Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-10-22T10:13:08Z No. of bitstreams: 2 Dissertação - Diego Cruz Abrahão - 2015.pdf: 9765017 bytes, checksum: 6f29592215e8451edda4aa5ad24238f4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-10-22T10:15:40Z (GMT) No. of bitstreams: 2 Dissertação - Diego Cruz Abrahão - 2015.pdf: 9765017 bytes, checksum: 6f29592215e8451edda4aa5ad24238f4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-10-22T10:15:40Z (GMT). No. of bitstreams: 2 Dissertação - Diego Cruz Abrahão - 2015.pdf: 9765017 bytes, checksum: 6f29592215e8451edda4aa5ad24238f4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-03-19 / In this paper we propose two schemes for allocating resource blocks for transmission LTE downlink to maximize the throughput of the system, to guarantee QoS (Quality of Service) parameters for the users and reduce the data loss rate of network. The first proposed scheme uses the Max-min criterion and the second employs a fuzzy inference system to calculate the priorities of users and make scheduling decisions. Both schemes use an estimated effective bandwidth of traffic flows of users. The effective bandwidth of a traffic flow is the rate required to meet a criterion of probability of data loss rate. In this work, the effective bandwidth is estimated adaptively by the parameters of multifractal modeling βMWM (β-Multifractal Wavelet Mode). Are made simulations of the algorithms proposed, considering different propagation models with multipath fading and with different numbers of users in the network. The simulation results are compared with other algorithms presented in the literature, using parameters such as: throughput of the system, data loss rate and fairness index. It is also proposed to use predict of the SNR (Signal-to-Noise Ratio) of users, in the scheduling algorithms, using linear prediction of multi-step filter, in view of the delay in receipt of the channel quality information of the users in the base station and the variation of the signal propagation conditions. The multi-step prediction filter is used with the algorithms of allocation of resource blocks proposed in this work to estimate the signal-to-noise-ratio of users and set well, modulation schemes and code to be used in the LTE network. / Neste trabalho são propostos dois esquemas de alocação de blocos de recurso para a transmissão de downlink LTE, visando maximizar a vazão de dados total do sistema, garantir parâmetros de QoS (Quality of Service) dos usuários e diminuir a taxa de perda de dados da rede. O primeiro esquema proposto utiliza o critério Max-min e o segundo emprega um sistema de inferência fuzzy para calcular as prioridades dos usuários e tomar decisões de escalonamento. Ambos os esquemas utilizam estimações de banda efetiva dos fluxos de tráfego dos usuários. A banda efetiva de um fluxo de tráfego é a taxa necessária para atender a um critério de probabilidade de perda de dados. Neste trabalho, a banda efetiva é estimada de forma adaptativa, através dos parâmetros da modelagem multifractal βMWM (β-Multifractal Wavelet Mode). São realizadas simulações dos algoritmos propostos de alocação de blocos de recurso, considerando diferentes modelos de propagação com desvanecimento de multipercursos e com diferentes quantidades de usuários na rede. Os resultados das simulações são comparados com outros algoritmos apresentados na literatura, através de parâmetros, como: vazão de dados do sistema, taxa de perda de dados e índice de justiça. É proposta ainda, a utilização da predição da relação sinalruído (SNR - Signal-to-Noise Ratio) dos usuários nos algoritmos de escalonamento, utilizando filtro de predição linear de multi-passos, tendo em vista o atraso no recebimento da informação da qualidade do canal dos usuários na estação base e a variação das condições de propagação do sinal. O filtro de predição de multi-passos é utilizado junto com os algoritmos de alocação de blocos de recurso propostos neste trabalho, para estimar a relação sinal-ruído dos usuários e definir, assim, os esquemas de modulação e código a serem utilizados na rede LTE.

Radio access technologies for cellular mobile networks are continuously being evolved to meet the future demands for higher data rates, and lower end‐to‐end delays. In the research and development of LTE, radio network simulations play an essential role. The evolution of parallel processing hardware makes it desirable to exploit the potential gains of parallelizing LTE radio network simulations using multithreading techniques in contrast to distributing experiments over processors as independent simulation job processes. There is a hypothesis that parallel speedup gain diminishes when running many parallel simulation jobs concurrently on the same machine due to the increased memory requirements. A proposed multithreaded prototype of the Ericsson LTE simulator has been constructed, encapsulating scheduling, execution and synchronization of asynchronous physical layer computations. In order to provide implementation transparency, an algorithm has been proposed to sort and synchronize log events enabling a sequential logging model on top of non‐deterministic execution. In order to evaluate and compare multithreading techniques to parallel simulation job distribution, a large number of experiments have been carried out for four very diverse simulation scenarios. The evaluation of the results from these experiments involved analysis of average measured execution times and comparison with ideal estimates derived from Amdahl’s law in order to analyze overhead. It has been shown that the proposed multithreaded task‐oriented framework provides a convenient way to execute LTE physical layer models asynchronously on multi‐core processors, still providing deterministic results that are equivalent to the results of a sequential simulator. However, it has been indicated that distributing parallel independent jobs over processors is currently more efficient than multithreading techniques, even though the achieved speedup is far from ideal. This conclusion is based on the observation that the overhead caused by increased memory requirements, memory access and system bus congestion is currently smaller than the thread management and synchronization overhead of the proposed multithreaded Java prototype.

Les réseaux fixes et mobiles font face à une croissance dramatique du trafic de données, qui est principalement due à la distribution de contenus vidéo. Les opérateurs Télécoms envisagent donc de décentraliser la distribution de contenus dans les futures architectures convergées fixe-mobile (FMC). Cette décentralisation, conjointement au déploiement d'un cœur de réseau mobile distribué, sera un élément majeur des futurs réseaux 5G. L'approche SIPTO définie par 3GPP permet déjà le délestage sur le réseau fixe du trafic mobile, et pourra donc être utilisée en 5G. SIPTO s'appuie sur la distribution des passerelles de données (PGW) qui permet ainsi de décharger le cœur du réseau mobile actuel. Cependant, dans certains cas de mobilité des usagers, SIPTO ne supporte pas la continuité de session, quand il est nécessaire de changer de PGW, donc de modifier l'adresse IP du terminal. Cette thèse commence par quantifier le gain apporté par le délestage du trafic mobile en termes de capacité requise pour différentes portions du réseau. Un état de l'art des différentes solutions de délestage du trafic de données mobiles est fourni, démontrant qu'aucune des solutions existantes ne supporte la continuité de service pour les sessions de longue durée. C'est pourquoi, cette thèse propose des solutions pour supporter une mobilité transparente ; ces solutions s'appuient à la fois sur SIPTO et sur le protocole MultiPath TCP (MPTCP). Les protocoles du 3GPP sont inchangés car la continuité est maintenue par les extrémités. Enfin, ces solutions sont appliquées aux différentes implémentations d'architectures FMC envisagées à ce jour. / Fixed and mobile networks are currently experiencing a dramatic growth in terms of data traffic, mainly driven by video content distribution. Telecoms operators are thus considering de-centralizing content distribution architecture for future Fixed and Mobile Converged (FMC) network architectures. This decentralization, together with a distributed mobile EPC, would be used for future 5G networks. Mobile data offloading, in particular SIPTO approaches, already represent a good implementation model for 5G network as it allows the use of distributed IP edges to offload Selected IP traffic off the currently centralized mobile core network. However, in some cases, SIPTO does not support session continuity during users' mobility. This is due to the fact that user's mobility may imply packet gateway (PGW) relocation and thus a modification of the UE's IP address.This PhD thesis first quantifies the gain, in terms of bandwidth demands on various network portions, brought by the generalized use of mobile traffic offloading. A state of art of existing mobile data offloading solutions is presented, showing that none of the existing solutions solve the problem of session continuity for long-lived sessions. This is why, in the context of future FMC mobile network architectures, the PhD thesis proposes solutions to provide seamless mobility for users relying on SIPTO with the help of Multipath TCP (MPTCP). 3GPP standards are not modified, as session continuity is ensured by end-points. Lastly, the proposed solutions are mapped on different architecture options considered for future FMC networks.

L'émergence et la croissance rapide des services multimédia dans les réseaux IP ont créé de nouveaux défis pour les fournisseurs de services réseau, qui, au-delà de la Qualité de Service (QoS) issue des paramètres techniques de leur réseau, doivent aussi garantir la meilleure qualité de perception utilisateur (Quality of Experience, QoE) dans des réseaux variés avec différentes technologies d'accès. Habituellement, différentes méthodes et techniques sont utilisées pour prédire le niveau de satisfaction de l'utilisateur, en analysant l'effet combiné de multiples facteurs. Dans cette thèse, nous nous intéressons à la commande du réseau en intégrant à la fois des aspects qualitatifs (perception du niveau de satisfaction de l'usager) et quantitatifs (mesure de paramètres réseau) dans l'objectif de développer des mécanismes capables, à la fois, de s'adapter à la variabilité des mesures collectées et d'améliorer la qualité de perception. Pour ce faire, nous avons étudié le cas de deux services multimédia populaires, qui sont : le streaming vidéo, et la voix sur IP (VoIP). Nous investiguons la QoE utilisateur de ces services selon trois aspects : (1) les méthodologies d'évaluation subjective de la QoE, dans le cadre d'un service vidéo, (2) les techniques d'adaptation de flux vidéo pour garantir un certain niveau de QoE, et (3) les méthodes d'allocation de ressource, tenant compte de la QoE tout en économisant l'énergie, dans le cadre d'un service de VoIP (LTE-A). Nous présentons d'abord deux méthodes pour récolter des jeux de données relatifs à la QoE. Nous utilisons ensuite ces jeux de données (issus des campagnes d'évaluation subjective que nous avons menées) pour comprendre l'influence de différents paramètres (réseau, terminal, profil utilisateur) sur la perception d'un utilisateur d'un service vidéo. Nous proposons ensuite un algorithme de streaming vidéo adaptatif, implémenté dans un client HTTP, et dont le but est d'assurer un certain niveau de QoE et le comparons à l'état de l'art. Notre algorithme tient compte de trois paramètres de QoS (bande passante, taille de mémoires tampons de réception et taux de pertes de paquets) et sélectionne dynamiquement la qualité vidéo appropriée en fonction des conditions du réseau et des propriétés du terminal de l'utilisateur. Enfin, nous proposons QEPEM (QoE Power Efficient Method), un algorithme d'ordonnancement basé sur la QoE, dans le cadre d'un réseau sans fil LTE, en nous intéressant à une allocation dynamique des ressources radio en tenant compte de la consommation énergétique / The emerging and fast growth of multimedia services have created new challenges for network service providers in order to guarantee the best user's Quality of Experience (QoE) in diverse networks with distinctive access technologies. Usually, various methods and techniques are used to predict the user satisfaction level by studying the combined impact of numerous factors. In this thesis, we consider two important multimedia services to evaluate the user perception, which are: video streaming service, and VoIP. This study investigates user's QoE that follows three directions: (1) methodologies for subjective QoE assessment of video services, (2) regulating user's QoE using video a rate adaptive algorithm, and (3) QoE-based power efficient resource allocation methods for Long Term Evaluation-Advanced (LTE-A) for VoIP. Initially, we describe two subjective methods to collect the dataset for assessing the user's QoE. The subjectively collected dataset is used to investigate the influence of different parameters (e.g. QoS, video types, user profile, etc.) on user satisfaction while using the video services. Later, we propose a client-based HTTP rate adaptive video streaming algorithm over TCP protocol to regulate the user's QoE. The proposed method considers three Quality of Service (QoS) parameters that govern the user perception, which are: Bandwidth, Buffer, and dropped Frame rate (BBF). The BBF method dynamically selects the suitable video quality according to network conditions and user's device properties. Lastly, we propose a QoE driven downlink scheduling method, i.e. QoE Power Escient Method (QEPEM) for LTE-A. It esciently allocates the radio resources, and optimizes the use of User Equipment (UE) power utilizing the Discontinuous Reception (DRX) method in LTE-A

A drastic increase in traffic of mobile broadband is seen in the past few years, which is further accelerated by the increase in usage of smart phones and its applications. The availability of good smart phones and better data connectivity are encouraging mobile users to use video services. This huge increase in usage will pose a lot of challenges to the wireless networks. The wireless network has to become content aware in order to offer enhanced quality of video service through efficient utilization of the wireless spectrum. This thesis focuses on improving the Quality of Experience (QoE) for video transmission over Long Term Evolution (LTE) networks by imparting the content awareness to the system and providing unequal error protection for critical video packets. Two different schemes for the improvement of video quality delivery over LTE networks are presented in this thesis. Using content awareness, the retransmission count of Hybrid Automatic Repeat reQuest (HARQ) are changed dynamically such that the most important video frame gets more number of retransmission attempts, which increases its success for delivery in-turn increasing the received video quality. Since Radio Link Control (RLC) is the link layer for radio interface, the second approach focuses on optimizing this layer for efficient video transmission. As part of this scheme, a new operation mode called Hybrid Mode (HM) for RLC is defined. This mode performs retransmission only for the critical video frames, leaving other frames to unacknowledged transmission. The simulation results of both proposed schemes provide significant improvement in achieving good video quality without affecting the system performance.

With National Telecommunications & Information Administration (NTIA) Advanced Wireless Services (AWS-3) auction of frequencies in the 1695-1710 MHz, 1755-1780MHz, and 2155- 2180MHz bands, users of the Aeronautical Mobile Telemetry (AMT) band from 1755- 1850MHz, known as Upper L-Band, could be greatly affected. This paper takes an initial look at how the 1755-1780MHz band will be used by the cellular carriers and presents some preliminary testing results of adjacent channel (band) interference that could be experienced by AMT users. This paper should be considered as the stepping off point for future interference discussions, required analysis, and further testing.

[EN] In today's information society, there is a growing need to access data communication services ubiquitously, with mobility and increasingly higher data rates. This society's demand has motivated the development of the fourth generation of mobile communications (4G) and its evolution towards the fifth generation (5G). This development has required a revolution on the radio interface of the mobile communications systems, and, consequently, has significantly modified their capabilities and their radio resource management. This is the case of the technology known as Long Term Evolution (LTE) and its 4G version called LTE-Advanced. This Doctoral Thesis addresses the modelling, the radio resource management analysis, and the performance evaluation of the downlink of LTE and LTE-Advanced where, among the different features of LTE-Advanced, the focus is on the Coordinated Multi-Point (CoMP) transmission. The Thesis provides a detailed description of the main characteristics of LTE and LTE-Advanced. The high complexity of these systems, has prompted the use of computer simulations as the primary research methodology. The Thesis makes a detailed description of the simulation methodology and the system modelling required, including some contributions of the author in this field. Among them, it is of significant relevance the link-level simulation results used in the European project WINNER + for the LTE evaluation. With regard to the analysis of the radio resource management in LTE, the fundamentals of link adaptation and scheduling are explained in the first place. In relation to the scheduling, the Thesis includes a thorough study of the proportional fairness concept and the suboptimal implementation typically used in LTE to maximize this metric. This study has resulted in a series of ideas embodied in a modification of the typical implementation, which has proved to be capable of increasing the proportional fairness of the resource allocations. Moreover, the link adaptation analysis has revealed the "flash-light" effect problem, which is characterized by a high interference variability due to rapid changes in the scheduling decisions. The Thesis demonstrates that a particular implementation that stabilizes the scheduling decisions can improve the system performance. The radio resource management analysis of this Thesis is completed with the study of CoMP. Specifically, the CoMP scheme studied in this Thesis is a solution with coordinated scheduling and beamforming (CS/CB), that takes into account realistic and robust assumptions concerning the knowledge that the coordinated points have about the channel state. The Thesis proposes this solution for its simplicity and its ability to improve high data rates coverage and capacity even with incomplete channel knowledge. Concerning LTE and LTE-Advanced evaluation, it is performed in two different types of scenarios. On the one hand, the scenarios defined in the process of evaluation of IMT-Advanced. In this framework, it is evaluated the importance of different multi-antenna techniques, including CoMP, considering full-buffer traffic models. The most important conclusions in these scenarios are the significant performance improvement achieved with spatial multiplexing of users and the fact that CoMP mechanisms provide a reduced benefit. The second group of scenarios are those defined by the European project METIS for the evaluation of 5G technologies. Specifically, an indoor office scenario and an outdoor sports stadium have been selected. In these scenarios, a realistic traffic model is used, and it has been demonstrated the utility of CoMP to satisfy the first 5G requirement definitions with feasible frequency bandwidths. In these scenarios with less homogeneous deployments, or with a limited number of transmitters originating the major part of interference, is where this Thesis has found CoMP to be more useful and where the Thesis promotes its use. / [ES] En la actual sociedad, hay una creciente necesidad de acceso a servicios de comunicación de datos de forma ubicua, móvil y a velocidades cada vez más altas. Esta demanda ha motivado el desarrollo de la cuarta generación de comunicaciones móviles (4G) y su evolución hacia la quinta generación (5G). Este desarrollo ha requerido una revolución en la interfaz radio de los sistemas de comunicaciones móviles modificando en gran medida sus capacidades y la forma en la que se gestionan sus recursos. Este es el caso de la tecnología conocida como Long Term Evolution (LTE) y su versión 4G llamada LTE-Advanced. En concreto, esta Tesis Doctoral aborda el modelado, análisis de la gestión de recursos radio y evaluación de prestaciones del enlace descendente de LTE y LTE-Advanced, donde, de entre las características de LTE-Advanced, se ha puesto el foco de atención en la transmisión multipunto coordinada (CoMP). La Tesis proporciona una descripción detallada de las principales características de LTE y LTE-Advanced. La gran complejidad del sistema descrito ha motivado que la metodología de estudio haya sido la simulación mediante ordenador. La Tesis realiza una descripción detallada de dicha metodología y del modelado del sistema empleado, incluyendo algunas aportaciones del autor en este campo. De entre éstas, destaca la provisión de resultados de simulación de nivel de enlace que se usaron en el proyecto europeo WINNER+ para la evaluación de LTE. En cuanto al análisis de la gestión de recursos radio en LTE, en primer lugar, se explican los fundamentos de la adaptación al enlace y el scheduling. En relación con el scheduling, se realiza un estudio del concepto de proportional fairness y de la implementación subóptima típicamente usada en LTE para maximizar esta métrica. Este estudio ha dado como resultado una modificación de la implementación típica que ha demostrado ser capaz de aumentar la proportional fairness en la asignación de recursos con un bajo incremento de complejidad. Además, el análisis de la adaptación al enlace ha revelado el problema del efecto de "luz de flash" consistente en la alta variabilidad de la interferencia debida a rápidos cambios en las decisiones del scheduler. La Tesis demuestra que se pueden mejorar las prestaciones del sistema estabilizando dichas decisiones mediante una implementación concreta. El bloque de análisis de la gestión de recursos se completa con el estudio de CoMP. Específicamente, se estudia una solución con coordinación de scheduling y conformación de haz (CS/CB) que tiene en cuenta suposiciones reales y robustas en cuanto al conocimiento que los puntos coordinados tienen de los canales radio. La Tesis propone esta solución por su sencillez y capacidad de mejorar la eficiencia de los sistemas de comunicaciones móviles, tanto en cobertura de velocidades altas de transmisión como en capacidad, aun teniendo un conocimiento incompleto del canal. En cuanto a la evaluación de LTE y LTE-Advanced, ésta se realiza en dos tipos de escenarios. Por un lado, los escenarios definidos en el proceso de evaluación de IMT-Advanced. En este marco, se evalúa la importancia de diferentes técnicas de transmisión multiantena, incluyendo CoMP, y considerando tráfico de tipo full-buffer. Se ha obtenido una gran mejora de prestaciones por la multiplexación espacial de usuarios y mejoras discretas por el uso de CoMP. El segundo grupo de escenarios son los definidos por el proyecto europeo METIS para evaluación de tecnologías 5G, concretamente se han elegido un escenario de interiores con una oficina, y uno de exteriores con un estadio deportivo. En estos escenarios se utiliza un tráfico realista y se ha demostrado la utilidad de CoMP para mejorar las prestaciones del sistema. En estos escenarios con despliegues menos uniformes, o con un número limitado de transmisores provocando la mayor parte de la interferencia, es donde esta Tesis ha encontrado la mayor u / [CAT] En l'actual societat de la informació, hi ha una creixent necessitat d'accés a serveis de comunicació de dades de forma ubiqua, mòbil i a velocitats cada vegada més altes. Aquesta demanda de la societat, ha motivat el desenrotllament de la quarta generació de comunicacions mòbils (4G) i la seua evolució cap a la quinta generació (5G). Aquest desenrotllament ha requerit una revolució en la interfície ràdio dels sistemes de comunicacions mòbils i ha modificat en gran manera les seues capacitats i la forma en què es gestionen els seus recursos. Aquest és el cas de la tecnologia coneguda com a Long Term Evolution (LTE) i la seua versió 4G anomenada LTE-Advanced. En concret, aquesta Tesi Doctoral aborda el modelatge, anàlisi de la gestió de recursos ràdio i avaluació de prestacions de l'enllaç descendent de LTE i LTE-Advanced, on, d'entre les característiques de LTE-Advanced, s'ha posat el centre d'atenció en la transmissió multipunt coordinada (CoMP). La Tesi proporciona una descripció detallada de les principals característiques de LTE i LTE-Advanced. La gran complexitat del sistema descrit ha motivat que la metodologia d'estudi s'haja basat en simulació per mitjà d'ordinador. La Tesi realitza una descripció detallada de la metodologia de simulació i del modelatge del sistema empleat, incloent-hi algunes aportacions de l'autor en aquest camp. D'entre aquestes, destaca la provisió de resultats de simulació de nivell d'enllaç que es van usar en el projecte europeu WINNER+ per a l'avaluació de LTE. Pel que fa a l'anàlisi de la gestió de recursos ràdio en LTE, en primer lloc, s'expliquen els fonaments de l'adaptació a l'enllaç i el scheduling. En relació amb el scheduling, es realitza un estudi del concepte de proportional fairness i de la implementació subòptima típicament usada en LTE per a maximitzar aquesta mètrica. L'estudi ha donat com a resultat una modificació de la implementació típica que ha demostrat ser capaç d'augmentar la proportional fairness en l'assignació de recursos amb un baix increment de complexitat. A més, l'anàlisi de l'adaptació a l'enllaç ha desvetllat el problema de l'efecte de "llum de flaix" consistent en la alta variabilitat de la interferència deguda a una ràpida variació de les assignacions de recursos. La Tesi demostra que es poden millorar les prestacions del sistema estabilitzant les decisions del scheduler mitjançant una implementació concreta. En el bloc d'anàlisi de la gestió de recursos d'aquesta Tesi es completa amb l'estudi de CoMP. Específicament, s'estudia una solució amb coordinació de scheduling i conformació de feix (CS/CB), que té en compte suposicions reals i robustes quant al coneixement que els punts coordinats tenen dels canals ràdio dels usuaris servits. La Tesi proposa aquesta solució per la seua senzillesa i capacitat de millorar l'eficiència dels sistemes de comunicacions mòbils, tant en cobertura de velocitats altes de transmissió com en capacitat, encara tenint un coneixement incomplet del canal. Quant a l'avaluació de LTE i LTE-Advanced, aquesta es realitza en dos tipus d'escenaris diferents. D'una banda, els escenaris definits dins del procés d'avaluació de tecnologies IMT-Advanced. Dins d'aquest marc, s'avalua la importància de diferents tècniques de transmissió multi-antena, incloent-hi CoMP, i considerant tràfic de tipus full-buffer. S'ha obtingut una gran millora de prestacions amb la multiplexació espacial d'usuaris i una discreta millora amb CoMP. El segon grup d'escenaris són els definits pel projecte europeu METIS per a l'avaluació de tecnologies 5G, concretament s'han triat un escenari d'interiors amb una oficina, i un d'exteriors amb un estadi esportiu, on s'ha utilitzat un tràfic realista. En aquests escenaris amb desplegaments menys uniformes, o amb un nombre limitat de transmissors provocant la major part de la interferència, és on aquesta Tesi ha trobat la utilitat més gran de / Martín-Sacristán Gandía, D. (2016). 3GPP Long Term Evolution: Performance Analysis and Evolution towards 4G with Coordinated Multi-Point Transmission [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/63261 / TESIS

Pour déployer la quatrième génération de téléphonie 4G/LTE ou « LTE advanced », les opérateurs mobiles sont confrontés à de fortes contraintes : d’une part assurer une bonne couverture géographique mais aussi une excellente qualité de service. Ceci nécessite une ingénierie du réseau qui dépasse largement ce qui a été mis en place pour les réseaux GSM ou 3G. L’industrie des télécoms a créé pour cela le concept de « small cells » ou petites cellules qui viennent en renfort des « macrocells » ou grosses cellules. Cette thèse cherche à apporter une solution à cette problématique à travers notamment le développement d'antennes pour « smart cells ». Cette étude, supportée par le projet FUI NETCOM, doit permettre aux opérateurs d’étendre la couverture et la capacité de leurs réseaux à moindre coût tout en préservant la qualité de service. Pour cela, l’objectif plus précis de cette thèse est de concevoir un système multi-antennaire multistandard MIMO (Multiple-Input Multiple-Output) dédié à des noeuds relais pour le déploiement de la quatrième génération de téléphonie LTE. Cette conception doit être compatible avec 3 bandes de fréquences du LTE : (700-900 MHz) pour les bandes LTE 700 et LTE 800, (1710-1880 MHz) pour les bandes GSM 1800 / LTE 1800 et la dernière (2500-2690 MHz) pour le LTE 2600. Pour cela, nous avons étudié tout d’abord un système à 4 accès mono-bande, en nous concentrant uniquement sur la bande basse de 700 à 900 MHz. Dans une seconde étude, nous avons cherché à couvrir les deux autres bandes supérieures en nous servant d’éléments parasites pour constituer un système MIMO à 4 accès tri-bande. Nous avons ensuite étudié l’influence de l’environnement proche du système antennaire, avec la présence d’un radiateur métallique. Un problème important et fréquent dans les systèmes multi-antennes étant le couplage, nous avons également étudié et réalisé une technique de découplage. Celle-ci servira à isoler les éléments rayonnants à espacement réduit, conçus pour nos trois bandes LTE. / To deploy the fourth generation called 4G/LTE or "LTE advanced", mobile operators face strong constraints: they must ensure a good geographic coverage but also an excellent quality of service. This requires new methods that go far beyond what has been implemented for GSM or 3G networks. The telecom industry has created the concept of "small cells" that reinforce the "macrocells" deployed by the operators. This thesis tries to provide a solution to this problem and more particularly through the development of antennas for a product called "smart cell". This study, supported by the FUI project NETCOM, should enable mobile operators to extend the coverage and capacity of their networks at a lower cost while maintaining a good quality of service. To do that, the aim of this thesis more particularly is the design of a multi-band multi-antennas MIMO system (Multiple-Input Multiple-Output) dedicated to relay nodes for the deployment of the fourth generation 4G/LTE or "LTE advanced". The antenna design considers the coverage of the three LTE operating frequency bands and must be compatible with them. The (700-900 MHz) frequency band is used for the LTE 700 and LTE 800 bands, (1710-1880 MHz) for the GSM 1800/LTE 1800 bands and the last (2500-2690 MHz) for the LTE 2600 bands. In our first study, a reference system with 4 access was studied in simulation and measured, for only the low band 700-900 MHz. In a second study, we tried to cover the other two higher bands to have a tri-band system using the parasitic elements to get a three-band MIMO system with 4 access. We studied then, the influence of the environment close to the antenna system, with the presence of a metallic radiator. As we often encounter a frequent problem in multi-antenna systems which is the coupling problem between the different access of a multi antenna system, so we have studied and realized a decoupling technique. This technique was used to enhance the isolation between the different access.

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.

Thesis concerns with mobile communications theory with focus on data transfer. In the introduction the history, the origin and individual mobile systems generations are described. It is followed by detailed description of second, third and fourth generation mobile systems. Frequency band allocation, signal processing, the system architecture itself, security management and basic features are also discussed. The GSM system is described together with individual data transmission types based on circuit switching – CSD and HSCSD and packet switching – GPRS and EDGE. For UMTS, FDD and TDD modes are listed as well as changes in individual releases, corresponding technologies and provided services. Next, there is the description of LTE and WiMAX systems, together with their improvements whose are part of the fourth generation of mobile systems. Last of the described systems is the still work in progress HAPS, also known as the system of stratospheric platforms. In the end important parameters are summarized and systems are compared with each other.