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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Analýza řídicích procedur v mobilních sítích čtvrté generace / Analysis of control procedures in 4th generation mobile networks

Schaller, Lukáš January 2018 (has links)
The subject of the diploma thesis are procedures in EPS network related to the operation of mobile terminals. In the introduction of my work I described the EPS system, including the quality of services and bearers. The following section focuses on control procedures in the EPS system such as attach network procedure, detach procedure, service request, handover or tracking area procedure. Further, three technologies for Internet of Things were described, namely EC-GSM-IoT, LTE-M and NB-IoT. All the procedures mentioned above were also captured in the experimental VUT EPS network and analyzed by TravelHawk using software M5 and Wireshark. Theoretical and practical findings were subsequently used out for setting of laboratory task for subject MKPM.
12

Implementace a vyhodnocení komunikační technologie LoRaWAN v simulačním prostředí NS-3 / Implementation of the LoRaWAN Communication Technology Using the Network Simulator 3

Mašek, Petr January 2021 (has links)
The diploma thesis focuses on the description of LPWAN (Low Power Wide Area Network) technologies for use in IoT (Internet of Things) communication scenarios. The theoretical part compares communication technologies operating in the license-exempt frequency band, i.e. Sigfox and LoRaWAN (Long Range Wide Area Network). Furthermore, technologies using the licensed frequency spectrum are discussed, specifically, attention is focused on NB-IoT (Narrow Band IoT). Emphasis is placed on LoRaWAN technology and the properties of the unlicensed frequency band below the 1 GHz, which is utilized by this technology. The practical part of the thesis consists of the evaluation of simulation scenarios using an integrated module in the simulation environment NS-3 (Network Simulator 3). Attention is focused mainly on the analysis of data transmission success using selected communication parameters of LoRaWAN technology. The obtained simulation outputs with a focus on mMTC (massive Machine-Type Communication) communication scenarios confirm the relationship between the number of end devices and gateways, communication distance and transmission reliability, or the limit value for the duty cycle.
13

Improving the Energy Efficiency of Cellular IoT Device

Abbas, Muhammad Tahir January 2023 (has links)
Cellular Internet of Things (CIoT) has emerged as a promising technology to support applications that generate infrequent data. One requirement on these applications, often battery-powered devices, is low energy consumption to enable extended battery life. Narrowband IoT (NB-IoT) is a promising technology for IoT due to its low power consumption, which is essential for devices that need to run on battery power for extended periods. However, the current battery life of NB-IoT devices is only a few years, which is insufficient for many applications. This thesis investigates the impact of energy-saving mechanisms standardized by 3GPP on battery life of NB-IoT devices. The main research objective is to classify and analyze existing energy-saving solutions for CIoT and examine their limitations, to study the impact of standardized energy-saving mechanisms on the battery life of NB-IoT devices, both in isolation and combined, and to provide guidelines on how to configure NB-IoT devices to reduce energy consumption efficiently. The research aims to provide a deeper understanding of the effect of energy-saving mechanisms and best practices to balance energy efficiency and performance of NB-IoT devices. Applying the proposed solutions makes it possible to achieve a battery life of 10~years or more for CIoT devices.
14

Smart City Lighting in the City of Stockholm

Pascual Pelayo, Ignacio Javier January 2018 (has links)
The vision of the Smart City and Internet of Things is gradually becoming areality. Many cities around the world have initiated a modernization processtowards more intelligent and ecient management systems and Stockholm isnot an exception. This work is chiey devoted to public lighting; owing toits ubiquitous nature, it may certainly play a major role driving this transformation.It addresses the main concerns of the Trac Oce, in charge of thisinstallation, in relation with the architecture, underlying protocols, opportunities,and available systems in the market, among others.The lack of a unied standard as well as legal, human and security issueshave initially hampered the maturing process of this new paradigm. The existenceof multiple alternatives leads to the overchoice phenomenon and oftendiscourages industries and governments to adopt IoT solutions. Therefore, anextensive survey has been conducted to analyze the suitability of dierent protocolswith the requirements of the installation. Solutions have been classiedin three main categories, and one instance of each, namely IEEE 802.15.4,NB-IoT and LoRa, have been evaluated to illustrate an example architectureand calculate capacity and cost metrics.The demands of such deployment have been identied by agreeing on a basicset of services. As a result, two scenarios (worst-case and optimistic) havebeen proposed to model system's trac. A mathematical methodology hasbeen used to establish a soft limit on the maximum amount of devices servedby a single gateway that should be considered by implementers. In case of NBIoT,the capacity depends entirely upon the network operator, consequentlythe comparative is based on a third model (minimum trac) focused on reducingthe operation cost. In this way, this thesis provides the Trac Ocewith an initial approach to the matter and an unbiased reference frameworkto decide the future development of street lighting in Stockholm. / La vision de la Ciudad Inteligente y el Internet de las Cosas esta cada vezmas cerca de convertirse en una realidad. Una gran cantidad de municipiospor todo el mundo han comenzado un proceso de modernizacion hacia sistemasde gestion mas ecientes y ecaces y Estocolmo no es una excepcion.Este trabajo esta principalmente dedicado al area de la iluminacion publica,puesto que su presencia ubicua la convierten en uno de los entes principalesque impulsan esta transformacion. Mas concretamente, responde a las dudasdel departamento de Traco de la ciudad sobre la posible infraestructura,protocolos de comunicacion, oportunidades y disponibilidad de sistemas en elmercado, entre otros asuntos.La falta de un estandar unicado junto con la aparicion de diferentes cuestioneslegales y problemas de seguridad ha dicultado la maduracion de estenuevo paradigma de comunicaciones. De la misma manera, la existencia demultiples alternativas en el mercado ha generado cierta reticencia del sectorgubernamental e industrial debido a la indecision provocada por el exceso deoferta. Por este motivo, se ha realizado un estudio cualitativo sobre la idoneidadde las diferentes soluciones para los requerimientos que imponen este tipode instalaciones. Se han identicado tres principales categoras y se ha analizadoel protocolo mas representativo de cada una de ellas para ejemplicarla arquitectura del sistema y obtener medidas orientativas sobre su coste ycapacidad.Una vez identicados los servicios basicos que deberan proporcionarse, se hanplanteado dos escenarios que modelan el traco en la red para una situaciondesfavorable y otra optimista. A traves de un desarrollo matematico se haobtenido la cantidad maxima de dispositivos que pueden conectarse a unmismo Gateway para cada tecnologa, con el n de proporcionar un datoorientativo para la entidad encargada del dise~no del sistema. En el caso detecnologas celulares, la infraestructura depende por completo del operador,por lo que se ha determinado mas provechoso estudiar el coste de operacioncon un tercer modelo orientado a la reduccion del mismo. De esta forma,este trabajo provee al departamento de Traco de un primer acercamiento alproblema y un marco de referencia para tomar con coherencia futuras decisionessobre la modernizacion del servicio de alumbrado publico en Estocolmo. / Visionen om den Smarta Staden och Internet of Things blir gradvis en realitet. Många städer runt om i världen har startat en moderniseringsprocess mot intelligenta och mer effektiva system och Stockholm är inget undantag. Den här avhandlingen är främst ägnad åt offentlig belysning eftersom den säkert kan spela en viktig roll för att driva på omvandlingen, på grund av sin allestädes närvarande natur. Den behandlar trafikkontorets, myndigheten som ansvarar för belysningen, största bekymmer i samband med bland annat arkitektur, underliggande protokoll, möjliga och tillgängliga system på marknaden. Bristen på en enhetlig standard och juridiska, mänskliga samt säkerhetsfrågor har inledningsvis hindrat mognadsprocessen för detta nya paradigm. Förekomsten av flera alternativ leder till övervalsfenomen och avskräcker ofta industrier och regeringar för att anta IoT-lösningar. Därför har en omfattande undersökning genomförts för att analysera lämpligheten för olika protokoll med krav för installationen. Lösningar har klassificerats i tre huvudkategorier, och ett exempel av var, nämligen IEEE 802.15.4, NB-IoT och LoRa, har utvärderats för att illustrera en exempelarkitektur och beräkna kapacitets- och konstandsmått. Kraven på sådan utplacering har identifierats genom att komma överens om en grundläggande uppsättning tjänster. Två scenarier (värsta fall och optimistisk) har föreslagits för att påvisa systemets trafik. En matematisk metod har använts för att fastställa en mjukgräns för de maximala mängder anordningar som betjänas av en enda gateway vilken bör övervägas av implementatörer. NB-IoT kapaciteten beror på nätoperatören, därför grundas jämförandet med en tredje modell (minsta trafik) fokuserad på att minska driftskostnaden. Det här examensarbetet tillför sålunda trafikkontoret ett första tillvägagångssätt och en saklig referensram för att bestämma den framtida utvecklingen av gatubelysningen i Stockholm.
15

Designing Applications for use of NB-IoT

Tengvall, John, Wildmark, Dennis January 2017 (has links)
IoT är en marknad som har växt fort under de senaste åren och skapat sig en egen industri. Kärnan i IoT är internetanslutningen och i många fall är mobil kommunikation den bästa lösningen för en IoT-produkt. Problemet är att det inte finns något självklart val av mobil kommunikation för användning i en IoT-produkt. Den mobila kommunikationsbranschen har reagerat på det nya behovet av mobil kommunikationsstandard för IoT och 2016 släppte 3GPP en ny standard av typen LPWAN kallad NB-IoT. Flera företag verkar för att implementera denna standard, och det finns ett behov av att undersöka hur applikationer kan utnyttja standarden på ett effektivt sätt. Denna uppsats presenterar en jämförelse mellan två applikationer som använder olika ALP, HTTP och CoAP, i en LPWAN-kontext. Resultaten av denna jämförelse visar att det finns mycket att vinna på att välja CoAP istället för HTTP, speciellt i en IoT-miljö som applikationerna presenterade i denna uppsats. Uppsatsen presenterar även en samling egenskaper som en applikation bör ha för att utnyttja en LPWAN-kommunikationsstandard effektivt. / The Internet of Things (IoT) is a market that has grown very fast in the last few years,creating an industry of its own. The core of IoT is the Internet connectivity and many times, the best solution for an IoT device is to use some form of mobile connection to solve this. The problem is that there is no obvious choice of mobile communication standard for use in an IoT device. The mobile communications industry has reacted to this newly emerged need of amobile communications standard designed for the IoT domain and in 2016 the 3rd Generation Partnership Project (3GPP) released a Low-Power Wide-Area Network (LPWAN) type of standard named Narrowband IoT (NB-IoT). Several companies are working on implementing this standard, and there is a need to investigate how applications can utilize the standard effectively. This thesis presents a comparison between two applications using different ApplicationLayer Protocol (ALP)s, Hyper-Text Transfer Protocol (HTTP) and Constrained Application Protocol (CoAP), in an LPWAN context. The results of this comparison shows that there is a lot to gain by choosing CoAP over HTTP, especially in an IoT environment such as the applications presented in this thesis. The thesis also presents a collection of properties that applications should have to use an LPWAN effectively.
16

Système M2M/IoT par satellite pour l'hybridation d'un réseau NB-IoT via une constellation LEO / M2M/IoT satellite system for the hybridization of a NB-IoT network via a LEO constellation

Cluzel, Sylvain 07 March 2019 (has links)
Le but de cette thèse est d'étudier la mise en œuvre de services de type Internet of Thing (IoT) ou Machine to Machine (M2M) par satellite. Ce type de système pose une double problématique: d'une part au niveau couche physique : les contraintes liées au terminal (limité en puissance, énergie, taille d'antenne), au canal (potentiellement avec masquage et multitrajet) et au segment spatial impliquent la mise en œuvre de différentes techniques (entrelacement, suppression d'interférents, ...) permettant d'assurer le bilan de liaison adéquat pour le service. D'autre part, le besoin d'offrir un accès à la ressource à un grand nombre de terminaux demandant un débit faible implique l'utilisation de techniques d'accès à contention optimisées, ainsi que la prise en compte au niveau accès des problématiques d'économie d'énergie. Cette couche accès doit également être en mesure de s'interfacer avec des architectures réseaux plus vastes. On peut citer par exemple les architectures Internet afin de supporter des services IP pour l'IoT, avec des notions de services intermittents, telles qu'on les retrouve dans les réseaux DTN, ou bien les architectures 4G/5G pour la mise en œuvre de services mobiles. Cette thèse va investiguer deux approches systèmes innovantes ainsi que différentes techniques aussi bien couche physique que couche accès (potentiellement couplée) permettant leur mise en œuvre. Le premier scénario système consiste à l'utilisation d'un terminal satellite relais très bas débit (contrairement au cas classique traité dans la littérature reposant sur des terminaux broadband), s'interfaçant avec des capteurs en technologie accès terrestres. Des techniques innovantes de gestion des ressources et d'économie d'énergie au travers d'une couche accès dédiée (non DVB) pourraient permettre de supporter le nombre très important de terminaux dans ce type de système. Le second scénario repose sur une communication directe avec des capteurs/objets via une constellation satellite. Cette approche pose le problème de l'efficacité de la forme d'onde pour des services extrêmement sporadique et de la fiabilisation de la communication. Il existe de nombreux travaux coté DLR sur ce type de forme d'onde avec notamment la définition de S-MIM. Néanmoins, cette solution semble complexe et de nombreuses optimisations pourraient être apportées. Coté accès, E-SSA (communication asynchrone à spectre étalé avec SIC) défini par l'ESA est également une piste de travail intéressante même si sa mise en œuvre au niveau système et sa complexité doivent être consolidées. / The aim of this thesis is to study the implementation of Internet-based services of Thing (IoT) and Machine to Machine (M2M) through a satellite link. This type of system have to deal with two issues: first the physical layer level: terminal related constraints (limited in power, energy, and antenna size), channel (potentially with masking and multipath) and the space segment involve the implementation of different techniques (interleaving, interference cancellation,) to ensure proper link budget allowing the communication. On the other hand , the need to provide access to the resource to a large number of terminals requiring low throughput involves the use of optimized contention access techniques , as well as taking into account the level of access issues energy saving. The access layer should also be able to interface with larger networks architectures. Internet architectures for example include supporting IP services for Iota, with sporadic services, such as the ones found in the DTN networks, or 4G architectures / 5G for the implementation of mobile services. This thesis will investigate two innovative approaches and different techniques as well as physical layer access layer (potentially coupled) to their implementation. The first scenario involves the use of a very low throughput satellite relay terminal (unlike in the conventional case found in the literature based on broadband terminals), interfacing with terrestrial access technology sensors. Innovative resource management and energy saving techniques through a dedicated access layer (not DVB) could absorb the large number of terminals in this type of architecture. The second scenario is based on direct communication with sensors / objects via satellite constellation. This approach raises the question of the efficiency of the waveform for extremely sporadic services and the reliability of communication. DLR works on this type of waveform including the definition of S -MIM. However, this solution seems to be complex and many optimizations can be made. From the access layer point of view, E -SSA (asynchronous spread spectrum communication with SIC) defined by the ESA is also interesting even if its implementation to the system and its complexity level should be consolidated.
17

Étude et conception de métamatériaux accordables pour la miniaturisation d’antennes aux fréquences micro-ondes / Study and design of tunable metamaterials for antenna miniaturization at microwave frequencies

Kristou, Nebil 08 June 2018 (has links)
Les antennes présentes dans la plupart des systèmes communicants comme les véhicules automobiles, les avions et les trains se multiplient et sont soumises à une contrainte d’intégration de plus en plus sévère. De nombreuses techniques de miniaturisation d’antennes existent et passent toutes par un compromis entre la taille et les performances (bande passante et/ou rendement de rayonnement). Pour les systèmes cités ci-dessus, les antennes sont souvent placées devant ou à proximité d’un réflecteur métallique (toit de véhicule, carlingue d’aéronef). Dans ce cas, l’épaisseur de système antennaire est une contrainte majeure et les métamatériaux de type Conducteur Magnétique Artificiel (CMA) ouvrent des perspectives intéressantes grâce à leurs propriétés électromagnétiques non conventionnelles. Cependant, pour les applications sub-GHz (RFID, LTE, PMR…), les CMA sont limités par les dimensions des cellules unitaires nécessaires à leur mise en œuvre (λg/4) ainsi que leur bande réduite de fonctionnement. Réduire leurs dimensions permet de rendre leur utilisation compatible avec le contexte des antennes miniatures intégrées. Ajouter l’agilité fréquentielle permet de palier le problème de la bande passante réduite dans le cas des antennes et des CMA miniaturisés en ajustant le fonctionnement du système antennaire sur une large bande passante. Cette thèse de doctorat propose d’étudier et de développer un nouveau système antennaire à faible profil composé d’une antenne miniature associée à une métasurface compacte reconfigurable en fréquence et compatible avec le standard NB-IoT dans la bande basse LTE (700 MHz – 960 MHz). / Antennas are now very integrated in several connected systems like cars, airplanes and trains. Many antenna miniaturization techniques exist and all go through a compromise between size and performance (bandwidth and/or radiation efficiency). For the systems mentioned above, the antennas are often placed near a metallic reflector (vehicle roof, aircraft cabin). Within this context, Artificial Magnetic Conductors (AMC) present an attractive reflector for low profile antennas which can take advantage of intrinsic zero reflection phase response to boost antenna performance without the need for thick quarter wave backplane. However, for sub-GHz applications (RFID, LTE, PMR ...), AMC are limited by the size of the unit cells necessary for their implementation (λg/4) as well as their reduced operating bandwidth. AMC miniaturization makes their use compatible with small antennas. Adding tunability restores the possibility of adjusting the operating frequency over a large bandwidth. This PhD thesis proposes to study and develop a new electrically small, low-profile antenna based on miniaturized and tunable AMC for the NB-IoT standard in low LTE band (700 MHz – 960 MHz).
18

Zařízení pro monitorování kvality elektrické sítě / Quality Monitoring Device for Electrical Power Networks

Bartoň, Jan January 2020 (has links)
The diploma thesis deals with the parameters of electricity quality. The aim of this work is to design and implement a prototype device that will allow remote measurement of power quality. The proposed system uses NB-IoT technology for data transmission. The system enables remote measurement of important parameters of electrical energy, such as the magnitude of the supply voltage or the frequency of the electric network. The device can measure electric current, average voltage values and detect dip / swell voltage events. The device reads a sampled electrical signal suitable for harmonic analysis. The device has started to meet the requirements for measuring device of class S according to EN 61000-3-40.
19

Unlicensed and licensed low-power wide area networks : Exploring the candidates for massive IoT

Sjöström, Daniel January 2017 (has links)
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.
20

Design of Cellular and GNSS Antenna for IoT Edge Device

Broumas, Ioannis January 2019 (has links)
Antennas are one of the most sensitive elements in any wireless communication equipment. Designing small-profile, multiband and wideband internal antennas with a simple structure has become a necessary challenge. In this thesis, two planar antennas are designed, simulated and implemented on an effort to cover the LTE-M1 and NB-IoT radio frequencies. The cellular antenna is designed to receive and transmit data over the eight-band LTE700/GSM/UMTS, and the GNSS antenna is designed to receive signal from the global positioning system and global navigation systems, GPS (USA) and GLONASS. The antennas are suitable for direct print on the system circuit board of a device. Related theory and research work are discussed and referenced, providing a strong configuration for future use. Recommendations and suggestions on future work are also discussed. The proposed antenna system is more than promising and with further adjustments and refinement can lead to a fully working solution.

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