This diploma thesis deals with the design of low-power IoT device communicating by using the NB-IoT standard. The theoretical part of the thesis is dedicated to the explanation of the principles and capabilities of communication in IoT networks Sigfox, LoRa and NB-IoT, and also its physical layer, network architecture, techonology principles and frequency bands used. The application part of the thesis is dedicated to design of the NB-IoT device from the system design through the selection of main components to the detailed physical design of the device. Two prototypes of the device with two different radio modules used are fabricated on which is performed measurement of the power profile of the device in various operation modes.

Nos travaux s’orientent vers les problèmes de réseaux sans fil liés à la coexistence des communications machine-to-machine (M2M) et humain-humain (H2H). On souhaite souligner l'impact mutuel entre les trafics M2M et H2H dans un contexte d’Internet des objets (IoT : Internet Of Things) en particulier lors des catastrophes. Les communications M2M, qui devraient connaître une roissance exponentielle dans un avenir proche, constitueront un facteur important pour affecter tous les réseaux mobiles. On prévoit un grand nombre d'appareils M2M qui entraînera inévitablement des problèmes de saturation et aura des impacts remarquables sur les trafics, les services et les applications M2M et H2H. Pour étudier les influences mutuelles M2M et H2H, nous développons un nouveau modèle markovien à temps continu (CTMC) pour simuler, analyser et mesurer les différentes stratégies d'accès aux réseaux sans fil. Notre modèle nous a permis de contourner certaines limitations des simulateurs professionnels de LTE-A (Long Term Evolution-Advanced) comme SimuLTE en terme d’un nombre massif d'appareils M2M, une flexibilité de certains paramètres ou pour élaborer plus des outils statistiques. Lors d’un sinistre et suite à un énorme nombre de M2M souhaitant accéder aux réseaux sans-fil, nous avons constaté un épuisement rapide de la bande passante allouée dans les réseaux LTE-M (Long Term Evolution for Machines) ou Narrow Band for IoT (NB-IoT). Pour résoudre ce problème, nous proposons une nouvelle approche appelée Adaptive eNodeB (A-eNB) pour les réseaux LTE-M et NB-IoT. Selon nos simulations, l’A-eNB peut résoudre progressivement le problème de surcharge tout en assurant une satisfaisante qualité de service (QoS) pour le trafic H2H. Avec le concept d’A-eNB, un réseau LTE-M pourra adapter ses ressources pour faire face à une augmentation progressive du nombre de connexions M2M accédant au réseau LTE-M / NB-IoT et en même temps réduire l'impact sur le trafic H2H. / This Ph.D. work aims to study the Machine-to-Machine (M2M) congestion overload problem and the mutual impact among M2M and Human-to-Human (H2H) traffics in IoT (Internet of Things) environments specifically during disaster events. M2M devices with their expected exponential booming in the near future, will be one of the significant factors to influence all mobile networks. Inevitably, the expected huge number of M2M devices causes saturation problems, and leads to remarkable impacts on both M2M and H2H traffics, services and applications. To study the M2M and H2H mutual influences, we create a new platform model based on Continuous-Time Markov Chain (CTMC) to simulate, analyze and measure radio access strategies due to the limitations of existing Long Term Evolution-Advanced (LTE-A) simulators (i.e, SimuLTE) in term of massive M2M devices, parameter flexibility and statistical tools. Additionally, during disaster events, a fast bandwidth depletion of the limited bandwidth assigned to M2M devices in Long Term Evolution for Machines (LTE-M) and Narrow Band for IoT (NB-IoT) networks is expected due to the high arrival request of M2M device network access. To address this problem, we propose a new approach named Adaptive eNodeB (A-eNB) for both LTE-M and NB-IoT networks. The A-eNB can solve gradually the overload problem, while keeping the H2H traffic Quality of Service (QoS) not to be affected badly. The network adaptation is provided through a dynamic LTE-M resource reservation aiming to increase the number of M2M connections accessing the LTE-M/NB-IoT network and to decrease the impact on H2H traffic.

The newly defined NB-IoT standard currently lacks a toolkit and simulator. In order to develop algorithms for this new standard there is a need for channels and signals as reference during tests. MATLAB is commonly used for testing LTE signals and therefore the toolkit was developed in this environment. The toolkit focuses primarily on the Layer 1-relevant functionality of NB-IoT, the grid generation, encoding, rate-matching and modulation of channels. The simulator focuses on testing the developed toolkit in a virtual LTE NB-IoT environment. The virtual environment attempts to emulate a base station and a terminal. The path followed is scheduling, channel processing, grid generation, QPSK and OFDM modulation through a modeled channel, OFDM demodulation, channel estimation, equalisation, QPSK demodulation and reversal of channel processing. The simulator tests primarily the NPDSCH channel implementations. Measurements of bit error and block error rates were made and it was concluded that they follow the expected trends. More testing is required to validate the remaining channels. A sector equaliser and an interpolating equaliser were tested by measuring block error rate and checking constellation diagrams and it was concluded that the performance of the interpolation equaliser is more consistent. In order to improve the equalisation further the noise estimation must be reworked.

This report is an exposition of the development of a measuring instrument whosetask is to map the physical coverage of the NB-IoT network. The measuringinstrument was developed on TietoEvry's initiative, as it was in their interest to obtaina measuring instrument that can be used to map the coverage in parts of VarmlandsNB-IoT network. Which in this way provides an assessment for any future projectsinvolving NB-IoT. The development of the measuring instruments you can carry withyou out into the field, uses a microcomputer for collecting measurement data savedin a log file using Python. The report also describes a complimentary program that inturn takes and visualizes the acquired data in the form of markers on a map, whichshows the signal strength of the NB-IoT network. The visualization program is writtenin Java and is based on the open source project: jxmapviewer2. However, themeasuring instrument as it is today needs further testing to ensure the accuracy ofthe measuring instrument. Something that can be looked over in the future.

This Master thesis is focused on the design and consequential realization of the Multi-RAT communication device. The theoretical part describes a comparison of two promising communication LPWA (Low Power Wide Area) technologies that are available to use in the Czech Republic. These technologies are NB-IoT (NarrowBand-Internet of Things) and LoRaWAN (Long Range Wide Area Network). The practical part contains a description used components, their consequential fitting and testing of designed printed circuit board of the device. The thesis also describes the implementation of software and realized measurement. Technical documentation of a device can be found in the appendix of this thesis.

With technology advancements and the prices of electronic components reducing over the last fifteen years, many devices and systems that would have been proprietary only for large companies or industry giants are becoming an everyday household item. Various areas of technology have been benefiting from this but one of the biggest is the Internet of Things (IoT).With the prevalence of IoT, it has been integrated into houses, small businesses, farms, agriculture, building automation, etc. and the user population is now a resource to the industry as they complete personal projects. Within any project there are always limitations, this might be a limited time, limited funds, limited distance, or limitations of the devices being used. This study proposes to evaluate two low-powered networks, Narrowband Internet of Things (NB-IoT)and Long-Range Wide-Area Network(LoRaWAN), in different environments with the goal of understanding where the signal propagation is better and what distances can be reached despite obstructions. Distances and signal propagations, when measured by the manufacturers are often evaluated in ideal conditions which is rarely the case when utilized in the field. This creates a gap in the deployment and the end-users are frequently faced with diminished performances. As IoT is predominantly employed in urban and rural areas this study will focus on those two settings by testing the Received Signal Strength Indicator (RSSI)at various distances. The evaluation testing of the two systems showed each system performing more consistently in rural areas but neither had 100% coverage at any locations.

The United States Federal Communications Commission (FCC) in its recent report and order has prescribed the creation of Citizens Broadband Radio Service (CRBS) in the 3.5 GHz band to enable sharing between wireless broadband devices and incumbent radar systems. This sharing will be enabled by use of geolocation database with supporting infrastructure termed as Spectrum Access System (SAS). Although using SAS for spectrum sharing has many pragmatic advantages, it also raises potentially serious operational security (OPSEC) issues. In this thesis, we explore OPSEC, location privacy in particular, of incumbent radars in the 3.5 GHz band. First, we show that adversarial secondary users can easily infer the locations of incumbent radars by making seemingly innocuous queries to the database. Then, we propose several obfuscation techniques that can be implemented by the SAS for countering such inference attacks. We also investigate obfuscation techniques' efficacy in minimizing spectral efficiency loss while preserving incumbent privacy. Recently, the 3GPP Rel.13 has specified a new standard to provide wide-area connectivity for IoT, termed as Narrowband IoT (NB-IoT). NB-IoT achieves excellent coexistence with legacy mobile standards, and can be deployed in any of the 2G/3G/4G spectrum (450 MHz to 3.5 GHz). Recent industry efforts show deployment of IoT networks in unlicensed spectrum, including shared bands (e.g., 3.5 GHz band). However, operating NB-IoT systems in the 3.5 GHz band can result in significant BLER and coverage loss. In this thesis, we analyse results from extensive experimental studies on the coexistence of NB-IoT and radar systems, and demonstrate the coverage loss of NB-IoT in shared spectrum. / Master of Science / Spectrum sharing has been viewed by spectrum regulators and industry stakeholders as the most viable solution to overcome the spectrum congestion and to enable next generation wireless networks. Towards this end, the Federal Communications Commission in the United States has prescribed rules to enable sharing between incumbent radars and broadband wireless networks in the 3.5 GHz band. This sharing however will be enabled geolocation databases and supporting infrastructure known as Spectrum Access System, which are prone to privacy attacks by malicious secondary users. Preserving privacy of incumbent systems is vital as they are mostly military radars. In this thesis, we demonstrate such attacks and later propose efficient techniques to preserve the privacy of the incumbent systems while enabling better spectrum utilization. The phenomenal growth in smarter end-user devices and machine-to-machine (M2M) connections is a clear indicator of the growth of Internet of Things (IoT), and growing importance of wide area IoT networks. Recently, the telecommunications standard development body, 3GPP, has defined Narrowband IoT (NB-IoT) optimized for IoT. Also, NB-IoT has many features common to LTE, and it is likely that NB-IoT will also be deployed in bands where LTE will be deployed, including shared bands (e.g., 3.5 GHz band). However, NB-IoT systems that operate in the 3.5 can be prone to harmful radar interference and directly impact coverage of the NB-IoT basestation. In this thesis, we analyse results from extensive experimental studies on the coexistence of NB-IoT and radar systems. We believe this study can be leveraged by future studies to mititage the impact of radar on IoT networks.

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.

Some individuals and older adults have trouble remembering when to take their medication. A medication dispenser machine is one suggested solution to this problem. The purpose of this thesis is to design a prototype of a wireless machine for storing and releasing patients’ medication dosages at a certain time. The user can insert the medication schedule through a platform connected to the machine via wireless technology. In order to achieve the purpose, a literature study was conducted to gather and analyze information about wireless communication technologies to determine the most appropriate wireless technology for the thesis end device. The Arduino MKR NB 1500 is the core component of the prototype of the wireless system. Several types of tests were conducted on the system to evaluate its performance, as well as to determine NB-IoT coverage in real-world scenarios. The NB-IoT technology was proven to be the more suitable technology for the wireless pill dispensing machine and for other IoT applications. Moreover, the system performed satisfactorily in solving the defined problem. Despite this, the system could be improved in terms of design, mechanisms, and hygiene system of medicines. / Vissa människor eller äldre vuxna har svårighet att komma ihåg att ta sin medicin och hantera dem själva. En medicindispenser maskin är den föreslagna lösningen för detta problem. Syftet med detta examensarbete är att designa en prototyp av en trådlös maskin för att lagra och frigöra patienternas läkemedelsdoser vid en viss tidpunkt. Användaren kan infoga medicinschemat via en plattform ansluten till maskinen med hjälp av en lämplig trådlös teknik. För att uppnå syftet genomfördes en litteraturstudie för att samla in och analysera information om trådlös kommunikationsteknik för att bestämma den mest lämpliga trådlösa tekniken för arbetets slut enhet. Arduino MKR NB 1500 är kärnkomponenten i prototypen av det trådlösa systemet. Flera typer av tester utfördes på systemet för att utvärdera dess prestanda, samt för att fastställa NB-IoT-täckning i verkliga scenarier. NB-IoT tekniken har visat sig vara den mer lämpliga tekniken för den trådlösa medicindispenser maskinen och för andra IoT-applikationer. Dessutom fungerade systemet tillfredsställande för att lösa det definierade problemet. Trots detta skulle systemet kunna förbättras när det gäller design, mekanismer och hygiensystem för läkemedel.

abstract: With the new age Internet of Things (IoT) revolution, there is a need to connect a wide range of devices with varying throughput and performance requirements. In this thesis, a wireless system is proposed which is targeted towards very low power, delay insensitive IoT applications with low throughput requirements. The low cost receivers for such devices will have very low complexity, consume very less power and hence will run for several years. Long Term Evolution (LTE) is a standard developed and administered by 3rd Generation Partnership Project (3GPP) for high speed wireless communications for mobile devices. As a part of Release 13, another standard called narrowband IoT (NB-IoT) was introduced by 3GPP to serve the needs of IoT applications with low throughput requirements. Working along similar lines, this thesis proposes yet another LTE based solution called very narrowband IoT (VNB-IoT), which further reduces the complexity and power consumption of the user equipment (UE) while maintaining the base station (BS) architecture as defined in NB-IoT. In the downlink operation, the transmitter of the proposed system uses the NB-IoT resource block with each subcarrier modulated with data symbols intended for a different user. On the receiver side, each UE locks to a particular subcarrier frequency instead of the entire resource block and operates as a single carrier receiver. On the uplink, the system uses a single-tone transmission as specified in the NB-IoT standard. Performance of the proposed system is analyzed in an additive white Gaussian noise (AWGN) channel followed by an analysis of the inter carrier interference (ICI). Relationship between the overall filter bandwidth and ICI is established towards the end. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2017