Gotowa bibliografia na temat „NB-IoT NETWORKS”

Narrowband-IoT (NB-IoT) is part of a novel group of access technologies referred to as Low-Power Wide Area Networks (LPWANs), which provide energy-efficient and long-range network access to IoT devices. Although NB-IoT Release 13 has been deployed by Mobile Network Operators (MNO), detailed Quality of Service (QoS) evaluations in public networks are still rare. In this paper, systematic physical layer measurements are conducted, and the application layer performance is verified. Special consideration is given to the influence of the radio parameters on the application layer QoS. Additionally, NB-IoT is discussed in the context of typical smart metering use cases. The results indicate that NB-IoT meets most theoretical Third Generation Partnership Project (3GPP) design goals in a commercial deployment. NB-IoT provides a wide coverage by using signal repetitions, which improve the receiver sensitivity, but simultaneously increase the system latency. The maximum data rates are consistent over a wide range of coverage situations. Overall, NB-IoT is a reliable and flexible LPWAN technology for sensor applications even under challenging radio conditions. Four smart metering transmission categories are analyzed, and NB-IoT is verified to be appropriate for applications that are not latency sensitive.

Recently, Internet of Things (IoT) deployments have shown their potential for aiding the realisation of the Sustainable Development Goals (SDGs). Concerns regarding how the IoT can specifically drive SDGs 6, 11 and 9 in developing countries have been raised with respect to the challenges of deploying licensed and unlicensed low-power wide area network (LPWAN) IoT technologies and their opportunities for IoT consumers and service providers. With IoT infrastructure and protocols being ubiquitous and each being proposed for different SDGs, we review and compare the various performance characteristics of LoRaWAN and NB-IoT networks. From the performance analysis of our networks, NB-IoT, one of the standardised promising cellular IoT solutions for developing countries, is more expensive and less energy-efficient than LoRaWAN. Utilising the same user equipment (UE), NB-IoT consumed an excess of 2 mAh of power for joining the network and 1.7 mAh more for a 44-byte uplink message compared to LoRaWAN. However, NB-IoT has the advantage of reliably and securely delivering higher network connection capacity in IoT use cases, leveraging existing cellular infrastructure. With a maximum throughput of 264 bps at 837 ms measured latency, NB-IoT outperformed LoRaWAN and proved robust for machine-type communications. These findings will help IoT consumers and service providers understand the performance differences and deployment challenges of NB-IoT and LoRaWAN and establish new research directions to tackle IoT issues in developing countries. With Nigeria as a case study, for consumers and organisations at a crossroads in their long-term deployment decisions, the proposed LPWAN integrated architecture is an example of the deployment opportunities for consumer and industrial IoT applications in developing countries.

Since the birth of narrowband Internet of Things (NB-IoT), the Internet of Things (IoT) industry has made a considerable progress in the application for smart cities, smart manufacturing, and healthcare. Therefore, the number of UEs is increasing exponentially, which brings considerable pressure to the efficient resource allocation for the bandwidth and power constrained NB-IoT networks. In view of the conventional algorithms that cannot dynamically adjust resource allocation, resulting in a low resource utilization and prone to resource fragmentation, this paper proposes a double deep Q-network (DDQN)-based NB-IoT dynamic resource allocation algorithm. It first builds an NB-IoT environment model based on the real environment. Then, the DDQN algorithm interacts with the NB-IoT environment model to learn and optimize resource allocation strategies until it converges to the optimum. Finally, the simulation results show that the DDQN-based NB-IoT dynamic resource allocation algorithm is better than the traditional algorithm in the resource utilization, average transmission rate, and UE average queuing time.

Low Power Wide Area Networks (LPWANs) play crucial roles in the implementation of low-power and low-cost wide area distributed systems. Currently, two enabling technologies are the main competitors within the connectivity field for the Internet of Things (IoT), primarily because of their scalability, wide range and low power features: Long Range Wide Area Network (LoRaWAN) and Narrowband IoT (NB-IoT). In this paper, a brand new network architecture is presented, which combines both aforementioned technologies. Such a network accounts for sensor nodes, multi-protocol gateways, an a cloud infrastructure. Sensor nodes may be alternatively provided with LoRaWAN or NB-IoT. Multi-protocol gateways can receive and demodulate LoRaWAN packets and upload them to the cloud via the Message Queue Telemetry Transport (MQTT) protocol over NB-IoT. The cloud is transparent with respect to the transmission technology, meaning that data are acquired and stored regardless of the exploited technique (i.e., LoRaWAN or NB-IoT). Indeed, sensor nodes using NB-IoT can send data to the cloud and can directly communicate with other NB-IoT nodes setting up a fog computing paradigm on peer-to-peer subnetworks. This approach may be crucial for the development of complex IoT infrastructures while providing high flexibility.

The Internet of Things (IoT) and its applications in industrial settings are set to bring in the fourth industrial revolution. The industrial environment consisting of high profile manufacturing plants and a variety of equipment is inherently characterized by high reflectiveness, causing significant multi-path components that affect the propagation of wireless communications—a challenge among others that needs to be resolved. This paper provides a detailed insight into Narrow-Band IoT (NB-IoT), Industrial IoT (IIoT), and Wireless Sensor Networks (WSN) within the context of indoor industrial environments. It presents the applications of NB-IoT for industrial settings, such as the challenges associated with these applications. Furthermore, future research directions were put forth in the areas of NB-IoT network management using self-organizing network (SON) technology, edge computing for scalability enhancement, security in NB-IoT generated data, and proposing a suitable propagation model for reliable wireless communications.

Machine Learning (ML) techniques can play a pivotal role in energy efficient IoT networks by reducing the unnecessary data from transmission. With such an aim, this work combines a low-power, yet computationally capable processing unit, with an NB-IoT radio into a smart gateway that can run ML algorithms to smart transmit visual data over the NB-IoT network. The proposed smart gateway utilizes supervised and unsupervised ML algorithms to optimize the visual data in terms of their size and quality before being transmitted over the air. This relaxes the channel occupancy from an individual NB-IoT radio, reduces its energy consumption and also minimizes the transmission time of data. Our on-field results indicate up to 93% reductions in the number of NB-IoT radio transmissions, up to 90.5% reductions in the NB-IoT radio energy consumption and up to 90% reductions in the data transmission time.

Internet of Things (IoT) is a key business driver for the upcoming fifth-generation (5G) mobile networks, which in turn will enable numerous innovative IoT applications such as smart city, mobile health, and other massive IoT use cases being defined in 5G standards. To truly unlock the hidden value of such mission-critical IoT applications in a large scale in the 5G era, advanced self-protection capabilities are entailed in 5G-based Narrowband IoT (NB-IoT) networks to efficiently fight off cyber-attacks such as widespread Distributed Denial of Service (DDoS) attacks. However, insufficient research has been conducted in this crucial area, in particular, few if any solutions are capable of dealing with the multiple encapsulated 5G traffic for IoT security management. This paper proposes and prototypes a new security framework to achieve the highly desirable self-organizing networking capabilities to secure virtualized, multitenant 5G-based IoT traffic through an autonomic control loop featured with efficient 5G-aware traffic filtering. Empirical results have validated the design and implementation and demonstrated the efficiency of the proposed system, which is capable of processing thousands of 5G-aware traffic filtering rules and thus enables timely protection against large-scale attacks.

Narrowband Internet of Things (NB-IoT) has quickly become a leading technology in the deployment of IoT systems and services, owing to its appealing features in terms of coverage and energy efficiency, as well as compatibility with existing mobile networks. Increasingly, IoT services and applications require location information to be paired with data collected by devices; NB-IoT still lacks, however, reliable positioning methods. Time-based techniques inherited from long-term evolution (LTE) are not yet widely available in existing networks and are expected to perform poorly on NB-IoT signals due to their narrow bandwidth. This investigation proposes a set of strategies for NB-IoT positioning based on fingerprinting that use coverage and radio information from multiple cells. The proposed strategies were evaluated on two large-scale datasets made available under an open-source license that include experimental data from multiple NB-IoT operators in two large cities: Oslo, Norway, and Rome, Italy. Results showed that the proposed strategies, using a combination of coverage and radio information from multiple cells, outperform current state-of-the-art approaches based on single cell fingerprinting, with a minimum average positioning error of about 20 m when using data for a single operator that was consistent across the two datasets vs. about 70 m for the current state-of-the-art approaches. The combination of data from multiple operators and data smoothing further improved positioning accuracy, leading to a minimum average positioning error below 15 m in both urban environments.

Abstract Wireless Sensor Network (WSN) is a wireless network formed by a group of sensors with wireless transceiver capabilities, connected in a multi-hop autonomous manner. It has several advantages: low traffic, greater stability, longer wireless communication, and higher coverage areas at a lower cost. The incorporation of new NB-IoT technologies in wireless sensor networks, combining the advantages of both and the establishment of NB-IoT-based wireless sensor networks, has a very promising application in defense and military, medical, intelligent transportation, and commercial applications. This study first investigates both WSN and NB-IoT technologies separately and then combines them to investigate the networking structure of NB-IoT and WSN as well as the related technologies based on the fusion. Then the coverage method of the traditional network node redeployment of wireless sensors is described, and many problems such as poor node connectivity and low coverage are caused by the traditional method due to the lack of local search of subgroup nodes. The initialization of the nodes is carried out. The global information exchange is combined with the subgroup to determine the detectable area of the wireless sensor, and the calculus method is used for the irregular area to obtain the optimal network node so that the nodes of the wireless sensor network can be redeployed.

Narrowband-Internet of Things (NB-IoT) displays high-quality connectivity underpinned by fifth-generation (5G) networks to cover a wide array of IoT applications. The devices’ development and integration into different smart systems require permanent control, supervision, and the study of power consumption models to determine the performance of the network topology and allow for the measurement of the efficiency of the network topology’s application. This paper reports on an architecture and open-sourced simulation that was developed to study NB-IoT in Device-to-Device (D2D) mode, which includes the Physical (PHY), network, and application layers, as well as a queuing model, the model for uplink and downlink delays, the throughput, the overall NB-IoT D2D network performance, and the energy consumption based on the Low Energy Adaptive Clustering Hierarchy (LEACH) protocol. Our results prove that the suggested framework contributes to a reduction in power consumption, a minimization of queuing delays, a decrease in communication cost, a reduction in inter-cluster collisions, and the prevention of attacks from malicious nodes. Consequently, the framework manages the battery’s State of Charge (SOC), improves the battery’s State of Health (SOH), and maximizes the whole network lifetime. The proposed framework, the code of which has been open-sourced, can be effectively used for scientific research and development purposes to evaluate different parameters and improve the planning of NB-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.

UAV is widely used in civil applications such as environmental hazards monitoring, traffic management and pollution monitoring, all of those contribute to smart city development. Thanks to its high mobility and feasibility, UAVs can be employed as a base station, gathering data from IoT devices distribute in a certain area during its flight. In this case, an appropriate trajectory and suitable parameters set is necessary to achieve better performance. This thesis studies a scenario of NB-IoT machine-type communication network served by an unmanned aerial base station (UAB). In this scenario, the user devices are deployed with Tomas Cluster Process (TCP)[19]. Some of the nodes are named parent nodes and generated with Poisson Point Process (PPP). One single UAB is employed and its trajectory is predefined with a Travelling Salesman Problem model among the parent nodes. All the devices only generate one data packet for UL, whose activation time and expiration time is considered. Due to NB-IoT protocols, the number of resource units available on NPUSCH and the data rate for IoT devices is constrained. This study makes the network throughput and the number of users served as the main basis of performance evaluation, the variation of UAB speed, NPRACH periodicity, deployment variance, and size of the data packet as influencing factors. Finally, we present an analysis of how these parameters affect the overall performance and how the optimal configuration may be chosen according to arbitrary criteria.

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

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.

Cette thèse étudie le problème de planification des ressources pour les réseaux IoT longues portées basés sur les technologies NB-IoT et LoRa. Dans les deux cas, on suppose que les capteurs et les collecteurs sont distribués suivant des processus de points de Poisson spatial indépendants marqués par le caractère aléatoire du canal. Pour le NB-IoT, nous élaborons un modèle de dimensionnement statistique qui estime le nombre de ressources radio nécessaires en fonction du délai d’accès toléré, de la densité des nœuds actifs, des collecteurs et de la configuration de l’antenne. Pour le réseau LoRa, nous proposons une technique d’allocation de plusieurs sous-bandes pour atténuer le niveau élevé d’interférence induit par les nœuds qui transmettent avec le même facteur d’étalement. Pour allouer dynamiquement le facteur d’étalement et la puissance, nous présentons une approche d’apprentissage automatique avec multi-agents qui permet d’améliorer l’efficacité énergétique
In this thesis, we focus on radio resource planning issues for low power wide area networks based on NB-IoT and LoRa technologies. In both cases, the average behavior of the network is considered by assuming the sensors and the collectors are distributed according to independent random Poisson Point Process marked by the channel randomness. For the NB-IoT, we elaborate a statistical dimensioning model that estimates the number of radio resources in the network depending on the tolerated delay access, the density of active nodes, the collectors, and the antenna configuration with single and multi-user transmission. For the LoRa network, we propose a multi-sub band allocation technique to mitigate the high level of interference induced by nodes that transmit with the same spreading factor. To dynamically allocate the spreading factor and the power, we present a Q-learning multi-agent approach to improve the energy efficiency

The Internet of Things (IoT) is a fundamental pillar in the digital transformation since it enables the interaction with the physical world by means of sensing and actuation. 3GPP recognized the importance of IoT by introducing new features aimed at supporting this technology. In details, in Rel.13, the 3GPP has launched the NB-IoT to provide support for LPWAN. Since these devices will be distributed also in such area where the terrestrial networks are not feasible or commercially viable, satellite networks will have a complementary role thanks to their capability to provide worldwide connectivity through their large footprint size and short service deployment time. In this context, the aim of this thesis is to analyze the feasibility of integration of the NB-IoT technology with satellite communication systems focusing on the Random-Access Procedure. Indeed, the RA is the most critical procedure since it allows the UE to achieve uplink synchronization, obtain the permanent ID, and get the resources for the uplink transmission. The objective of the thesis is the assessment of the preamble detection in the SatCom environment. The elaborate is divided in four chapters: the first one highlights the main characteristics of the NBIoT technology. In the second chapter, a detail description of the synchronization and RA procedures is presented with a review of the Stat of Art of the detection of the preamble; in the third chapter the main features of SatCom systems are shown, with particular emphasis on the impairments which could hamper the RA procedure. In the fourth chapter, a thorough analysis on the detection process and the implementation of the transmission and reception chain, obtained by the means of simulator built in MATLAB, are provided, with the results. Finally, chapter five concludes this work.

L'Internet des objets (IoT, pour Internet of Things, en anglais) ouvre la porte vers la réalisation de nouvelles applications, telles que les compteurs intelligents et le suivi environnemental, destinées à adresser nos défis sociétaux et écologiques actuels et futurs. Les objets, possiblement mobiles ou distants, nécessitent une connectivité sans fil pour la centralisation des données et le contrôle à distance. Les réseaux longue portée et basse consommation (LPWA, pour Low Power Wide Area, en anglais) offrent des transmissions radio bande étroite avec une couverture à l’échelle typique d’une ville, tout en respectant les contraintes de consommation énergétique bas coût des objets. Intégrer la possibilité de localiser ces objets ajouterait de la valeur à leurs données et permettrait leur suivi géographique. Voilà pourquoi c'est un domaine de recherche très actif actuellement. L'utilisation du temps de propagation des signaux radio de communication, sans intégration supplémentaire de modules matériels dédiés à la localisation, est une approche très intéressante pour la complexité, la consommation et le coût des objets. Néanmoins la radio localisation dans les réseaux LPWA pose des défis liés d'une part aux transmissions à bande étroite qui n'offrent pas une résolution temporelle suffisante et d'autre part aux canaux de propagation qui peuvent introduire des biais sur les estimées de position. Cette thèse adresse ces défis en étudiant un système de mesure multicanaux de distance pour les réseaux LPWA. La combinaison cohérente des signaux bande étroite transmis séquentiellement sur des canaux différents améliore la précision d’estimation des temps de propagation et permet de résoudre en partie les multi-trajets pour une meilleure précision de localisation. Cette technique basée sur les signaux à bande instantanée étroite conserve la capacité longue portée des transmissions et reste compatible avec les réseaux LPWA. Un modèle détaillé prenant en compte les imperfections matérielles ainsi que les besoins protocolaires pour la synchronisation en temps, fréquence et phase est développé. Basé sur ce modèle, les variantes des architectures des émetteurs-récepteurs radios et leurs impacts sur la cohérence de phase pour l’estimation multicanaux de distance sont discutés. Les limites théoriques de précision sont dérivées pour la propagation en espace libre et dans des canaux de propagation multi-trajets, illustrant l’amélioration de précision possible entre l'approche multicanaux et l'approche monocanal pour l'estimation de distance. Des estimateurs de distance sont développés et appliqués aux signaux radio simulés afin de montrer que leurs performances atteignent les limites théoriques. Ces résultats de simulation sont validés avec des expérimentations menées avec un démonstrateur implémenté avec une radio logicielle (SDR, pour Software Defined Radio, en anglais). Les tests terrains réalisés en environnement urbain permettent de confirmer l'apport d'un système d'estimation multicanaux de distance, en combinaison avec du traitement de signal avancé, pour fournir une fonctionnalité de localisation intrinsèque et précise pour les réseaux LPWA
The Internet of Things (IoT) is an enabler to new applications, such as smart metering and environmental monitoring, intended to address current and future societal and ecological challenges. Things, possibly mobile or in distant locations, require wireless connectivity for data collection and remote control. Low Power Wide Area (LPWA) networks provide city-scale long-range, narrowband radio transmissions respecting the energy constraints of battery-powered low-cost objects. Being capable to localize these objects will add value to their data, enables tracking applications and is therefore a demanded and recent research topic. Precise and accurate radio signal delay based positioning without integrating additional hardware but taking advantage of intrinsic wireless communication signals is appealing in terms of device complexity, cost and energy consumption. However, radio localization within LPWA networks is challenging due to narrowband transmissions, resulting in a lack of delay precision as well as due to radio propagation channels, which degrade the accuracy of location estimates. This work addresses both challenges by investigating a multi-channel ranging system for LPWA networks. Coherently combining multiple sequentially transmitted narrowband signals on different radio channels improves delay estimation precision and allows resolving multipath channels for refined positioning accuracy. This scheme, based on instantaneous narrowband signals, conserves the LPWA long-range feature and is hence compatible with LPWA networks. A detailed signal model considering hardware imperfections as well as the required protocol exchanges for time, frequency and phase synchronization is developed. Based on this model, the requirements on radio transceiver architectures regarding the necessary phase coherence for multi-channel ranging are discussed. Lower bounds on the ranging precision are derived for both, free-space and multipath propagation channels, illustrating the improved precision compared to narrowband single channel ranging. Numerical simulations of radio signals for the two-way multi-channel ranging protocol illustrate that the performance of developed range estimators attains the theoretical precision bound and pave the way towards implementation. A flexible Software Defined Radio (SDR) based demonstrator is implemented to validate simulation results. Field trials in real urban outdoor environments are in accordance with simulation results and prove how scalable multi-channel ranging, in combination with advanced signal processing methods, will be an enabler towards precise and accurate localization in LPWA networks

Nowadays it is more clear that the Internet of things (IoT) is not a transient trend but a completely new industry. The internet of things has the capability to enhance current industries (Industry 4.0), as well as to help protecting the environment and people. The latter is the case with the system developed and described in this thesis. The possibilities that IoT brings are due to the interconnection of heterogeneous embedded devices to the internet. This thesis focus on LPWANs (Low Power Wide Area Networks), which is a new set of technologies specifically design for the needs of IoT devices.Due to the recent deploy of NB-IoT (Narrow Band IoT) networks it has become more difficult to know what LPWAN is best for a certain application. Thus, the first half of this thesis involves the comparative study of NB-IoT and LoRaWAN LPWANs. This comparison required an in depth study of each technology, specially on the physical and datalink layers. The comparison briefly displays the main characteristics of each technology and explain the main conclusions in a concise manner. The second part of the thesis describes the development of a GNSS tracker. This tracker will be used on train wagons carrying goods that are dangerous for people and the environment. This thesis report describes the different steps taken, from the requirement specification to the partial development of the software.

La quinta generación de redes móviles (5G) se encuentra a la vuelta de la esquina. Se espera provea de beneficios extraordinarios a la población y que resuelva la mayoría de los problemas de las redes 4G actuales. El éxito de 5G, cuya primera fase de estandarización ha sido completada, depende de tres pilares: comunicaciones tipo-máquina masivas, banda ancha móvil mejorada y comunicaciones ultra fiables y de baja latencia (mMTC, eMBB y URLLC, respectivamente). En esta tesis nos enfocamos en el primer pilar de 5G, mMTC, pero también proveemos una solución para lograr eMBB en escenarios de distribución masiva de contenidos. Específicamente, las principales contribuciones son en las áreas de: 1) soporte eficiente de mMTC en redes celulares; 2) acceso aleatorio para el reporte de eventos en redes inalámbricas de sensores (WSNs); y 3) cooperación para la distribución masiva de contenidos en redes celulares. En el apartado de mMTC en redes celulares, esta tesis provee un análisis profundo del desempeño del procedimiento de acceso aleatorio, que es la forma mediante la cual los dispositivos móviles acceden a la red. Estos análisis fueron inicialmente llevados a cabo por simulaciones y, posteriormente, por medio de un modelo analítico. Ambos modelos fueron desarrollados específicamente para este propósito e incluyen uno de los esquemas de control de acceso más prometedores: access class barring (ACB). Nuestro modelo es uno de los más precisos que se pueden encontrar en la literatura y el único que incorpora el esquema de ACB. Los resultados obtenidos por medio de este modelo y por simulación son claros: los accesos altamente sincronizados que ocurren en aplicaciones de mMTC pueden causar congestión severa en el canal de acceso. Por otro lado, también son claros en que esta congestión se puede prevenir con una adecuada configuración del ACB. Sin embargo, los parámetros de configuración del ACB deben ser continuamente adaptados a la intensidad de accesos para poder obtener un desempeño óptimo. En la tesis se propone una solución práctica a este problema en la forma de un esquema de configuración automática para el ACB; lo llamamos ACBC. Los resultados muestran que nuestro esquema puede lograr un desempeño muy cercano al óptimo sin importar la intensidad de los accesos. Asimismo, puede ser directamente implementado en redes celulares para soportar el tráfico mMTC, ya que ha sido diseñado teniendo en cuenta los estándares del 3GPP. Además de los análisis descritos anteriormente para redes celulares, se realiza un análisis general para aplicaciones de contadores inteligentes. Es decir, estudiamos un escenario de mMTC desde la perspectiva de las WSNs. Específicamente, desarrollamos un modelo híbrido para el análisis de desempeño y la optimización de protocolos de WSNs de acceso aleatorio y basados en cluster. Los resultados muestran la utilidad de escuchar el medio inalámbrico para minimizar el número de transmisiones y también de modificar las probabilidades de transmisión después de una colisión. En lo que respecta a eMBB, nos enfocamos en un escenario de distribución masiva de contenidos, en el que un mismo contenido es enviado de forma simultánea a un gran número de usuarios móviles. Este escenario es problemático, ya que las estaciones base de la red celular no cuentan con mecanismos eficientes de multicast o broadcast. Por lo tanto, la solución que se adopta comúnmente es la de replicar e contenido para cada uno de los usuarios que lo soliciten; está claro que esto es altamente ineficiente. Para resolver este problema, proponemos el uso de esquemas de network coding y de arquitecturas cooperativas llamadas nubes móviles. En concreto, desarrollamos un protocolo para la distribución masiva de contenidos, junto con un modelo analítico para su optimización. Los resultados demuestran que el modelo propuesto es simple y preciso, y que el protocolo puede reducir el con
La cinquena generació de xarxes mòbils (5G) es troba molt a la vora. S'espera que proveïsca de beneficis extraordinaris a la població i que resolga la majoria dels problemes de les xarxes 4G actuals. L'èxit de 5G, per a la qual ja ha sigut completada la primera fase del qual d'estandardització, depén de tres pilars: comunicacions tipus-màquina massives, banda ampla mòbil millorada, i comunicacions ultra fiables i de baixa latència (mMTC, eMBB i URLLC, respectivament, per les seues sigles en anglés). En aquesta tesi ens enfoquem en el primer pilar de 5G, mMTC, però també proveïm una solució per a aconseguir eMBB en escenaris de distribució massiva de continguts. Específicament, les principals contribucions són en les àrees de: 1) suport eficient de mMTC en xarxes cel·lulars; 2) accés aleatori per al report d'esdeveniments en xarxes sense fils de sensors (WSNs); i 3) cooperació per a la distribució massiva de continguts en xarxes cel·lulars. En l'apartat de mMTC en xarxes cel·lulars, aquesta tesi realitza una anàlisi profunda de l'acompliment del procediment d'accés aleatori, que és la forma mitjançant la qual els dispositius mòbils accedeixen a la xarxa. Aquestes anàlisis van ser inicialment dutes per mitjà de simulacions i, posteriorment, per mitjà d'un model analític. Els models van ser desenvolupats específicament per a aquest propòsit i inclouen un dels esquemes de control d'accés més prometedors: el access class barring (ACB). El nostre model és un dels més precisos que es poden trobar i l'únic que incorpora l'esquema d'ACB. Els resultats obtinguts per mitjà d'aquest model i per simulació són clars: els accessos altament sincronitzats que ocorren en aplicacions de mMTC poden causar congestió severa en el canal d'accés. D'altra banda, també són clars en què aquesta congestió es pot previndre amb una adequada configuració de l'ACB. No obstant això, els paràmetres de configuració de l'ACB han de ser contínuament adaptats a la intensitat d'accessos per a poder obtindre unes prestacions òptimes. En la tesi es proposa una solució pràctica a aquest problema en la forma d'un esquema de configuració automàtica per a l'ACB; l'anomenem ACBC. Els resultats mostren que el nostre esquema pot aconseguir un acompliment molt proper a l'òptim sense importar la intensitat dels accessos. Així mateix, pot ser directament implementat en xarxes cel·lulars per a suportar el trànsit mMTC, ja que ha sigut dissenyat tenint en compte els estàndards del 3GPP. A més de les anàlisis descrites anteriorment per a xarxes cel·lulars, es realitza una anàlisi general per a aplicacions de comptadors intel·ligents. És a dir, estudiem un escenari de mMTC des de la perspectiva de les WSNs. Específicament, desenvolupem un model híbrid per a l'anàlisi de prestacions i l'optimització de protocols de WSNs d'accés aleatori i basats en clúster. Els resultats mostren la utilitat d'escoltar el mitjà sense fil per a minimitzar el nombre de transmissions i també de modificar les probabilitats de transmissió després d'una col·lisió. Pel que fa a eMBB, ens enfoquem en un escenari de distribució massiva de continguts, en el qual un mateix contingut és enviat de forma simultània a un gran nombre d'usuaris mòbils. Aquest escenari és problemàtic, ja que les estacions base de la xarxa cel·lular no compten amb mecanismes eficients de multicast o broadcast. Per tant, la solució que s'adopta comunament és la de replicar el contingut per a cadascun dels usuaris que ho sol·liciten; és clar que això és altament ineficient. Per a resoldre aquest problema, proposem l'ús d'esquemes de network coding i d'arquitectures cooperatives anomenades núvols mòbils. En concret, desenvolupem un protocol per a realitzar la distribució massiva de continguts de forma eficient, juntament amb un model analític per a la seua optimització. Els resultats demostren que el model proposat és simple i precís
The 5th generation (5G) of mobile networks is just around the corner. It is expected to bring extraordinary benefits to the population and to solve the majority of the problems of current 4th generation (4G) systems. The success of 5G, whose first phase of standardization has concluded, relies in three pillars that correspond to its main use cases: massive machine-type communication (mMTC), enhanced mobile broadband (eMBB), and ultra-reliable low latency communication (URLLC). This thesis mainly focuses on the first pillar of 5G: mMTC, but also provides a solution for the eMBB in massive content delivery scenarios. Specifically, its main contributions are in the areas of: 1) efficient support of mMTC in cellular networks; 2) random access (RA) event-reporting in wireless sensor networks (WSNs); and 3) cooperative massive content delivery in cellular networks. Regarding mMTC in cellular networks, this thesis provides a thorough performance analysis of the RA procedure (RAP), used by the mobile devices to switch from idle to connected mode. These analyses were first conducted by simulation and then by an analytical model; both of these were developed with this specific purpose and include one of the most promising access control schemes: the access class barring (ACB). To the best of our knowledge, this is one of the most accurate analytical models reported in the literature and the only one that incorporates the ACB scheme. Our results clearly show that the highly-synchronized accesses that occur in mMTC applications can lead to severe congestion. On the other hand, it is also clear that congestion can be prevented with an adequate configuration of the ACB scheme. However, the configuration parameters of the ACB scheme must be continuously adapted to the intensity of access attempts if an optimal performance is to be obtained. We developed a practical solution to this problem in the form of a scheme to automatically configure the ACB; we call it access class barring configuration (ACBC) scheme. The results show that our ACBC scheme leads to a near-optimal performance regardless of the intensity of access attempts. Furthermore, it can be directly implemented in 3rd Generation Partnership Project (3GPP) cellular systems to efficiently handle mMTC because it has been designed to comply with the 3GPP standards. In addition to the analyses described above for cellular networks, a general analysis for smart metering applications is performed. That is, we study an mMTC scenario from the perspective of event detection and reporting WSNs. Specifically, we provide a hybrid model for the performance analysis and optimization of cluster-based RA WSN protocols. Results showcase the utility of overhearing to minimize the number of packet transmissions, but also of the adaptation of transmission parameters after a collision occurs. Building on this, we are able to provide some guidelines that can drastically increase the performance of a wide range of RA protocols and systems in event reporting applications. Regarding eMBB, we focus on a massive content delivery scenario in which the exact same content is transmitted to a large number of mobile users simultaneously. Such a scenario may arise, for example, with video streaming services that offer a particularly popular content. This is a problematic scenario because cellular base stations have no efficient multicast or broadcast mechanisms. Hence, the traditional solution is to replicate the content for each requesting user, which is highly inefficient. To solve this problem, we propose the use of network coding (NC) schemes in combination with cooperative architectures named mobile clouds (MCs). Specifically, we develop a protocol for efficient massive content delivery, along with the analytical model for its optimization. Results show the proposed model is simple and accurate, and the protocol can lead to energy savings of up to 37 percent when compared to the traditional approach.
Leyva Mayorga, I. (2018). On reliable and energy efficient massive wireless communications: the road to 5G [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/115484
TESIS

Diploma thesis deals with the implementation of LTE Cat-M1 technology in simulator NS--3 (Network Simulator 3). The theoretical part of the thesis summarizes key terms concerning IoT (Internet of Things), M2M (Machine-to-Machine) communication, LTE (Long Term Evolution) and LPWA (Low-Power Wide Area) networks. The practical part summarizes the possibilities of currently available modules for cellular technologies for NS-3, ie. the LENA module and the subsequent extension of LENA+ and ELENA. Simulation scenarios offer a comparison of LTE/LTE-A and LTE Cat-M1 (also known as eMTC - enhanced Machine Type Communication) technologies for M2M communication. The results of the simulations are well-arranged in the form of graphs and discussed at the end of the thesis.

AbstractThe significant expansion of cellular networks has increased their potential to support a wide range of use cases beyond their original purpose of providing broadband access. One such development is using cellular networks to support the Internet of Things (IoT), called Cellular IoT (CIoT). The growth of CIoT is an important trend in the evolution of cellular networks, it leads to broader and more comprehensive ecosystem circumstances. The extensive IoT business evolution is transforming a diverse sector, including health, smart cities, security, and agriculture. Nevertheless, a large scale with very different characteristics and use cases struggle with connectivity challenges due to the unique traffic features of massive IoT and the tremendous density of IoT devices. This study aims to identify the critical obstacles that hinder the widespread deployment of IoT over cellular networks and suggest an innovative algorithm to mitigate them effectively. We discovered that the primary challenges revolve around three specific areas: connection setup, network resource management, and energy consumption. In this regard, we investigate the integration of massive Machine-Type Communication (mMTC) into cellular networks, focusing on the performance of Narrowband IoT (NB-IoT) in supporting mMTC.

AbstractSpatially Distributed Wireless Networks (SDWN) are one of the basic technologies for the Internet of Things (IoT) and (Industrial) Internet of Things (IIoT) applications. These SDWN for many of these applications has strict requirements such as low cost, simple installation and operations, and high potential flexibility and mobility. Among the different Narrowband Wireless Wide Area Networking (NBWWAN) technologies, which are introduced to address these categories of wireless networking requirements, Narrowband Internet of Things (NB-IoT) is getting more traction due to attractive system parameters, energy-saving mode of operation with low data rates and bandwidth, and its applicability in 5G use cases. Since several technologies are available and because the underlying use cases come with various requirements, it is essential to perform a systematic comparative analysis of competing technologies to choose the right technology. It is also important to perform testing during different phases of the system development life cycle. This paper describes the systematic test environment for automated testing of radio communication and systematic measurements of the performance of NB-IoT.