoRaWAN performance evaluation in various environmental scenarios has been an active research topic for researchers, and there are many existing works carried out in outdoor scenarios. On top of that, it is necessary to study how LoRa/LoRaWAN performs in indoor environments as one of the fast-growing IoT network mechanisms. However, few studies are found to work on LoRa and LoRaWAN performance evaluation in indoor scenarios. This study focuses on a real-world experiment to understand how LoRa radio signals behave according to its physical layer parameter settings.</p><p>Data is collected through real-world experiments in a campus environment. The experiments for data sample collection were conducted in September 2021 in the Purdue Campus area in West Lafayette, Indiana, United States. LoRa transceivers with the SX1276 module are deployed operating in the 915MHz frequency band on both LoRa RX and TX end nodes in this study. The data transmitted between LoRa transmitter and LoRa receiver is packet-sized (17 bytes) messages. </p><p>For data collection, LoRa module is configured with 36 PHY parameter settings – three spreading factors (7, 9, 11), three signal bandwidths (125kHz, 250kHz, 500kHz), and four coding rates (4/5, 4/6, 4/7, 4/8). Test devices are the Dragino LoRa shields equipped with SX1276 radio modules in 915MHz frequency bands. The experiment is conducted at three different distances – 10m, 20m, and 40m – between LoRa TX node and LoRa RX node in indoor office buildings in Purdue University West Lafayette Campus, US.</p> <p>The RSSI and SNR are measured to characterize the link performance of Lora. The Received Signal Strength Indication (RSSI) and Signal-to-Noise Ratio (SNR) are two Physical level indicators available on wireless radio chips. In addition to them, the LoRa communication reliability is calculated based on the Received Packet Ratio (RPR) out of transmitted packets with different PHY settings at each distance.</p>
390

Toward Improving the Internet of Things: Quality of Service and Fault Tolerance Perspectives

Alaslani, Maha S. 13 April 2021 (has links)
The Internet of Things (IoT) is a technology aimed at developing a global network of machines and devices that can interact and communicate with each other. Supporting IoT, therefore, requires revisiting the Internet’s best effort service model and reviewing its complex communication patterns. In this dissertation, we explore the unique characteristics of IoT traffic and examine IoT systems. Our work is motivated by the new capabilities offered by modern Software Defined Networks (SDN) and blockchain technology. We evaluate IoT Quality of Service (QoS) in traditional networking. We obtain mathematical expressions to calculate end-to-end delay, and dropping. Our results provide insight into the advantages of an intelligent edge serving as a detection mechanism. Subsequently, we propose SADIQ, SDN-based Application-aware Dynamic Internet of things QoS. SADIQ provides context-driven QoS for IoT applications by allowing applications to express their requirements using a high-level SQL-like policy language. Our results show that SADIQ improves the percentage of regions with an error in their reported temperature for the Weather Signal application up to 45 times; and it improves the percentage of incorrect parking statuses for regions with high occupancy for the Smart Parking application up to 30 times under the same network conditions and drop rates. Despite centralization and the control of data, IoT systems are not safe from cyber-crime, privacy issues, and security breaches. Therefore, we explore blockchain technology. In the context of IoT, Byzantine fault tolerance-based consensus protocols are used. However, the blockchain consensus layer contributes to the most remarkable performance overhead especially for IoT applications subject to maximum delay constraints. In order to capture the unique requirements of the IoT, consensus mechanisms and block formation need to be redesigned. To this end, we propose Synopsis, a novel hierarchical blockchain system. Synopsis introduces a wireless-optimized Byzantine chain replication protocol and a new probabilistic data structure. The results show that Synopsis successfully reduces the memory footprint from Megabytes to a few Kilobytes with an improvement of 1000 times. Synopsis also enables reductions in message complexity and commitment delay of 85% and 99.4%, respectively

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