<p dir="ltr">Due to the rapidly evolving landscape of the Internet of Things (IoT), efficient<br>communication solutions are increasingly sought after. The thesis delves into<br>the development and validation of two optical communication systems (IDC,<br>2021). Capitalizing on the benefits of Optical Wireless Communication (OWC)<br>and Optical Frequency Identification(OFID), two innovative optical systems are<br>introduced: a single-pixel OFID optical reader and a computer vision-based<br>communication system that utilizes an OLED tag, a camera, and a laptop as a<br>reader. These systems are designed to surpass the challenges associated with<br>existing technologies like RFID and Bluetooth, offering enhancements in<br>security, privacy, and autonomy through the integration of energy harvesting<br>technologies. Moreover, the practical application of these systems in real-world<br>settings, such as animal and object identification, highlight their versatility<br>and potential for diverse IoT applications. The prototypes presented were<br>systematically developed and subjected to a series of evaluations to assess their<br>performance. These tests focused on measuring the communication distance<br>achieved, the power consumption of the devices, and the accuracy of data<br>transmission. The experiments demonstrated the technical feasibility of the<br>systems in real IoT environments, affirming their effectiveness in overcoming<br>distance limitations and energy efficiency challenges and providing an<br>alternative solution for accurate data transmission in environments where radio<br>communications cannot operate. These findings underscore the significance and<br>applicability of optical communications.<br>highlight<br></p>

As the use of Internet of Things (IoT) devices increases, so does the number of available hardware platforms. Today there exists a broad range of hardware components that could be used to develop an IoT product and selecting the right ones is a difficult task. This thesis addresses this issue by conducting a case study where a communication controller is designed and implemented for the ArtEmis project. ArtEmis is a collaboration between universities around Europe that aims to examine the relationship between rising radon levels in ground water and the probability of forthcoming earthquakes. The case study consists of a theoretical pre-study where a survey of the current literature is conducted and establishes a set of requirements. Then, a set of hardware components are selected and used to implement a prototype. The result of the case study is a list of important parameters and potential problems which can be used to guide the development of similar systems. Two platforms based on the IoT-boards Radio sensors node model S2 and Raspberry Pi 4 model B were recommended. / I och med att antalet IoT-enheter ökar ökar också antalet tillgängliga hårdvaruplattformar. Idag finns det en mängd hårdvarukomponenter som kan användas för att utveckla IoT-produkter och det är svårt att avgöra vilka av dem som är lämpliga för varje produkt. Denna uppsats behandlar detta problem genom att utföra en fallstudie där en kommunikationskontroller designas och implementeras till ArtEmis. ArtEmis är ett samarbete mellan europeiska universitet vars syfte är att utreda sambandet mellan stigande radonnivåer i grundvattnet och sannolikheten för en framtida jordbävning. Fallstudien består av en teoretisk förstudie där en överblick av det nuvarande litteraturen ges och en kravlista för plattformen sammanställs. Sedan väljs en uppsättning hårdvarukomponenter, vilka används för att implementera en prototyp. Resultatet av fallstudien är en lista av viktiga parametrar och potentiella problem som kan användas för att vägleda utvecklingen av liknande system. Två plattformar baserade på IoT-korten Radio sensors node model S2 och Raspberry Pi 4 model B rekommenderades.

The company QTPIE conducts research on drivers and their unconscious reactions when driving. To help, they use smart devices that today must be individually handled at the start and end of a run, and have individually set timestamps, which can lead to differences between the units when data is entered and collation of the units' data after a run.   The purpose of this study is an integrated control system in the form of an Android mobile application that partly facilitates the start and end of a run, and partly synchronizes time stamps between all devices. The intention is to build a heterogeneous mobile network with a central control unit and implement time synchronization and investigate whether the heterogeneity affects the implementation of the network.   The result was an Android mobile application that controlled selected external smart devices, synchronized these, and had time synchronization built in at the start of each run. / Företaget QTPIE gör undersökningar på förare och deras omedvetna reaktioner vid körning. Till hjälp använder de smarta enheter som idag måste hanteras individuellt vid start och slut av en körning, samt har individuellt satta tidsstämplar, vilket kan leda till differenser mellan enheterna vid datainmatning och sammanstrålning av enheternas data efter en körning.  Avsikten med den här studien är ett integrerat styrsystem i form av en Android mobilapplikation som dels underlättar vid start och slut av en körning, dels synkroniserar tidsstämplar mellan alla enheter. Avsikten är att bygga upp ett heterogent mobilt nätverk med en central kontrollenhet samt implementera tidssynkronisering och undersöka om heterogeniteten påverkar implementeringen av nätverket.   Resultatet blev en Android mobilapplikation som styrde valda externa smarta enheter, synkroniserade dessa samt hade tidssynkronisering inbyggt vid start av varje körning.

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There is a remarkable growth in the field of Information Communication Technology (ICT) in Developing Countries (DCs). Telecommunication is one of the areas where ICT is recording an ongoing rapid change. Mobile phones are becoming pervasive in daily scenario; and among the beneficiaries of this are farmers. Farmers are using mobile phones in executing their farming business and daily life. At the same time, Wireless Sensor Networks (WSNs) are also showing a result in developed part of our world. WSNs potential in sensing various environmental condition, their affordability and applicability motivated conducting of this master thesis. Therefore, the objective of conducting this master thesis is to investigate and identify how the use of mobile phones in conjunction with WSN enable farmers in Ethiopia monitor and control their farm field. We use firsthand qualitative data we gathered during our field work in Ethiopia to design our proposed prototype. Functional requirements and system design guideless are obtained from observation we make and interviews we carry out on irrigation based farmers around town of Meki in region of Oromia. We use our prototype to demonstrate and evaluate how irrigation based farmers benefit from existence of such system.

Data sensing and retrieval in WSNs have a great applicability in military, environmental, medical, home and commercial applications. In query-based WSNs, a user would issue a query with QoS requirements in terms of reliability and timeliness, and expect a correct response to be returned within the deadline. Satisfying these QoS requirements requires that fault tolerance mechanisms through redundancy be used, which may cause the energy of the system to deplete quickly. This dissertation presents the design and validation of adaptive fault tolerant QoS control algorithms with the objective to achieve the desired quality of service (QoS) requirements and maximize the system lifetime in query-based WSNs. We analyze the effect of redundancy on the mean time to failure (MTTF) of query-based cluster-structured WSNs and show that an optimal redundancy level exists such that the MTTF of the system is maximized. We develop a hop-by-hop data delivery (HHDD) mechanism and an Adaptive Fault Tolerant Quality of Service Control (AFTQC) algorithm in which we utilize "source" and "path" redundancy with the goal to satisfy application QoS requirements while maximizing the lifetime of WSNs. To deal with network dynamics, we investigate proactive and reactive methods to dynamically collect channel and delay conditions to determine the optimal redundancy level at runtime. AFTQC can adapt to network dynamics that cause changes to the node density, residual energy, sensor failure probability, and radio range due to energy consumption, node failures, and change of node connectivity. Further, AFTQC can deal with software faults, concurrent query processing with distinct QoS requirements, and data aggregation. We compare our design with a baseline design without redundancy based on acknowledgement for data transmission and geographical routing for relaying packets to demonstrate the feasibility. We validate analytical results with extensive simulation studies. When given QoS requirements of queries in terms of reliability and timeliness, our AFTQC design allows optimal "source" and "path" redundancies to be identified and applied dynamically in response to network dynamics such that not only query QoS requirements are satisfied, as long as adequate resources are available, but also the lifetime of the system is prolonged. / Ph. D.

Existen muchos trabajos relacionados con el diseño y desarrollo de nodos sensores, donde se presentan gran variedad de aplicaciones. Las redes de sensores inalámbricos pueden facilitarnos y mejorar algunos aspectos de nuestra vida diaria. Es fácil, pensar que si este tipo de dispositivo es tan beneficioso para nosotros y para el entorno donde vivimos, su precio debería ser relativamente barato. Pero podemos comprobar que esto no es así. ¿Por qué estos dispositivos son tan caros? ¿Sería posible desarrollar dispositivos con las mismas capacidades y precios más económicos? ¿Cómo puedo fabricar mis nodos sensores de bajo coste? Esta tesis responde a estas preguntas y muestra algunas de las muchas aplicaciones que los nodos sensores pueden tener. En esta tesis hemos propuesto (e implementado en algunos casos) el desarrollo de nodos sensores para la monitorización del medio, a partir de dispositivos de bajo coste. Para la implementación de un nodo sensor, y en definitiva la red que une a todos estos nodos, es importante conocer el medio donde trabajarán. A lo largo de este documento se presentan las investigaciones llevadas a cabo para el desarrollo de sensores en tres ámbitos de aplicación. En el primero de ellos, se desarrollan dispositivos multisenores para la monitorización del medio. La aplicación de las redes de sensores inalámbricas al medio natural, precisa un estudio de cómo se ven afectadas las señales, en función de la distancia, vegetación, humedad del ambiente, etc. Focalizamos nuestros desarrollos en la verificación de incendios en zonas rurales y en el control de plagas en viñedos donde la detección precoz de estos eventos genera elevados ahorros económicos. También proponemos el desarrollo de una red de collares sensores para ganado domestico, que nos ayudará a reducir y prevenir en muchos casos, los ataques de lobos y hurtos de crías. Por último, dentro de este grupo, presentamos una red permite detectar anomalía de los materiales en edificios y red de sensores que nos permite monitorizar las personas mayores o deficientes, que se mueven junto con un grupo, en una excursión o actividad. El segundo grupo de aplicaciones, hace referencia a la monitorización de espacios en entornos de interior. Para ello hemos analizado el comportamiento de las señales inalámbricas en diferentes escenarios. Los resultados, nos han permitido extraer un nuevo método de diseño de las redes inalámbricas en interiores. Nuestro método, permite definir la mejor ubicación de los dispositivos de red y nodos sensores en interiores con un ahorro en el número de sensores del 15%. Por último, se presenta el estudio sobre las comunicaciones subacuáticas basadas en las ondas electromagnéticas donde analizamos la dependencia de las comunicaciones subacuáticas en agua dulce en función de la frecuencia, temperatura, tasas de transferencia de datos y modulación. Relacionado con el medio subacuático, presentamos 2 propuestas. La primera de ellas hace referencia a la implementación de una red de sensores para granjas marinas que nos permite reducir la cantidad de residuos depositados en el lecho marino y reducir el porcentaje de comida desperdiciada. La segunda propuesta es el desarrollo de dos sensores oceanográficos que nos permitirían controlar la cantidad de comida y heces depositadas en el suelo y controlar la turbidez del agua de manera muy simple y económica Todos estos desarrollos y propuestas, han estado precedidos por un exhaustivo estudio sobre los problemas energéticos que las redes de sensores inalámbricas presentan y las técnicas que pueden emplearse, para prolongar la vida útil de la red y mejorar su estabilidad. / There are many works related to the design and development of sensor nodes which present several applications. Wireless sensor networks can facilitate and improve some aspects of our daily lives. It is easy to think that if this type of device is so beneficial to us and to our environment, its price should be relatively cheap. But we can see that this is not true. Why these devices are so expensive? Would it be possible to develop devices with the same capabilities and lower prices? How can I make my low-cost sensor nodes? This dissertation answers these questions and shows some of the many applications that sensor nodes may have. In this dissertation, we propose (and implement in some cases) the development of sensor nodes for environmental monitoring, from low-cost devices. For the implementation of a sensor node and network which joins all these nodes, it is important to know the environment where they will work. Throughout this dissertation, we present the research carried out for the development of sensors in three main application areas. In the first of these areas, we present multisensor devices developed for environmental monitoring. The application of wireless sensor networks to the environment requires a study of how signals are affected depending on the distance, vegetation, ambient humidity, etc. We focus our developments on the fire detection in rural areas and on the control of pests in vineyards where the early detection of these events generates high economic savings. We also propose the development of a sensor network which will help us to reduce and prevent wolves¿ attacks and theft in livestock. Finally, within this group, we present a network to detect material anomalies in building and a sensor network which allows us to monitor the elderly or disabled people who move along with a group on a tour or activity. The second group of applications is related to the monitoring of spaces in indoor environments. For this, we analyze the behavior of wireless signals in different scenarios. These results allowed us to extract a new method for designing wireless networks in indoor environments. Our method allows defining the best location of network devices and sensor nodes indoors saving 15% of the sensors needed. Finally, we present a study on underwater freshwater communications based on electromagnetic waves, where we analyze the dependency of underwater communications as a function of working frequency, temperature, data transfer rates and modulation. Related to underwater environment, we present two proposals. First one refers to the implementation of a sensor network for marine farms which allows us to reduce the amount of waste deposited on the seabed and reduce the percentage of wasted food. The second proposal is the development of two oceanographic sensors which allow us to control the amount of food and feces deposited in seabed and the water turbidity control in a very simple and inexpensive way. All these developments and proposals have been preceded by a comprehensive study on the energy problems in wireless sensor networks. We have also presented several techniques which can be used to prolong the network lifetime and improve its stability. / Sendra Compte, S. (2013). Deployment of Efficient Wireless Sensor Nodes for Monitoring in Rural, Indoor and Underwater Environments [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/32279

Wireless sensor networks (WSNs) are frequently deployed unattended and can be easily captured or compromised. Once compromised, intrusion prevention methods such as encryption can no longer provide any protection, as a compromised node is considered a legitimate node and possesses the secret key for decryption. Compromised nodes are essentially inside attackers and can perform various attacks to break the functionality of the system. Thus, for safety-critical WSNs, intrusion detection techniques must be used to detect and remove inside attackers and fault tolerance techniques must be used to tolerate inside attackers to prevent security failure. In this dissertation research, we develop a class of dynamic redundancy management algorithms for redundancy management of multisource multipath routing for fault and intrusion tolerance, and majority voting for intrusion detection, with the goal of maximizing the WSN lifetime while satisfying application quality-of-service and security requirements, for base station based WSNs, homogeneous clustered WSNs, and heterogeneous clustered WSNs. By means of a novel model-based analysis methodology based on probability theory, we model the tradeoff between energy consumption vs. reliability, timeliness and security gain, and identify the optimal multisource multipath redundancy level and intrusion detection settings for maximizing the lifetime of the WSN while satisfying application quality-of-service requirements. A main contribution of our research dissertation is that our dynamic redundancy management protocol design addresses the issues of "how many paths to use" and "what paths to use" in multisource multipath routing for intrusion tolerance. Another contribution is that we take an integrated approach combining intrusion detection and tolerance in the protocol design to address the issue of "how much intrusion detection is enough" to prevent security failure and prolong the WSN lifetime time. We demonstrate resiliency of our dynamic redundancy management protocol design for intrusion detection and tolerance against sophisticated attacker behaviors, including selective and random capture, as well as persistent, random, opportunistic and insidious attacks, by model-based performance analysis with results supported by extensive simulation based on ns3. / Ph. D.

The emergence of smart cities as a field of study focuses on integrating hardware and data-driven solutions to enhance the efficiency, sustainability, and quality of life in urban areas. A smart city looks to integrate various Internet of Things (IoT) technologies such as sensor hardware, wireless communication networks, and data analysis methods into urban infrastructure and services optimization. Smart city initiatives typically aim to address challenges related to environmental monitoring, energy generation, waste management, and healthcare, among others. At its core, the field of smart cities fuses various elements of wireless IoT sensor technologies in ways that aim to create more livable and resilient urban environments for residents. The work outlined in this thesis looks to investigate and overcome some of the challenges involved with wide-scale implementation of IoT devices in an urban environment. The thesis begins by defining a "smart city" and discussing the current status of IoT devices development and their applications for smart cities. Included in this analysis is an outline of common wireless communication protocols, sensor integration methodologies, and motivations for biomedical and environmental applications of wireless sensor networks. Next, this thesis presents advancements in the integration of implantable biomedical devices with wireless sensor tags. These devices were realized with Bluetooth low energy (BLE) and long range radio wide area network (LoRaWAN) wireless communication protocols in form factors appropriate for rodent models. To enable these implantable devices, a novel design methodology for biocompatible antennas was developed and implemented in a LoRaWAN data link. In addition, the behavioral effects of various commercial printed circuit board technologies were studied in rodents in an effort to study the least invasive methods to design implantable devices. Next this thesis discusses IoT applications in urban soils health monitoring. In this work, low cost soil sensors were developed with BLE and LoRaWAN varieties. These sensors are capable of measuring light, humidity, temperature, and nutrient concentration (Nitrogen, Phosphorus, and Potassium) to determine changes in soil health. Additionally, these sensors were integrated with a dendrometer to record weather patterns remotely over the course of a few months. Finally, this thesis concludes with a study on the network characteristics of a LoRaWAN communication link on the physical (PHY) and medium access control (MAC) layers. In this study, the entirety of New York City's Upper West Side was used as an urban test bed to fully measure the performance of long-range LoRaWAN communication links in a dense urban environment. This characterization compared devices from different application spaces and measured their power consumption, signal to noise ratio (SNR), received signal strength indicator (RSSI), and approximate distance from a receiver to analyze device performance over a majority of northern Manhattan.