The thesis is about the construction of a GPS-tracker that can read NFC (Near Field Communication)-tags and communicate with LoRa (Long Range) and BLE (Bluetooth low energy) and investigate which of the components in the GPS-tracker that consumes most power. The usage area for the GPS-tracker is to make the work on disaster affected sites more efficient and secure by having an operation leader that can organizing the operation with help of the information provided by the GPS-trackers that are placed on the injured people and recuing personnel. The GPS-tracker is built around the sensor development kit Thingy:52 from Nordic Semiconductor. The Firmware (FW) for the Thingy:52 is developed by modifying the provided factory FW by Nordic Semiconductor. The GPS-module and the NFC-reader showed to be the most power consuming parts of the GPS-tracker. An energy optimization proposal for these parts are given in the report. A proposal to a circuit diagram for the GPS-tracker is also given in the report, that can be used for future miniaturization of the GPS-tracker. / Projektet har innefattat att ta fram en GPS-spårsändare som kan läsa NFC (Near Field Communication)-taggar, kommunicera med LoRa (Long Range) och BLE (Bluetooth low energy) samt undersöka vilka av GPS-spårsändarens olika delar som konsumerar mest energi. Användningsområdet för GPS-spårsändaren är att effektivisera räddningsinsatser på skadeplatser där det finns skadade människor exempelvis efter en översvämning eller terroristattack. Effektiviseringen är tänkt ska ske genom att en operationsledare styr räddningsinsatsen med hjälp av informationen som skickas från GPS-spårsändarna som kommer att bäras av skadade personer och räddningspersonalen på skadeplatsen. GPS-spårsändaren är utvecklad kring sensorutvecklings kittet Thingy:52 från Nordic Semiconductor och dess mjukvara har utvecklats genom att modifiera den mjukvara som Nordic Semiconductor har utvecklat för Thingy:52. De delar av GPS-spårsändaren som visade sig konsumera mest energi var GPS-modulen och NFC-läsaren. I rapporten finns energioptimerings förslag för dessa delar. Rapporten innehåller även ett förslag till ett kretsschema för GPS-spårsändaren som kan användas vid framtida miniatyrisering av GPS-spårsändaren.

Une grande partie des nouvelles générations d'objets connectés ne pourra se développer que s'il est possible de les rendre entièrement autonomes sur le plan énergétique. Même si l'utilisation de batteries ou de piles résout une partie de ce problème en assurant une autonomie qui peut-être importante avec des coûts relativement faibles, elle introduit non seulement des contraintes de maintenance incompatibles avec certaines applications, mais aussi des problèmes de pollution. La récupération de l'énergie thermique, mécanique, électromagnétique, solaire ou éolienne est une solution très prometteuse. Dans ce cas, la vie de l'objet connecté peut-être prolongée. Cependant, l'énergie récupérée dépend fortement des conditions au voisinage du dispositif et peut donc varier de façon périodique ou aléatoire. Il parait alors important d'adapter le système (mesure et transmission de données) aux contraintes de la récupération d'énergie. L'objectif de la thèse est de proposer une solution de capteur autonome basée sur un système de récupération et de gestion multisources d'énergies (solaire et éolienne) et pouvant-être mis en oeuvre dans différentes classes d'applications IoT. On s'intéresse, dans un premier temps, à la modélisation de la consommation du noeud capteur. Ensuite, on modélise le système de récupération multisources. Puis, on se focalise sur le management de puissance du système autonome. Ce management est basé sur des prédictions de l'énergie disponible et de celle consommée. Enfin, le travail de modélisation et d'optimisation est validé par des expérimentations afin d’avoir un démonstrateur de Capteur Communicant Autonome en Énergie pour les applications IoT. / Researchers aim to develop entirely autonomous sensors. By ensuring an important autonomy, the use of batteries solves part of the energy problem with relatively low costs. However, batteries introduce different problems such as maintenance and environmental pollution. Harvesting thermal, mechanical, electromagnetic, solar or wind energy present in the environment is an attractive solution. Using harvested energy from their surroundings, wireless sensor nodes can significantly increase their typical lifetime. Nevertheless, the harvested energy depends on the surrounding conditions of the device and can vary periodically or randomly. It seems important to adapt the system (measurement and data transmission) to the harvesting energy constraints. The thesis objective is to provide an autonomous sensor solution based on a multisources energy harvesting and management system (solar and wind energies), which can be used in different IoT applications. First, we are interested in modeling and optimizing the sensor node energy consumption. Then, the multiple harvesting system is modeled according to the energy needs of the sensor node. Besides, we focus on the power management of the autonomous system. This management part is based on predictions of both available and consumed energies. Finally, the proposed modeling and optimization studies are validated with experimental works in order to develop an Autonomous Communicating Sensor platform for IoT applications.

The main goal of this thesis is to highlight the various limitations that the LPWAN LoRa and by proxy other similar technologies currently suffers from to give further insight into how these limitations can affect implementations and products using such a network. The thesis will be supported by experiments that test how a LoRa network gets affected by different environmental attributes such as distance, height and surrounding area by measuring the signal strength, signal to noise ratio and any resulting packet loss. The experiments are conducted using a fully deployed LoRa network made up of a gateway and sensor available to the public. To successfully deploy a LoRa network one needs to have concrete information about how to set it up depending on different use cases as battery lifetime and a solid connection has to be kept in mind. We test the various performance aspects of a LoRa network including signal quality and packet loss at different communication ranges. In addition to that we also test different environments and investigate how these can impact the performance. The conclusions made in this thesis are that a LoRa network is limited in its use cases for smaller scale projects with low gateway elevation that still require a large distance. This is due to the obstruction of the signal quickly making it reach unusable levels at roughly 300m in a city and 600m in a forest. Making the line of sight free either by elevation of the hardware or by adapting to the terrain makes the network perform very well making the possibility for packet loss lower which in combination with the low duty cycle of the transmissions is needed as every packet lost is going to be very noticeable.

Farmers run complex operations to fully plant, manage, grow, and harvest crops through the seasons. To help alleviate the tough decision-making process, tools have been created to inform farmers about their machinery and field status. GPS localization and machine state identification provides useful information to farm managers. A tool was created that successfully utilizes GPS data taken from loggers on tractors, combines, and grain trucks to successfully identify the states of all the machines in the field, including, idle, active, on the go, and stationary unloading. Initial results of the algorithm provide a 96% success rate in determining the state of the combine during harvest. Additionally, the algorithm was accurate at determining the state of grain carts and grain trucks at the boundaries of the field 94% of the time. In addition to GPS state identification, LoRa was identified as a potential technology which could link grain trucks and combines in real time providing useful information for in field decision making. Using a mobile end node and stationary gateway, testing was done to evaluate the performance and range of LoRa at long range and speeds ranging from 8 km/h to 96 km/h. Testing revealed a packet reliability of 77% at 8 km/h and a packet reliability of 43% at 96 km/h. A sharp decline in packet reliability was identified around a speed of 16km/h. <br><br>

LoRaWAN is a wireless network technology based on the LoRa modulation technology. When planning such a network, it is important to estimate the network’s coverage, which can be done by calculating path loss. To do this, one can utilize empirical models of radio wave propagation. Previous research has investigated the accuracy of such empirical models for LoRa inside cities. However, as the accuracy of these models is heavily dependent on the exact characteristics of the environment, it is of interest to validate these results. In addition, the effect of base station elevation on the models’ accuracy has yet to be researched. Following the problems stated above, the purpose of this study is to investigate the accuracy of empirical models of radio wave propagation for LoRa in an urban environment. More specifically, we investigate the accuracy of the models and the effect of base station elevation on the models’ accuracy. The latter is the main contribution of this study. To perform these investigations, a quantitative experiment was conducted in the city of Jönköping, Sweden. In the experiment a base station was positioned at elevations of 30, 23, and 15m. The path loss was measured from 20 locations around the base station for each level of elevation. The measured path loss was then compared to predictions from three popular empirical models: the Okumura-Hata model, the COST 231-Walfisch-Ikegami model, and the 3GPP UMa NLOS model. Our analysis showed a clear underestimation of the path loss for all models. We conclude that for an environment and setup similar to ours, models underestimate the path loss by approximately 20dB. They can be improved by adding a constant correction value, resulting in a mean absolute error of at least 3,7-5,6dB. We also conclude that the effect of base station elevation varies greatly between different models. The 3GPP model underestimated the path loss equally for all elevations and could therefore easily be improved by a constant correction value. This resulted in a mean absolute error of approximately 4dB for all elevations.

The thesis "General Security of the Internet of Things" deals with the analysis of networks with low power consumption in the theoretical part -- especially LoRaWAN networks. Further, the thesis deals with the general security of the Internet of things and the security risks of LoRaWAN networks. The practical part is focused on building the LoRaWAN gateway, which is realized with the Raspberry Pi platform with the iC880A-SPI extension module. The gateway is put into operation with full settings, assignment to the network server. Sensors configuration, creation an application, and assign it to the application server. In the practical part, a replay attack on LoRaWAN technology, which demonstrates the vulnerability of this technology, is realized.

This diploma thesis deals with the study and measurement of coexistence scenarios that can occur between the LTE and LoRa systems in the unlicensed ISM band 2.4 GHz. A common radio frequency band in which LTE and LoRa systems can coexist is defined. An appropriate laboratory measurement is proposed and realized, allowing automatized measurement of the defined coexistence scenarios. For this purpose, a personal computer, professional measurement equipment and software MATLAB are utilized. Functionality of the proposed concept is verified by extensive measurements. The obtained results are graphically shown and discussed in detail.

The diploma thesis in theoretical part focuses on LPWAN in general, meaning the low power wireless device falling into IoT category with a focus on LoRaWAN. The second half of the theoretical part focuses on describing localization techniques and principles in general and selection of one suitable technique for implementation in LoRaWAN. The practical part focuses on the proper HW customizations to enable the localization in this network. There are also described all the steps needed to build the whole working LoRaWAN network. The TDoA localization algorithm is described, the functionality is verified by simulation and also by testing under real conditions. In the end, the results are explained, the shortcomings of the technology are described and finally a suggestion for improvement is provided.

This thesis deals with determine location using very low power consumption device. The main target was to design and construct device using right platform and sensors for localization, sending data using IoT LoRa network and than processing data on server's side. To solve the problem, it was used community network TheThingsNetwork. In thesis I created power efficient device, which can find current location using GPS system and deliver it to user using LoRaWAN network.

<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>