Light Fidelity (Li-Fi) prototype with Raspberry Pi

With globalisation and the thirst for connectivity across society, the demand placed on wireless infrastructure and the associated resource is growing exponentially. Very soon this resource will reach saturation point, due to the finite bandwidth available in the Radio Frequency (RF) spectrum. A method of countering the impending saturation needs to be found. That method can be Visible Light Communication (VLC). Light Fidelity (Li-Fi) is a research field within VLC that utilises the visible light band within the electromagnetic wave spectrum. This band is 10,000 times larger than the RF band and cannot be ‘leased’ or saturated with users. Light waves can be modulated to carry an enormous amount ofsimultaneous data, at speeds faster than current consumer equipment can handle. This Dissertation describes in detail the research, construction and testing of a Li-Fi prototype using Raspberry Pi. The prototype is compact, low cost, uses accessible components and provides a solid foundation for other students to follow on with further work in this field. The prototype successfully demonstrates the principle of Visible Light Communication and shows the viability of using Python for coding, SPI for data transfer and lists suitable electronic components to process bit-wise data signals. The prototype shows that while it is possible to use addressable LED’sas the transmitting element, the Dissertation concludes that they are not suitable outside of a heavily constrained environment

Coverage measurements of NB-IoT technology

Abstract. The narrowband internet of things (NB-IoT) is a cellular radio access technology that provides seamless connectivity to wireless IoT devices with low latency, low power consumption, and long-range coverage. For long-range coverage, NB-IoT offers a coverage enhancement (CE) mechanism that is achieved by repeating the transmission of signals. Good network coverage is essential to reduce the battery usage and power consumption of IoT devices, while poor network coverage increases the number of repetitions in transmission, which causes high power consumption of IoT devices. The primary objective of this work is to determine the network coverage of NB-IoT technology under the University of Oulu’s 5G test network (5GTN) base station. In this thesis work, measurement results on key performance indicators such as reference signal received power (RSRP), reference signal received quality (RSRQ), received signal strength indicator (RSSI), and signal to noise plus interference (SINR) have been reported. The goal of the measurement is to find out the NB-IoT signal strength at different locations, which are served by the 5GTN cells configured with different parameters, e.g., Tx power levels, antenna tilt angles. The signal strength of NB-IoT technology has been measured at different places under the 5GTN base station in Oulu, Finland. Drive tests have been conducted to measure the signal strength of NB-IoT technology by using the Quectel BG96 module, Qualcomm kDC-5737 dongle and Keysight Nemo Outdoor software. The results have shown the values of RSRP, RSRQ, RSSI, and SINR at different locations within several kilometres of the 5GTN base stations. These values indicate the performance of the network and are used to assess the performance of network services to the end-users. In this work, the overall performance of the network has been checked to verify if network performance meets good signal levels and good network coverage. Relevant details of the NB-IoT technology, the theory behind the signal coverage and comparisons with the measurement results have also been discussed to check the relevance of the measurement results

Low cost passive radar through software defined radio

Passive radars utilise existing terrestrial radio signals, such as those produced by radio or television stations, to track objects within their range. This project aims to determine the suitability of low cost USB TV tuners as hardware receivers for a Software Defined Radio (SDR) based passive radar receiver. Subsequently determining its effectiveness in producing inverse synthetic aperture radar images using data collected from Digital Television signals. Since the initial identification of passive radar, Militaries the world over have been using it as a part of electronic warfare. The evolution of SDR has enabled greater access to the technologies required to implement passive radar, with the greatest limitation being the cost of the required hardware. The availability of low cost hardware was therefore investigated to determine its suitability and subsequently the availability of passive radar to a wider audience. Research was conducted into the available SDR receivers, and comparison of specifications was made against the low cost receiver used in the project. A functional hardware platform based around the Realtek RTL2832U chipset has been developed to determine its suitability as a low cost receiver verifying its ability to coherently receive radio signals for target identification. A complex ambiguity function was implemented to interpret sampled data windows, with the output of these windows to be compared to the requirements for an inverse synthetic aperture radar input, thus determining the suitability of the device. Interpretation of the received data has identified that although the hardware is capable, a real time implementation of data processing is not yet possible, impeding the ability to determine the suitability of the receiver as an inverse synthetic aperture receiver. The results of testing show that the hardware is capable of receiving and producing radar images, however due to the bandwidth of DVB-T signals , and the bandwidth limitations inherent in RTL-SDR dongles, they have proven not to be suitable for DVB-T based inverse synthetic aperture radar receivers

Integration and characterisation of the performance of fifth-generation mobile technology (5g) connectivity over the University of Oulu 5g test network (5gtn) for cognitive edge node based on fractal edge platform

Abstract. In recent years, there has been a growing interest in cognitive edge nodes, which are intelligent devices that can collect and process data at the edge of the network. These nodes are becoming increasingly important for various applications such as smart cities, industrial automation, and healthcare. However, implementing cognitive edge nodes requires a reliable and efficient communication network. Therefore, this thesis assesses the performance of direct cellular (5G) and IEEE 802.11-based Wireless Local Area Network (WLAN) technology for three network architectures, which has the potential to offer low-latency, high-throughput and energy-efficient communication, for cognitive edge nodes. The study focused on evaluating the network performance metrics of throughput, latency, and power consumption for three different FRACTAL-based network architectures. These architectures include IEEE 802.11-based last mile, direct cellular (5G) backbone, and IEEE 802.11-based last mile over cellular (5G) backbone topologies. This research aims to provide insights into the performance of 5G technology for cognitive edge nodes. The findings suggest that the power consumption of IEEE 802.11-enabled nodes was only slightly higher than the reference case, indicating that it is more energy-efficient than 5G-enabled nodes. Additionally, in terms of latency, IEEE 802.11 technology may be more favourable. The throughput tests revealed that the cellular (5G) connection exhibited high throughput for communication between a test node and an upper-tier node situated either on the internet or at the network edge. In addition, it was found that the FRACTAL edge platform is flexible and scalable, and it supports different wireless technologies, making it a suitable platform for implementing cognitive edge nodes. Overall, this study provides insights into the potential of 5G technology and the FRACTAL edge platform for implementing cognitive edge nodes. The results of this research can be valuable for researchers and practitioners working in the field of wireless communication and edge computing, as it sheds light on the feasibility and performance of these technologies for implementing cognitive edge nodes in various applications

A High-speed Reconfigurable Free Space Optical Communication System Utilizing Software Defined Radio Environment

Free space optical (FSO) communication allows for high-speed data transmissions while also being extremely cost-effective by using visible or infrared wavelengths to transmit and receive data wirelessly through the free space channel. However, FSO links are highly susceptible to the effects of the atmosphere, particularly turbulence, smoke, and fog. On the other hand, FSO itself does not provide enough flexibility to address the issue of such blockage and obstruction caused by objects and atmospheric conditions. This research investigates, proposes, and evaluates a software defined multiple input multiple output (MIMO) FSO system to ensure link availability and reliability under weather conditions as part of the last mile access in the 5th generation, 6th generation, and beyond. Software defined radio (SDR) technology is adopted in order to provide a certain degree of flexibility to the optical wireless communications system. The scope of this research focuses on the design, validation, implementation, and evaluation of a novel adaptive switching algorithm i.e., activating additional transmitters of a MIMO FSO system using a software defined ecosystem. The main issues are the compactness of the experimental design; the limitation of software-oriented signal generation; robustness; reliability; and the quality of service. As part of the system design, the thresholding method, a decision-making process via the feedback link, and a spatial diversity technique is adopted to carry out the adaptive switching. The adaptive switching is performed via a feedback link in which the atmospheric loss and scintillation index are calculated for fog and turbulence respectively. The initial design is implemented in SDR/ GNURadio for a real-time emulation of the proposed system to enhance the system flexibility of a traditional MIMO FSO system. A bit-by-bit comparison is performed with the GNURadio signal processing block and BERT for a real-time BER estimation. However, based on the initial results, the switching mechanism can only overcome the effect of turbulence at a certain level. A new design to mainly mitigate the varying fog conditions is proposed based on the SDR-based adaptive switching for a gigabit ethernet (GbE) MIMO FSO system and tested in a 5 m dedicated atmospheric chamber. The proposed system is implemented using off-the-shelf components such as a media converter, small form pluggable transceivers, optical switch, and power meter to estimate the channel state information. A new Schmitt trigger-based thresholding method is also introduced. The proposed software defined GbE MIMO FSO with an adaptive switching algorithm is fabricated, implemented, and investigated. The results are also compared with the real-time simulated data. Since the purpose of this Ph.D. is to explain and demonstrate the proof of concept for the proposed SDR-MIMO FSO system, the emphasis has been on the design, evaluation, and minimal performance requirements rather than maximizing the data rate. The outcome of the thesis will be a huge degree of flexibility and mitigation property MIMO FSO can offer with the help of SDR. It will be shown that the designed system has the capability to provide data transmission with 99.999% availability with a packet error rate and data rate of 7.2 ×10−2 and ~120 Mbps respectively, under extremely harsh fog conditions with visibility V of < 11 m

Electronic Devices for the Combination of Electrically Controlled Drug Release, Electrostimulation, and Optogenetic Stimulation for Nerve Tissue Regeneration

[ES] La capacidad de las células madre para proliferar formando distintas células especializadas les otorga la potencialidad de servir de base para terapias efectivas para patologías cuyo tratamiento era inimaginable hasta hace apenas dos décadas. Sin embargo, esta capacidad se encuentra mediada por estímulos fisiológicos, químicos, y eléctricos, específicos y complejos, que dificultan su traslación a la rutina clínica. Por ello, las células madre representan un campo de estudio en el que se invierten amplios esfuerzos por parte de la comunidad científica. En el ámbito de la regeneración nerviosa, para modular su desarrollo y diferenciación el tratamiento farmacológico, la electroestimulación, y la estimulación optogenética son técnicas que están consiguiendo prometedores resultados. Es por ello por lo que en la presente tesis se ha desarrollado un conjunto de sistemas electrónicos para permitir la aplicación combinada de estas técnicas in vitro, con perspectiva a su aplicación in vivo. Hemos diseñado una novedosa tecnología para la liberación eléctricamente controlada de fármacos. Esta tecnología está basada en nanopartículas de sílice mesoporosa y puertas moleculares de bipiridina-heparina. Las puertas moleculares son electroquímicamente reactivas, y encierran los fármacos en el interior de las nanopartículas, liberándolos ante un estímulo eléctrico. Hemos caracterizado esta tecnología, y la hemos validado mediante la liberación controlada de rodamina en cultivos celulares de HeLa. Para la combinación de liberación controlada de fármacos y electroestimulación hemos desarrollado dispositivos que permiten aplicar los estímulos eléctricos de forma configurable desde una interfaz gráfica de usuario. Además, hemos diseñado un módulo de expansión que permite multiplexar las señales eléctricas a diferentes cultivos celulares. Además, hemos diseñado un dispositivo de estimulación optogenética. Este tipo de estimulación consiste en la modificación genética de las células para que sean sensibles a la radiación lumínica de determinada longitud de onda. En el ámbito de la regeneración de tejido mediante células precursoras neurales, es de interés poder inducir ondas de calcio, favoreciendo su diferenciación en neuronas y la formación de circuitos sinápticos. El dispositivo diseñado permite obtener imágenes en tiempo real mediante microscopía confocal de las respuestas transitorias de las células al ser irradiadas. El dispositivo se ha validado irradiando neuronas modificadas con luz pulsada de 100 ms. También hemos diseñado un dispositivo electrónico complementario de medida de irradiancia con el doble fin de permitir la calibración del equipo de irradiancia y medir la irradiancia en tiempo real durante los experimentos in vitro. Los resultados del uso de los bioactuadores en procesos complejos y dinámicos, como la regeneración de tejido nervioso, son limitados en lazo abierto. Uno de los principales aspectos analizados es el desarrollo de biosensores que permitiesen la cuantización de ciertas biomoléculas para ajustar la estimulación suministrada en tiempo real. Por ejemplo, la segregación de serotonina es una respuesta identificada en la elongación de células precursoras neurales, pero hay otras biomoléculas de interés para la implementación de un control en lazo cerrado. Entre las tecnologías en el estado del arte, los biosensores basados en transistores de efecto de campo (FET) funcionalizados con aptámeros son realmente prometedores para esta aplicación. Sin embargo, esta tecnología no permitía la medición simultánea de más de una biomolécula objetivo en un volumen reducido debido a las interferencias entre los distintos FETs, cuyos terminales se encuentran inmersos en la solución. Por ello, hemos desarrollado instrumentación electrónica capaz de medir simultáneamente varios de estos biosensores, y la hemos validado mediante la medición simultánea de pH y la detección preliminar de serotonina y glutamato.[CA] La capacitat de les cèl·lules mare per a proliferar formant diferents cèl·lules especialitzades els atorga la potencialitat de servir de base per a teràpies efectives per a patologies el tractament de les quals era inimaginable fins fa a penes dues dècades. No obstant això, aquesta capacitat es troba mediada per estímuls fisiològics, químics, i elèctrics, específics i complexos, que dificulten la seua translació a la rutina clínica. Per això, les cèl·lules mare representen un camp d'estudi en el qual s'inverteixen amplis esforços per part de la comunitat científica. En l'àmbit de la regeneració nerviosa, per a modular el seu desenvolupament i diferenciació el tractament farmacològic, l'electroestimulació, i l'estimulació optogenética són tècniques que estan aconseguint prometedors resultats. És per això que en la present tesi s'ha desenvolupat un conjunt de sistemes electrònics per a permetre l'aplicació combinada d'aquestes tècniques in vitro, amb perspectiva a la seua aplicació in vivo. Hem dissenyat una nova tecnologia per a l'alliberament elèctricament controlat de fàrmacs. Aquesta tecnologia està basada en nanopartícules de sílice mesoporosa i portes moleculars de bipiridina-heparina. Les portes moleculars són electroquímicament reactives, i tanquen els fàrmacs a l'interior de les nanopartícules, alliberant-los davant un estímul elèctric. Hem caracteritzat aquesta tecnologia, i l'hem validada mitjançant l'alliberament controlat de rodamina en cultius cel·lulars de HeLa. Per a la combinació d'alliberament controlat de fàrmacs i electroestimulació hem desenvolupat dispositius que permeten aplicar els estímuls elèctrics de manera configurable des d'una interfície gràfica d'usuari. A més, hem dissenyat un mòdul d'expansió que permet multiplexar els senyals elèctrics a diferents cultius cel·lulars. A més, hem dissenyat un dispositiu d'estimulació optogenètica. Aquest tipus d'estimulació consisteix en la modificació genètica de les cèl·lules perquè siguen sensibles a la radiació lumínica de determinada longitud d'ona. En l'àmbit de la regeneració de teixit mitjançant cèl·lules precursores neurals, és d'interés poder induir ones de calci, afavorint la seua diferenciació en neurones i la formació de circuits sinàptics. El dispositiu dissenyat permet obtindré imatges en temps real mitjançant microscòpia confocal de les respostes transitòries de les cèl·lules en ser irradiades. El dispositiu s'ha validat irradiant neurones modificades amb llum polsada de 100 ms. També hem dissenyat un dispositiu electrònic complementari de mesura d'irradiància amb el doble fi de permetre el calibratge de l'equip d'irradiància i mesurar la irradiància en temps real durant els experiments in vitro. Els resultats de l'ús dels bioactuadors en processos complexos i dinàmics, com la regeneració de teixit nerviós, són limitats en llaç obert. Un dels principals aspectes analitzats és el desenvolupament de biosensors que permeteren la quantització de certes biomolècules per a ajustar l'estimulació subministrada en temps real. Per exemple, la segregació de serotonina és una resposta identificada amb l'elongació de les cèl·lules precursores neurals, però hi ha altres biomolècules d'interés per a la implementació d'un control en llaç tancat. Entre les tecnologies en l'estat de l'art, els biosensors basats en transistors d'efecte de camp (FET) funcionalitzats amb aptàmers són realment prometedors per a aquesta aplicació. No obstant això, aquesta tecnologia no permetia el mesurament simultani de més d'una biomolècula objectiu en un volum reduït a causa de les interferències entre els diferents FETs, els terminals dels quals es troben immersos en la solució. Per això, hem desenvolupat instrumentació electrònica capaç de mesurar simultàniament diversos d'aquests biosensors i els hem validat amb mesurament simultani del pH i la detecció preliminar de serotonina i glutamat.[EN] The stem cells' ability to proliferate to form different specialized cells gives them the potential to serve as the basis for effective therapies for pathologies whose treatment was unimaginable until just two decades ago. However, this capacity is mediated by specific and complex physiological, chemical, and electrical stimuli that complicate their translation to clinical routine. For this reason, stem cells represent a field of study in which the scientific community is investing a great deal of effort. In the field of nerve regeneration, to modulate their development and differentiation, pharmacological treatment, electrostimulation, and optogenetic stimulation are techniques that are achieving promising results. For this reason, we have developed a set of electronic systems to allow the combined application of these techniques in vitro, with a view to their application in vivo. We have designed a novel technology for the electrically controlled release of drugs. This technology is based on mesoporous silica nanoparticles and bipyridine-heparin molecular gates. The molecular gates are electrochemically reactive and entrap the drugs inside the nanoparticles, releasing them upon electrical stimulus. We have characterized this technology and validated it by controlled release of rhodamine in HeLa cell cultures. For combining electrostimulation and controlled drug release we have developed devices that allow applying the different electrical stimuli in a configurable way from a graphical user interface. In addition, we have designed an expansion module that allows multiplexing electrical signals to different cell cultures. In addition, we have designed an optogenetic stimulation device. This type of stimulation consists of genetically modifying cells to make them sensitive to light radiation of a specific wavelength. In tissue regeneration using neural precursor cells, it is interesting to be able to induce calcium waves, favoring the cell differentiation into neurons and the formation of synaptic circuits. The designed device enable the obtention of real-time images through confocal microscopy of the transient responses of cells upon irradiation. The device has been validated by irradiating modified neurons with 100 ms pulsed light stimulation. We have also designed a complementary electronic irradiance measurement device to allow calibration of the irradiator equipment and measuring irradiance in real time during in vitro experiments. The results of using bioactuators in complex and dynamic processes, such as nerve tissue regeneration, are limited in an open loop. One of the main aspects analyzed is the development of biosensors that would allow quantifying of specific biomolecules to adjust the stimulation provided in real time. For instance, serotonin secretion is an identified response of neural precursor cells elongation, among other biomolecules of interest for the implementation of a closed-loop control. Among the state-of-the-art technologies, biosensors based on field effect transistors (FETs) functionalized with aptamers are promising for this application. However, this technology did not allow the simultaneous measurement of more than one target biomolecule in a small volume due to interferences between the different FETs, whose terminals are immersed in the solution. This is why we have developed electronic instrumentation capable of simultaneously measuring several of these biosensors, and we have validated it with the simultaneous pH measurement and the preliminary detection of serotonin and glutamate.Monreal Trigo, J. (2023). Electronic Devices for the Combination of Electrically Controlled Drug Release, Electrostimulation, and Optogenetic Stimulation for Nerve Tissue Regeneration [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/19384

Establishing and optimising unmanned airborne relay networks in urban environments

This thesis assesses the use of a group of small, low-altitude, low-power (in terms of communication equipment), xed-wing unmanned aerial vehicles (UAVs) as a mobile communication relay nodes to facilitate reliable communication between ground nodes in urban environments. This work focuses on enhancing existing models for optimal trajectory planning and enabling UAV relay implementation in realistic urban scenarios. The performance of the proposed UAV relay algorithms was demonstrated and proved through an indoor simulated urban environment, the rst experiment of its kind.The objective of enabling UAV relay deployment in realistic urban environments is addressed through relaxing the constraints on the assumptions of communication prediction models assumptions, reducing knowledge requirements and improving prediction efficiency. This thesis explores assumptions for urban environment knowledge at three different levels: (i) full knowledge about the urban environment, (ii) partially known urban environments, and (iii) no knowledge about the urban environment. The work starts with exploring models that assume the city size, layout and its effects on wireless communication strength are known, representing full knowledge about the urban environment. [Continues.]</div

Development and fabrication of ammonia gas leakage detection and monitoring system

In industries that use hazardous gases in significant amounts for their diverse processes, there are high-risk variables involved. People may fail to detect or monitor the emission of these gases on a regular basis before it becomes dangerous. Sensors are required to continuously monitor leaks and notify users to potential hazards. The purpose of the project is to improve irrelevant measurement methods that are held or installed on walls and serve merely to measure. The project incorporates Internet-of-Thing’s technology to monitor sensor readings from a safe distance, locate areas where ammonia gas is leaking based on pressure sensor readings, and includes a prevention system that serves as feedback that responds to sensor readings to control water pumps, fans, and solenoid valves to control ammonia gas leakage. Various sensor values are received and processed using microprocessors. This project design and fabrication of an ammonia gas leakage detection and monitoring system employs the ESP 32 as a microcontroller due to its low-power, low-cost system that includes built-in Wi-Fi and dual-mode Bluetooth. The Air Quality Sensor MQ-135 also serves as an Ammonia Gas Sensor, detecting gas leakage when ammonia gas leaks. The project system focuses on the transfer of data from the sensing unit to the broker, where it is kept momentarily in the Blynk app but can be stored for a long time and exported in the web Thingspeak, as well as the GPS system, gives precise latitude and longitude information. The data is displayed on a mobile web and application, which users can use to monitor sensor readings. Data is transmitted via the nodeMCU, which reads data from inputs and outputs and sends it to Blynk applications and the Thingspeak protocol. The pressure sensor is used to identify specific parts of ammonia gas leakage. The siren alarm and LEDs are used to notify employees or officials. This ammonia gas leakage detection and monitoring system project was completed successfully. There are improvements can be done for future development on this prototype such as to fabrication ammonia plant using non corossive material and use industrial sensor to make reading for accurate ammonia gas detection

Long Distance, Low Data Rate Packet Transmission at 868 MHz: Protocol Design and Implementation

Masteroppgave informasjons- og kommunikasjonsteknologi - Universitetet i Agder 2016Data transmission over wireless networks can be achieved in various ways. Some of these technologies are feasible in many real life scenarios, but there are many consequences we have to consider in this field, such as packet loss, quality degradation of radio signal over distance incrementation, ambient noise, transmission delay and etc. For the low data rate packet transmission, to adapt and to address IoT is one of the most discussed topics nowadays, especially in terms of transmission protocol design and the implementation of that design in real life scenarios. Transmitting packets in low data rate over long distance efficiently is becoming an important issue in this fastpaced modern world. Although various work has been done individually on low data rate packet transmission and protocol to achieve longer distance. Our objective is to combine both options in the same protocol design with diverse form of services. In this project, we design an embedded solution and implement our own transmission schemes based on Raspberry Pi micro-controller to send low date rate packets via radio modules that operating on 868 MHz band to achieve long distance. We embed and implement the design with low cost and low power components and send real-time services such as GPS co-ordinates, temperature, image and etc. over wireless network. Then we develop our design to relay the transmission from the source node to the destination node by using a forwarding node in between them, which helps us to achieve further distance. These transmission schemes have the ability to respond to each other with acknowledgements assuring the successful transactions between the nodes and for the request of retransmissions. In addition, the schemes are developed further to a new scheme where the retransmission will occur with an adaptive data rate at the end of the transmission process to ensure the successful transfer of a large file. At the end, we collect and examine the data on the sender and receiver ends and calculate parameters such as packet loss rate, transmission delay, etc., by running the tests in di↵erent scenarios and optimising the experimental results. The results show that with these transmission schemes the packets can be transmitted to long distance in low data rate and with a small amount of packet loss rate