LoRaWAN is one of the most adopted low-power wide-area networks, which use theproprietary LoRa modulation developed by Semtech to provide high sensitivity at lowdata rates for long ranges. LoRaWAN providing coverage using single-hop gatewaysto thousands of end-devices (sensors) running on batteries. Each gateway requires aconnection to the internet or a private network (Ethernet, 3G/4G, Wifi) to communicatewith the network server. In obstructed areas, with mountains, foliage, or simplyvast areas, multiple gateways are required to provide coverage for the end-devices.Internet/mobile coverage might be missing in some areas. Which quickly brings upthe cost of internet connection in these areas, unless a solution is developed that routesmessages between the gateways using the existing LoRa radio communication standard.Thus reducing required internet connections while providing coverage. This solutionwas developed and evaluated, with a focus on supporting LoRaWAN deviceswith bidirectional capabilities, following the regional regulations, and providing arouting protocol that minimizes the extra data that comes with routing messages overa network. Experiments of three gateways showed that the solution provides a functioningrouting protocol, with as low as 3 extra bytes for routing. While fast enough toprovide bidirectional communication support for end-devices located farthest awayfrom the gateway with the server connection.

The thesis examines hardware IoT platforms, surveys existing platforms and designs modular IoT platform consisting of printed-circuit boards interconnected with M2.COM standard. LoRaWAN modem is used for wireless data transfer. External sensors are connected to the device using connector mikroBUS and QWIIC. Whole system is tested by counting pulses from selected water flow-meter.

Water is an important parameter for crop growth, and the information about the moisture content in soil at different depths is very useful for farmers to determine the best time to water the soil and to irrigate farmland so as to maximize their yield. This thesis project aims to develop a prototype of a multi-depth moisture sensor probe that is part of a large sensing system used in agriculture. The sensor probe has three sets and is required to last for 6-12 months of usage and to be reproduced at a low cost. The sensor probe consists of three sensor boards, on each of which has two different capacitive based sensors and one analog temperature sensor. The three boards are placed approximately 20 cm from each other in the probe. During this project, the two capacitive based sensors were developed, one with arc-shaped plates operating at a frequency less than 1 MHz, and one with electrodes in the form of annular rings operating at a high frequency, approximately 100 MHz. The moisture content in the soil is calculated based on the measurement of the frequency, which depends on the dielectric constant of the soil. For the implementation of the sensor probe, three printed circuit boards (PCBs) for the sensor boards were designed using Altium Designer and then ordered; an STM32 Nucleo board with low power microcontroller was used and the software was implemented in STM32CubeIDE. The lifetime of the sensor probe was calculated for different duty-cycles. With a duty-cycle of 15 minutes, where the sensor probe is active for 1 minute and in sleep mode for 14 minutes, the lifetime of the sensor probe would only be 16 days. With a duty-cycle of 120 minutes instead, with the sensor probe being active for 1 minute, the lifetime is increased to 130 days (less than4,5 months). Due to challenges with the high frequency capacitive sensor, the multi-depth sensor probe does not fully work, and thus cannot be tested with a large testbed. Further work needs to be conducted on the high frequency capacitive sensor and the communication with the gateway.

The purpose of this thesis rose from tackling a specific project led by Cybercom Group. Water Sense was proposed after municipalities expressed the need to conveniently conduct measurements on water in Swedish lakes, and remotely get access to these data. The varying and infrequent nature of measurements result in an inefficient power consumption when a conventional sensor platform is used. Internet of Things is a relatively new and ever-evolving field for wireless sensor networks, where Low Power Wide-Area Network protocols are utilized to cleverly save power. One of these LPWAN protocols is LoRaWAN, a MAC layer protocol that runs on top of the PHY layer protocol LoRa. The chosen platform hardware for sensor nodes is an Adafruit feather equipped with a LoRa radio module, and the Contiki operative system was to be imported and integrated. Contiki OS is developed for small IoT systems with low-power, while offering networking mechanisms and a range of protocols typically utilized in WSNs. The adaptive and modular nature of Contiki allows for custom pairing of protocols to target a specific topology. LoRaWAN has a number of constraints that are disadvantageous for Water Sense, most prominently being a single-hop protocol. Contiki already supports several platforms with drivers, but the CPU and radio module of the Adafruit feather are not one of them. The goal was to integrate the LoRa PHY hardware with Contiki and have an adaptive platform for Water Sense and other scenarios. Unfortunately not all initial goals were achieved, and the physical layer was not fully integrated with Contiki’s APIs. However, the drivers needed for an operational physical layer were completed and range test could be conducted. Therefore, this thesis details the work done for implementing the physical layer and a study on Contiki’s data link protocols in proposed configurations for Water Sense.

Many large-scale distributed Multi-Agent Systems (MAS) exchange information over low- power communication networks. In such scenarios, agents communicate intermittently with each other, often with limited power and over unlicensed spectrum bands that are susceptible to interference, eavesdropping, and Denial-of-Service (DoS) attacks. In this work, we consider a popular low-power, long-range communication protocol known as LoRa. Despite LoRa's high tolerance for noise and interference, it was found vulnerable to interference from particular chirp-type signals. State-of-the-art signal jamming techniques that exploit this property require the knowledge of two sensitive parameters - Bandwidth (BW) and Spreading Factor (SF). However, such information is available only to authenticated parties on the network and not to an eavesdropping adversary. We expose LoRa's vulnerability to DoS attacks by designing an intelligent jammer that surpasses the need for prior knowledge of these parameters. Exploiting a structural pattern in LoRa signals, we propose a Neural Network (NN) implementation for jointly inferring the two parameters by eavesdropping. Through simulation and experimentation, we analyze the detection vulnerability of LoRa for each combination of these parameters at various Signal to Noise Ratio (SNR) values. This work also presents a Radio Frequency (RF) dataset of LoRa signals, which is used to validate our inference model through experimentation. / Master of Science / When many independent devices (or agents) work together in a large system, they often need to communicate with each other. They do so using low-powered networks and often in an intermittent manner. These networks operate on unlicensed radio frequencies, which are open to interference, unwanted snooping, and 'denial-of-service' attacks that could shut down communication. In our study, we focus on a popular low-power, long-distance communication protocol called LoRa. Despite being designed to handle interference and noise well, related literature revealed that LoRa is vulnerable to a specific type of interference caused by 'chirp' signals. Current techniques to jam these signals and disrupt communication require the knowledge of two important factors - bandwidth and spreading factor. Normally, only authorized parties in the network would know these details, not any outsiders looking to interfere. However, we exploit LoRa's vulnerability without knowing these two parameters. By identifying a pattern in LoRa signals, we designed an artificial intelligence model that can determine these two parameters just by listening in. We then ran simulations and conducted experiments to understand how susceptible LoRa is to being detected under various levels of signal strength and noise. We also prepared a dataset of LoRa signals and used this data to confirm the effectiveness of our model.

Med ett ökande antal IoT enheter finns behov av energieffektiva metoder för överföring av data över långa avstånd. Low Power Wide Area Network (LPWAN) är ett samlingsnamn för nätverkstekniker som utvecklats för att tillgodose dessa behov. LoRa som undersökt i detta arbete är en av dessa tekniker och arbetets syfte har varit att ta reda på hur olika typer av terränger påverkar överföringen med LoRa samt vilka möjligheter det finns för att förbättra överföringen då förhållandena inte är gynnsamma. Undersökningen har genomförts genom tester där nätverksutrusning ställts upp på utvalda platser för att göra mätningar på signalstyrka och paketförlust vid skogs- och stadsmiljö samt fri sikt. Parametrar som inverkar på signalstyrka och paketförlust har varierats vid ett av testen för undersökning vid ej gynnsamma förhållanden. Att kunna på ett lämpligt sätt samla in och presentera data från en IoT-applikation är en förutsättning för att kunna dra nytta av den informationen som applikationen ger. Ett SCADA system används inom många områden till detta ändamål och arbetet innefattar även en lösning för överföring från LoRa till WinCC som är ett SCADA system. Undersökningen av LoRa har visat att längst räckvidd med bäst signalstyrka och minst paketförlust fås vid fri sikt och den terräng som ger sämst resultat är skogsterräng. Den parameter som ger mest påverkan på signalstyrkan är bandbredden och parametern spridningsfaktor ger vid ökning ett mindre antal förlorade datapaket. / With an increasing number of IoT devices, there is a need for energy efficient methods for transferring data over long distances. The Low Power Wide Area Network (LPWAN) is a collective name for network technologies developed to meet these needs. LoRa, which has been investigated in this work, is one of these techniques. The purpose of the investigation has been to find out how different types of terrain affect the transmission with LoRa and what opportunities there are to improve the transmission when the conditions are bad. The investigation has been carried out through tests where network equipment has been placed in selected locations to make measurements on signal strength and packet loss in forest and urban environments as well as free sight. Parameters that give an impact on signal strength and packet loss have been varied in one of the tests for investigation in the case of bad conditions. Being able to collect and present data from an IoT application is a condition to get any benefits form the information from the application. A SCADA is used in many areas for this purpose and the work also includes a solution for transmission of data from LoRa to WinCC which is a SCADA system. The investigation of LoRa has shown that the longest range with the best signal strength and with the minimum number of lost packages are obtained in clear sight and the terrain that produces the worst results is forest terrain. The parameter that has the most impact on signal strength is the bandwidth and the parameter spreading factor gives a smaller number of lost data packets when increasing.

Humans are growing older which presents challenges for the health care system. One solution for allowing individuals to continue living in their home, despite age related dif- ficulties, is a sensor based surveillance system. These systems can monitor a number of parameters, for example motion or temperature. If certain limits are exceeded the sys- tem can notify family members or health care services. The aim of this project was to build a prototype of such a system which also had to be cheap and easy to install and maintain. The final prototype consists of a motion detection sensor in the bathroom, a temperature sensor around the kitchen stove and a temperature sensor for measurement of ambient room temperature. Each sensor is connected to its own Arduino and they are all programmed with different limits. The sensors communicate wirelessly with a central hub through the communication protocol LoRa. Once the central hub, which consists of a Raspberry Pi, receives a LoRa signal it sends an email to a chosen address. / Människor blir allt äldre vilket är en utmaning för sjukvården. En lösning som tillåter individer att fortsätta bo i sina hem, trots åldersrelaterade svårigheter, är ett sensorba- serat övervakningssystem. Sådana system kan övervaka ett flertal parametrar, exemåelvis rörelse eller temperatur. Om vissa gränser överskrids kan systemet underrätta anhöriga eller hemtjänsten. Syftet med det här projektet var att bygga en prototyp av ett sådant system, som även skulle vara billig och enkel att installera och underhålla. Den slutgiltiga prototypen består av en rörelsedetektor i badrummet, en temperatursensor vid köksspisen och en sensor som mäter den omgivande temperaturen i ett rum. Varje sensor är kopp- lad till en egen Arduino och de är alla programmerade med olika gränsvärden. Sensorerna kommunicerar trådlöst med en centralenhet genom kommunikationsprotokollet LoRa. När centralenheten, som består av en Raspberry Pi, tar upp en LoRa-signal skickar den ett email till en vald adress.

Low Power Wide Area Networks (LPWAN) are able to combine long range communication with a low energy consumption sacrificing performance in terms of bit rate and message frequency. This thesis presents a general evaluation of the LPWAN characteristics and a description of the LPWAN protocols LoRaWAN, SigFox and NB-IoT. It also covers a method to evaluate if a LPWAN technology would be a suitable choice of communication technology for a certain use case. Lastly, it covers the implementation of LoRaWAN on a connected electromechanical lock and investigates in the real life performance of the lock by using eight nodes in two case studies involving four locations each. The lock was evaluated from how often it was able to send a heartbeat (a status message), how reliable the communication was, what latency a user could expect and how much energy a data transmission required. Two of the eight nodes were placed in a deep indoor environment. One of them, located 0.794 km from a gateway was able transmit every 150th second. The other one located 1.85 km from a gateway was not able to successfully deliver any packets at all. Five nodes were able to transmit most heartbeats within 10 seconds. The Packet Delivery Ratio (PDR) was below 90% for all locations except for one. In this location, the node was placed close to a large window and managed to communicate with a gateway 3.22 km away with a PDR of 97% and almost exclusively with less than 10 seconds between transmission. The results in this thesis show the potential in LoRaWAN but highlights how dependent the performance will be of the placement of the lock. / Genom att kombinera låg dataöverföringshastighet och låg meddelandefrekvens kan LPWAN uppnå en kommunikation med lång räckvidd och låg energiförbrukning. Denna uppsats går igenom vad som karaktäriserar LPWAN i stort samt presenterar LPWAN-protokollen LoRaWAN, SigFox och NB-IoT. Den visar även en metod vilken kan användas för att utvärdera hur väl ett use case lämpar sig för LPWAN-tekniken. Slutligen görs en implementering av LoRaWAN i ett uppkopplat lås från ASSA ABLOY för att undersöka vilken prestanda som är möjlig att uppnå för åtta olika noder i två olika fallstudier. Låset utvärderades utfirån hur ofta det kunde skicka statusmeddelanden, hur tillförlitlig kommunikationen var samt hur mycket energi som förbrukades. Två av åtta noder placera-des långt in i sina respektive byggnader, den ena kunde endast skicka statusuppdateringar i intervaller om 150 sekunder och den andra lyckades inte leverera några datapaket alls. Fem noder lyckades skicka de flesta statusuppdateringerna i intervall under tio sekunder. Resultatet visade på en packet delivery ratio under 90% i samtliga fall förutom ett. Där placerades noden nära ett stort fönster och lyckades kommunicera med en gateway 3.22 km bort med en PDR på 97% och mindre än 10 sekunder mellan sändningarna. Detta resultat visar potentialen för LoRaWAN men belyser även hur beroende prestandan kommer att vara av hur låset placeras.

In the Internet of things (IoT), many applications will require low-power and low-cost to achieve long lifetime and scale (respectively). These types of applications are referred to as massive IoT, as opposed to critical IoT, which emphasizes ultra-high reliability and availability and low latency. One type of network catering to massive IoT applications are Low-Power Wide Area Networks (LPWANs), and presently, many LPWAN standards are trying to assert their role in the IoT ecosystem. This thesis explores LPWANs from both technical and non-technical perspectives to ascertain their use-case versatility and influence on the future telecommunications’ landscape. With respect to spectrum, the studied LPWANs may be categorized as unlicensed LPWAN or licensed LPWAN. The prior category typically refers to proprietary solutions and in this thesis are represented by SigFox and LoRaWAN. The latter group includes EC-GSM-IoT, eMTC, and NB-IoT and can be considered synonymous with cellular LPWAN because they are designed to be integrated into existing cellular infrastructures. The results indicate that all of the different types of explored LPWANs support applications without strict downlink, payload size, and latency requirements. For use cases without these specific demands (typically sensors, meters, tracking, etc.), it is not a question of whether or not a network fulfills the requirements, but rather how flexible the requirements are. As a result the choice of network will be determined by non-technical aspects and a cost versus functionality trade-off where unlicensed LPWAN is typically cheaper. Hence, both categories of LPWANs offer a unique value proposition; therefore, they can be considered complementary. This notion is reinforced when looking at non-technical aspects such as ecosystem, regulation, network ownership and control, and network coordination, which differ quite significantly. Furthermore, unlicensed LPWANs are likely to be the vanguard of a new type of competitor offering the core service of connectivity. / Inom Internet of Things (IoT) kommer många applikationer att kräva låg effekt och låg kostnad för att uppnå en lång livstid och skala. Dessa typer av applikationer refereras till som massiv IoT, vilket står i motsats till kritisk IoT som kräver ultrahög tillförlitlighet och tillgänglighet och låg fördröjning. En typ av nätverk som ämnar tillgodose kraven av massiv IoT är Low-Power Wide Area Networks (LPWANs), och idag försöker många av dessa hävda sig inom IoT ekosystemet. Detta examensarbete undersöker LPWANs from ett teknisk och icke-tekniskt perspektiv för att utröna deras mångsidighet och påverkan på det framtida telekomlandskapet. Med avseende på spektrum kan de i detta examensarbete undersökta nätverken kategoriseras som olicensierat LPWAN eller licensierat LPWAN. Den tidigare hänvisar typiskt till proprietära lösningar och representeras i detta arbete av SigFox och LoRaWAN. Den senare kategorin består av EC-GSM-IoT, eMTC, och NB-IoT och kan betraktas som synonymt med mobil LPWAN eftersom de designade för att bli integrerade i existerande mobila nätverk. Resultaten indikerar att alla nätverk stödjer applikationer utan strikta krav när det gäller nedlänkens funktionalitet, mängden data per meddelande, och fördröjning. För applikationer utan dessa specifika krav (typiskt sensorer, mätare, spårning, etc.) är det inte en fråga om huruvida ett nätverk uppfyller kraven eller ej, utan snarare hur flexibla kraven är. Därför kommer valet av nätverk att bestämmas av icke-tekniska aspekter och en avvägning mellan kostnad och funktionalitet vari olicensierat LPWAN är vanligtvis billigare. Därmed erbjuder båda kategorier av nätverk en unik värde proposition och kan därför betraktas som komplementerande. Denna föreställning är förstärkt av att nätverken skiljer sig signifikant när det gäller deras icke-tekniska aspekter såsom ekosystem, reglering, ägandeskap och kontroll, och nätverks koordinering. Dessutom är olicensierade LPWANs troligen är förtruppen av en ny typ av konkurrent som erbjuder den grundläggande servicen av konnektivitet.

På Kalmar Länssjukhus har det varit problematiskt att lokalisera rullstolar på sjukhusets område. För att underlätta den dagliga verksamheten kring dessa rullstolar har sensorer uppkopplade till LoRaWAN varit en möjlig lösning. Detta projekt har därför undersökt om LoRaWAN tillsammans med ett positioneringssystem uppfyller kriterierna för att vara en lämplig lösning.  De parametrar som undersökts var noggrannheten för geografisk positionsbestämning av en sensor, signalstyrkan och väntetiden för signalöverföringen. För att mäta de önskade parametrarna användes sensorer kopplade till spårningssystemet Traxmate. Sensorns geografiska position beräknades i Traxmate genom trilateration där MAC – adresser hos närliggande Wi – Fi accesspunkter utnyttjades. Spårningssystemet kunde därmed hämta rådata från sensorerna som därefter sammanställdes i MATLAB. Resultatet visade att LoRaWAN i sig kan vara lämpligt i en sjukhusmiljö. Däremot finns det brister i positioneringssystemet som bör vidareutvecklas för att kunna rekommenderas till ett sjukhus. / Kalmar Länssjukhus has been experiencing difficulties with localization of wheelchairs in the hospital area. In order to facilitate the work of the staff who are searching for the wheelchairs, sensors connected to the LoRaWAN wireless network can be used. Thus, this project has evaluated LoRaWAN together with a positioning system to determine whether the solution is suitable for a hospital environment.  The evaluated parameters where the accuracy of geographical position determination of a sensor, the received signal strength indicator, and the delayed time for the transmission of a signal. Sensors connected to the Traxmate tracking system were used to measure the desired parameters. The sensor’s geographical position was calculated in Traxmate by trilateration where MAC – addresses of nearby Wi – Fi access points were used. The tracking system was thus able to retrieve raw data from the sensors which were then compiled in MATLAB. The results showed that the wireless network structure LoRaWAN satisfied the criteria for usage in a hospital environment. However, the positioning system showed some flaws and thus it should be further investigated in order to be recommended for usage in a hospital environment.