[pt] Nas últimas décadas, tem-se observado um crescente interesse nas tecnologias relacionadas a ambientes de comunicação móvel sem fio. Em grande parte, esse interesse vem acompanhando o crescimento do mercado de telecomunicações, mais especificamente dos sistemas de telefonia móvel celular. Os usuários vêm absorvendo rapidamente essas tecnologias, originando novas necessidades, como a utilização de serviços de dados multimídia, que exige garantias de qualidade. Nesse contexto, um dos desafios encontrados é conseguir a utilização eficiente do limitado espectro de freqüências disponível, fornecendo serviços com qualidade para os usuários. Esta dissertação propõe uma arquitetura para provisão de qualidade de serviço -QoS- fim-a-fim em redes móveis sem fio, levando em consideração características inerentes a esses ambientes. Para alcançar esse objetivo, são propostas modificações aos frameworks para provisão de QoS em ambientes genéricos de processamento e comunicação, visando atender às necessidades trazidas pelas redes móveis, gerando uma arquitetura adaptável para fornecer QoS em ambientes que ofereçam suporte à mobilidade. Uma instanciação dos frameworks para provisão de QoS em redes móveis sem fio é descrita através de um cenário de mobilidade, no qual é simulada uma rede infraestruturada de serviços integrados funcionando sobre o IP Móvel, de modo a validar a peoposta. / [en] In the last decades, increasing interest has been observed in technologies related to wireless mobile communication environments. Great part of such interest follows the growth in the telecommunications industry, more specifically of cellular mobile telephony systems. Users are quickly absorbing these technologies and generating new necessities, such as the use of services of multimedia data, which demand quality assurance. In this context, one of the challenges is the efficient use of the limited frequency spectrum available, providing users quality services. This thesis proposes an architecture for the provision of end-to-end QoS in wireless mobile networks, taking into account inherent characteristics of these environments. To reach this purpose, modifications were proposed to the frameworks for QoS provisioning in generic processing and communication environments, aiming to fulfill the necessities brought by mobile networks, generating an adaptable architecture to offer QoS in environments that support mobile connections. In order to validate the proposal, an instantiation of frameworks for QoS provisioning in wireless mobile networks is described by means of a mobility scenario in which an infrastructure network of integrated services is simulated working over Mobile IP.

Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2018-04-12T13:49:50Z No. of bitstreams: 1 Deborah Luisa Detânico Vieira_.pdf: 1504339 bytes, checksum: 49a2adc770aff79d216c818e22dea099 (MD5) / Made available in DSpace on 2018-04-12T13:49:50Z (GMT). No. of bitstreams: 1 Deborah Luisa Detânico Vieira_.pdf: 1504339 bytes, checksum: 49a2adc770aff79d216c818e22dea099 (MD5) Previous issue date: 2017-05-17 / Nenhuma / Com a crescente demanda de serviços de voz e, principalmente, dados móveis se fez necessário o desenvolvimento das tecnologias de quarta geração (4G). O padrão Long Term Evolution (LTE), desenvolvido pela Third Generation Partnership Project (3GPP), foi escolhido pela International Telecommunications Union (ITU) como tecnologia para atender os requisitos da quarta geração de serviços móveis. Para as operadoras inserirem esta nova tecnologia em suas redes existentes, se faz necessário um estudo meticuloso de planejamento, muito embora, na prática, este planejamento seja desenvolvido de forma empírica. O problema de planejamento de redes é conhecido e bem estudado no ramo da computação, conhecido como problema de recobrimento de conjuntos e classificado, pela sua complexidade, como NP-difícil. Dadas as características diferenciadas da arquitetura da rede do LTE, este trabalho busca resolver o problema de planejamento de redes de quarta geração (4G), utilizando uma modelagem matemática aplicada a uma metaheurística híbrida, composta de Algoritmo Genético e Busca Tabu. Almejase resolver o problema de cobertura de uma determinada região, cobrindo a maior área possível com o menor número possível de Base Stations (BS), visando ao planejamento com maior assertividade e redução do custo de implantação da rede 4G. / With the constantly demand of voice services and mostly in mobile data, there was the need the development of the mobile services of fourth generation (4G). The pattern Long Term Evolution, developed by the Third Generation Partnership Project (3GPP) was chosen by the International Telecommunications Union (ITU) as technology to attend the requirements of the fourth generation of mobile services. For the mobile operators introduce and apply this new generation in their own existing networks, they need to do an extensive research and planning, even if, in practical means, it is applied using the empirical way. The network planning problem is widely known and studied in computing area as set-covering problem ans classified as NPhard. Due the unique characteristics of network architecture of LTE, this work aims to solve the mobile’s fourth generation planning problem using a mathematics modelling apply to a hybrid metaheuristics, composed with Genetic Algorithm and Tabu Search. It aims solve the coverage problem of a specific region, covering the largest area possible with the fewest number of Base Sations (BS) possible, seeking the best compliance and cost reduction of the LTE network deployment.

La sécurité des systèmes de communication mobiles/sans fil est problématique, car ceux-ci sont généralement construits suivant une topologie répartie ou arborescente. Les noeuds qui composent ces réseaux sont caractérisés par des ressources limitées et connectés généralement entre eux d'une manière ad-hoc sans l'aide d'une tierce personne de confiance. Les méthodes de sécurité matures issues du monde des réseaux filaires s'appuient souvent sur des procédés nécessitant des systèmes centralisés et des ressources importantes qui sont difficiles à mettre en place dans des réseaux à fortes contraintes. Dans le cadre de cette thèse, on propose de nouvelles solutions de sécurité qui exploitent les propriétés du médium électromagnétique et de l'interface de radiocommunication dans le but d'assurer des communications sécurisées. La thèse est structurée en deux parties. La première est dédiée au problème de génération de clés de cryptage en exploitant les propriétés des systèmes de communication à bande de fréquence ultra large (ULB). Trois phases sont nécessaires pour convertir le canal radio en clés secrètes: l'estimation du canal, la quantification et l'accord mutuel entre noeuds. Des expérimentations ont été effectuées pour valider les hypothèses sur lesquelles se fondent les méthodes de génération de clés (c.-à-d. la réciprocité et la décorrélation spatiale du canal). Notre étude a montré que la robustesse de ces techniques de sécurité repose sur le choix des algorithmes de numérisation utilisés pour la conversion de la signature du canal ULB vers un format de clé. Une solution adaptative d'extraction a été proposée, évaluée et testée. La robustesse contre les attaques de prédiction du canal a été également examinée. La deuxième partie traite le problème des intrusions illégitimes aux réseaux sans fil. Dans un premier temps, nous testons expérimentalement une méthode basée sur les variations électromagnétiques afin de détecter l'attaque d'écoute passive "eavesdropping" dans les réseaux de capteurs. Par la suite, nous présentons nos travaux concernant l'attaque relais qui est une variante de l'attaque de l'homme-du-milieu et qui est considérée comme un grand défi en particulier pour les systèmes d'authentification. Une nouvelle approche basée sur la détection de la variation des caractéristiques du bruit a été proposée. Des études théoriques et expérimentales ont été conduites pour vérifier la validité de la proposition dans les systèmes de communication de type RFID. / Security in mobile wireless networks is considered a major impediment since these environments are a collection of low-cost devices. They are generally collected in ad hoc manner without the help of trusted third party. Therefore, conventional security methods are always inappropriate. Recent contributions propose to explore the radio communication interface and to turn the radio propagation problems into advantages by providing new alternatives to enhance security. In this thesis, we investigate the signal-based security concept and study its effectiveness through experiments. The first part of this dissertation discusses the problem of key generation from Ultra Wide Band channel. To derive secret keys from channel measurements three stages are required: channel estimation, quantization and key agreement. A campaign of measurements has been performed to confirm the fundamental channel requirements for key generation (i.e., the reciprocity and the spatial decorrelation). Results show that the robustness of such techniques depends on the channel information used as source of randomness as well as on the underlying algorithms. Analysis on the impact of each stage (i.e. the quantization and the key agreement) on the security has been presented. An adaptive key extraction method is proposed, performances are evaluated and robustness against deterministic channel prediction attacks is presented. The second part of the dissertation considers the problem of intrusion detection. First, we test a method based on electromagnetic radiation to discover the presence of an adversary in the receiver/emitter vicinity. Then, the problem of relay attack detection is investigated in RFID systems. A relay attack is a man-in-the middle attack, where the adversary is able to successfully pass the authentication phase by relaying messages between the legitimate verifier and the prover. A new solution based on the noise channel is proposed to detect this attack. Experimental and theoretical results are provided to test the effectiveness of the new proposition.

With increasing demands on network reliability and speed, network suppliers need to effectivize their communications algorithms. Frequency measurements are a core part of mobile network communications, increasing their effectiveness would increase the effectiveness of many network processes such as handovers, load balancing, and carrier aggregation. This study examines the possibility of using supervised learning to predict the signal of inter-frequency measurements by investigating various learning algorithms and pre-processing techniques. We found that random forests have the highest predictive performance on this data set, at 90.7\% accuracy. In addition, we have shown that undersampling and varying the discriminator are effective techniques for increasing the performance on the positive class on frequencies where the negative class is prevalent. Finally, we present hybrid algorithms in which the learning algorithm for each model depends on attributes of the training data set. These algorithms perform at a much higher efficiency in terms of memory and run-time without heavily sacrificing predictive performance.

Made available in DSpace on 2016-06-02T19:06:08Z (GMT). No. of bitstreams: 1 5463.pdf: 18006027 bytes, checksum: 047b84b38eb03b475dacbf51b7bf50b1 (MD5) Previous issue date: 2013-07-31 / Financiadora de Estudos e Projetos / Vehicular ad-hoc networks (VANETs) are networks capable of establishing communications between vehicles and road-side units. VANETs could be employed in data transmission applications. However, due to vehicle mobility, VANETs present intermittent connectivity, making message transmission a challenging task. Due to the lack of an end-to-end connectivity, messages are forwarded from vehicle to vehicle and stored when it is not possible to retransmit. Additionally, in order to improve delivery probability, messages are replicated and disseminated over the network. However, message replication may cause high network overhead and resource usage. As result, considerable research e_ort has been devoted to develop algorithms for speci_c scenarios: low, moderate and high connectivity. Nevertheless, algorithms projected for scenarios with a speci_c connectivity lack the ability to adapt to situations with zones presenting diferent node density. This lack of adaptation may negatively a_ect the performance in application such as data transmission in cities. This masters project proposes develops a method to automatically adapt message replication routing algorithms to diferent node density scenarios. The proposed method is composed of three phases. The first phase collects data from message retransmission events using a standard routing algorithms. The second phase consists in training a decision tree classifier based on the collected data. Finally, in the third phase the trained classifier is used to determine whether a message should be retransmitted or not based on the local node density. Therefore, the proposed method allows routing algorithms to query the trained classifier to decide if a message should be retransmitted. The proposed method was evaluated with real movement traces in order to improve Spray and Wait and Epidemic routing algorithms. Results indicate that the proposed method may contribute to performance enhancement. / As VANETs são redes de veículos com capacidade de estabelecer comunicações sem fio entre veículos e com equipamentos nas estradas. Estas redes poderiam ser usadas para a transferência de dados de diversas aplicações. No entanto, devido á mobilidade dos veículos, as VANETs apresentam conectividade intermitente entre os nós, dificultando a transmissão de mensagens. Ante a impossibilidade de ter conectividade de fim a fim, as mensagens são encaminhadas progressivamente de veículo em veículo, e armazenadas quando não houver a possibilidade de retransmitir. Adicionalmente, para incrementar a probabilidade de entrega, as mensagens são replicadas e disseminadas pela rede. Não obstante, a replicação de mensagens pode gerar alta sobrecarga de rede e alto consumo de recursos. Por causa disto, projetaram-se algoritmos para cenários específicos de: baixa, moderada e alta conectividade. Estes algoritmos, quando aplicados em ambientes de zonas de diferente densidade de nós,como cidades, podem diminuir o seu desempenho pela falta da capacidade de se adaptar a diferentes condições de conectividade. Contudo, neste trabalho foi desenvolvido um método para adaptar o comportamento dos algoritmos de roteamento por replicação de mensagens a diferentes situações de conectividade segundo a densidade das zonas onde se movimentam os nós retransmissores. O método consiste em três fases. Na primeira, são coletados os dados dos eventos de repasse de mensagens utilizando o algoritmo de roteamento padrão. Na segunda fase, utilizam-se os dados coletados para treinar um classificador baseado em _arvores de decisão. Na _ultima fase, o classificador é então empregado para determinar se uma situação de repasse de mensagem _e favorável segundo a densidade de nós. Desta forma, os algoritmos de roteamento podem decidir se repassar ou não uma mensagem com o suporte do classificador. Esta abordagem foi avaliada com traces de movimentos reais, para aprimorar o desempenho dos algoritmos de roteamento Spray and Wait e Epidemic. Os resultados dos experimentos realizados revelam que esta abordagem pode contribuir para o aprimoramento do desempenho.

Cette thèse se positionne dans le cadre de l'algorithmique distribuée tolérante aux pannes adaptée aux réseaux mobiles à grande échelle.L'auto-stabilisation est une approche de tolérance aux pannes satisfaisante dans les systèmes ayant des perturbations transitoires, mais pas dans les réseaux très dynamiques à grande échelle. La faute est due à l'éventuelle absence totale de service lorsque les perturbations sont fréquentes.Pour remédier à cet inconvénient, nous avons introduit l'approche auto-stabilisation robuste apportant une garantie de service pendant la phase de stabilisation.La garantie de service offerte par l'auto-stabilisation robuste est assurée via : (1) le délai de reprise d'un service minimum, et(2) la préservation du service minimum pendant la convergence vers un service optimum en dépit de l'occurrence de certaines perturbations hautement tolérées.L'intérêt d'avoir la propriété auto-stabilisation robuste est d'assurer une haute disponibilité du système en dépit de l'occurrence des perturbations et changements topologiques.Dans cette thèse, nous proposons, prouvons et évaluons une suite protocolaire auto-stabilisante robuste.Dans un premier temps, nous proposons deux protocoles auto-stabilisants robustes pour les problèmes de partitionnement, et l'établissement et le maintien de la connaissance des clusters voisins.Les deux protocoles sont écrits dans le modèle à états et fonctionnent sous l'hypothèse d'un démon distribué faiblement équitable.Le protocole de partitionnement, baptisé R-BSC, permet de partitionner le réseau en clusters à 1-saut. Les noeuds choisis pour être leaders sont les plus aptes à ce rôle, et les clusters construits sont de taille bornée dans le but d'équilibrer la charge entre leaders.Le protocole R-BSC fournit rapidement, en 4 rounds seulement, un service minimum où le réseau est complètement partitionné en clusters de taille bornée.Pendant la convergence vers un service optimum, où les leaders seront bien les noeuds les plus aptes et leur nombre sera réduit localement, le service minimum restera préservé. Le protocole de connaissance des clusters voisins, baptisé R-CNK, permet à chaque leader de connaître l'identité des leaders des clusters voisins, les chemins menant vers eux, ainsi que la composition (liste des noeuds ordinaires) des clusters voisins.Le service minimum de notre protocole R-CNK, atteint après 4 rounds seulement, garantit que tout leader connaît toujours des chemins vers tous les leaders des clusters voisins. Ce service minimum est maintenu en dépit des changements de la structure hiérarchique : création / destruction des clusters, changement de composition des clusters suite au départ / arrivé des noeuds ordinaires.Un deuxième aspect de nos travaux concerne l'évaluation des protocoles conçus (R-BSC et R-CNK) dans le contexte des réseaux mobiles.Nous avons mené une étude expérimentale sous le simulateur NS2 pour évaluer les performances de nos protocoles, ainsi que ceux des protocoles auto-stabilisants correspondants.Cette étude a montré que nos protocoles R-BSC et R-CNK offrent de meilleurs performances en terme de garantie de service, d'où l'efficacité de l'approche auto-stabilisation robuste par rapport à l'auto-stabilisation classique. / This dissertation is focused on fault-tolerant distributed algorithms adapted to large scale mobile networks.Self-stabilization is a fault-tolerance approach suited for systems with transient disruptions, but not for large scale dynamic networks.The fault is due to the eventual total lack of service when faults occur frequently.To address this drawback, we have introduced the robust self-stabilization approach that improves the service guarantee during the stabilization phase.The service guarantee provided by the robust self-stabilization is achieved via:(1) fast recovery to a minimum service and(2) preservation of minimum service during the convergence to an optimum service despite the occurrence of highly tolerated disruptions.Having the robust self-stabilization property ensures a high availability of the system despite the occurrence disruptions and topological changes in the network.In this thesis, we propose, evaluate and prove a series of robust self-stabilizing protocols.At first, we propose two robust self-stabilizing protocols for both problems : clustering and the maintain of knowledge about neighbor clusters.The two protocols are written in the local shared memory model and operate under the assumption of a weakly fair distributed daemon.The clustering protocol, called R-BSC, gathers the network nodes into 1-hop clusters.It allows a best choice of leaders, and it builds clusters with limited size in order to balance the load between leaders.The protocol R-BSC quickly provides, after at most 4 rounds, a minimum service where the network is completely partitioned into bounded-size clusters.During the convergence towards an optimum service, in which leaders will be the most appropriate nodes and their number will be reduced locally, the minimum service is preserved.The protocol for knowledge of neighbor clusters, called R-CNK, allows each leader to know the identity of leaders of neighbor clusters, paths leading to them, and the composition (list of ordinary nodes) of its neighbor clusters.The minimum service provided by of R-CNK protocol, reached after 4 rounds, ensures that every leader always knows paths towards all the leaders of neighbor clusters.We conducted an experimental study using the simulator NS2 to evaluate and to compare the performance of our protocols (R-BSC and R-CNK) with those of their self-stabilizing version in the context of mobile networks.This study confirmed that our protocols R-BSC and R-CNK offer a better service guarantee.

Depuis les années 90, la technologie réseau et radio mobile a fait l'objet de progrès phénoménaux. Cette avancée technologique s'est faite en parallèle du côté réseau, du côté application et du coté besoin de l’utilisateur. L’évolution rapide de la technologie a eu pour conséquence l’existence d’un environnement hétérogène où la couverture est assurée par la coexistence de plusieurs types de réseaux. Le défi soulevé par cette architecture est de pouvoir naviguer entre plusieurs réseaux d’une façon transparente. La navigation entre réseaux de types différents est connue sous le nom du Handover vertical. Le standard IEEE 802.21 offre une composante appelée Media Independent Handover (MIH) qui contient une fonction capable de transmettre l’état des liens du nœud mobile depuis les couches inférieures vers les couches supérieures. MIH s’intercale entre le niveau 2 et le niveau 3 dans la pile protocolaire. Le rôle principal de MIH est d’aider le nœud mobile à faire un transfert sans coupure entre des réseaux de types différents, mais la logique de sélection est laissée sans implémentation.Dans ce contexte nous avons travaillé sur l’amélioration de la gestion du Handover en proposant une nouvelle architecture appelée VHMC et basée sur MIH offrant des nouvelles méthodes de sélection du réseau destination. La première proposition est un nouvel algorithme nommé Multiple Criteria Selection Algorithm (MCSA) basé sur plusieurs paramètres de qualité du service. Nous avons utilisé le simulateur Network Simulator (NS2) pour évaluer nos propositions en étudiant le nombre de paquets perdus et le temps de latence du Handover durant la période du transfert. La deuxième contribution est un nouveau modèle de sélection du réseau destination basé sur la technique de la logique floue. La base d’inférence, qui est l’élément central de la décision de ce modèle, est déduit grâce à une étude basée sur un nombre élevé de cas de Handover réels collectés des serveurs de la compagnie de télécommunication libanaise "Alfa". Une troisième solution est proposée à travers un nouveau modèle de sélection du réseau destination basé sur la théorie de la régression linéaire multiple. / Since 1990, networking and mobile technologies have made a phenomenal unprecedented progress. This progress has been experienced on multiple fronts in parallel; especially on the application level and the user's needs one. This rapid evolution of the technology imposed a need for the existence of heterogeneous environments where the coverage is ensured throughout the different available networks. The challenge with such architecture would be to provide the user with the ability to navigate through the different available networks in a transparent and seamless fashion. However, the navigation among different types of networks is commonly referred to as vertical Handover. The IEEE 802.21 standard offers a component that is called Media Independent Handover (MIH) which has a function that provides the capability of transmitting the state of the connection of the mobile nodes from the lower to upper layers. This layer would exist between layer 2 and layer 3 within the protocol architecture. The main role of MIH is to help the mobile node transfer without interrupt among different types of networks, but the logic of selection is left without implementation. In this context, we worked on the improvement of the Handover management by proposing a new architecture, called VHMC and based on MIH by offering new methods for selecting the destination network. The first solution is a new algorithm called Multiple Criteria Selection Algorithm (MCSA) based on multiple parameters of the quality of service. We used Network Simulator (NS2) for testing our approach and study the number of lost packets and lost time during Handover. The second solution is a new model for selecting the destination network based on fuzzy logic techniques. The distinctive characteristic of this model lies in the study of genuine Handover records taken from a Lebanese mobile operator called "Alfa". A third proposed solution for network selection is based on multiple linear regression theory.

Depuis plusieurs années, bénéficiant de nombreuses évolutions technologiques, le domaine de l'instrumentation sans fil a conquis de nouveaux champs d'application, comme le suivi de paramètres physiologiques des personnes, par le développement des réseaux de capteurs sans fil autour du corps humain (BAN, pour Body Area Networks). Majoritairement orienté vers le domaine médical et l'amélioration des conditions de vie des patients, ce type de plate-forme s'est plus récemment étendu à d'autres activités, notamment aux loisirs et au sport. Selon le contexte applicatif, les hypothèses et les contraintes liées à ces réseaux peuvent être très variées, c'est pourquoi le développement de mécanismes de communication adaptés est nécessaire. Au cours de mes travaux de thèse, je me suis intéressé à la réalisation de plate-formes de collecte de données pour des applications sportives en situation de mobilité. Dans une première partie est abordée la collecte d'informations individuelles, pour laquelle nous présentons une preuve de concept en contexte sportif, avant d'apporter des éléments complémentaires à la modélisation des canaux des BAN et aux stratégies de communication pour la collecte individuelle. Ensuite, nous abordons la réflexion sur la collecte d'informations dans les réseaux denses et mobiles, en proposant des algorithmes distribués basés sur le consensus permettant d'identifier des groupes de façon dynamique, à petite et large échelle. Des réalisations pratiques à chaque étape de mes travaux de thèse permettent la validation des plate-formes développées, grâce à un ensemble conséquent de données collectées sur le terrain. L'analyse des données fournit également des éléments pour mieux caractériser les communications, notamment à large échelle, ce qui ouvre de nombreuses pistes quant à de futurs travaux. De plus, si un fort contexte applicatif est présent dans ces travaux, les méthodes d'analyse et les algorithmes développés sont valorisables et extensibles à d'autres domaines. / The technological evolutions which have taken place for the last decades allowed the emergence of new application fields, such as the wireless monitoring of physiological parameters collected on the human body, with the development of Wireless Body Area Networks (WBANs, or BANs). Mostly dedicated to the medical domain and the improvement of the patients' comfort and safety, this kind of platforms more recently extended to other kinds of activities, such as sports and leisures. According to the applicative context, the hypotheses and constraints associated to these networks can vary drastically, yielding the necessity of developing adapted communication mechanisms. The works presented in this thesis have focused on the realization of data collection platforms for mobile sports applications. In a first part, we concentrate on the individual data collection, for which we give a proof of concept in the context of a Marathon race, before aiming at a better understanding of individual channel models and cooperative mechanisms for on-body data centralization. In a second part, we are interested in dense and mobile networks consisting in an important number of coexisting BANs. Our aim is to propose distributed algorithms based on consensus to allow dynamic group detection, with a variable scale. The validation of the approaches developed in this document is performed by practical implementations and experiments at each step of this work, thanks to an important amount of real world collected data. Through extended analyzes, we provide elements allowing to characterize the communication within mobile BANs, and particularly large scale networks. Although guided by the strong applicative context of live TV broadcast, these works and analysis methods don't lose in generality, and this challenging and original context opens a lot of perspectives.

Abstract Energy efficiency is a powerful measure for promoting sustainability in technological evolution and ensuring feasible battery life of end-user devices in mobile computing. Peer-to-peer technology provides decentralized and self-organizing architecture for distributing content between devices in networks that scale up almost infinitely. However, peer-to-peer networking may require lots of resources from peer nodes, which in turn may lead to increased energy consumption on mobile devices. For this reason, peer-to-peer networking has so far been considered unfeasible for mobile environment. This thesis makes several contributions towards enabling energy-aware peer-to-peer networking in mobile environments. First, an empirical study is conducted to understand the energy consumption characteristics of radio interfaces and typical composition of traffic in structured peer-to-peer networks. This is done in order to identify the most essential obstacles for utilizing peer-to-peer technology in mobile environments. Second, the e-Aware model for estimating the energy consumption of a mobile device is developed and empirically verified to achieve 3-21% error in comparison to real-life measurements. Third, the e-Mon model for the energy-aware load monitoring of peer nodes is developed and demonstrated to improve the battery life of mobile peer nodes up to 470%. Fourth, the ADHT concept of mobile agent based virtual peers is proposed for sharing the peer responsibilities between peer nodes in a subnet so that they can participate in a peer-to-peer overlay without compromising their battery life. The results give valuable insight into implementing energy-efficient peer-to-peer systems in mobile environments. The e-Aware energy consumption model accelerates the development of energy-efficient networking solutions by reducing the need for time-consuming iterations between system development and evaluations with real-life networks and devices. The e-Mon load monitoring model facilitates the participation of battery-powered devices in peer-to-peer and other distributed networks by enabling energy-aware load balancing where energy-critical mobile nodes carry less load than other nodes. The ADHT facilitates the participation of constrained-capacity wireless devices, such as machine-to-machine nodes, in a peer-to-peer network by allowing them to sleep for most of their time. / Tiivistelmä Energiatehokkuus on kustannustehokas tapa vähentää päätelaitteiden käytön aiheuttamia kasvihuonepäästöjä sekä parantaa niiden akunkestoa. Vertaisverkkoteknologia tarjoaa hajautetun, itseorganisoituvan, sekä lähes rajattomasti skaalautuvan verkkoarkkitehtuurin päätelaitteiden väliseen tallennustilan, mediasisältöjen ja tietoliikennekapasiteetin suorajakamiseen. Vertaisverkkojen suurin heikkous mobiilikäytön näkökulmasta on niiden päätelaitteille aiheuttama ylimääräinen kuormitus, mikä näkyy lisääntyneenä energiankulutuksena. Tässä väitöskirjassa on tutkittu mekanismeja vertaisverkon päätelaitteiden energiatehokkuuden parantamiseksi, tavoitteena riittävä akunkesto mobiilikäytössä. Aluksi työssä tutkittiin empiirisesti langattomien verkkojen mobiilipäätelaitteille aiheuttamaa energiankulutusta sekä rakenteellisten vertaisverkkojen vertaispäätelaitteille aiheuttamaa liikennekuormitusta. Tavoitteena oli muodostaa käsitys suurimmista haasteista mobiililaitteiden käytölle vertaisverkoissa. Seuraavaksi mobiiliverkkojen energiankulutusta koskevasta havaintoaineistosta muodostettiin energiankulutusmalli, e-Aware, jolla voitiin arvioida mobiilipäätelaitteen energiankulutusta erilaisilla verkon liikenneprofiileilla. Mallilla saavutettiin parhaimmillaan kolmen prosentin keskimääräinen virhe. Kolmannessa vaiheessa kehitettiin energiatietoinen kuormanseurantamalli, e-Mon, jota käyttäen saavutettiin jopa 470 % lisäys mobiilin vertaispäätelaitteen akunkestoon. Viimeisessä vaiheessa kehitettiin ADHT-konsepti, joka on uudentyyppinen tapa jakaa vertaispäätelaitteiden kuormaa usean saman verkkoklusterin päätelaitteen kesken käyttäen laitteesta toiseen kiertävää mobiiliagenttia. Väitöskirjan tulokset osoittavat että mobiililaitteiden energiatehokkuutta vertaisverkoissa pystytään olennaisesti parantamaan energiatietoisia kuormanjakomekanismeja käyttäen. Työssä kehitetty e-Aware nopeuttaa energiatehokkaiden hajautettujen järjestelmien kehitystyötä tarjoamalla tehokkaan työkalun järjestelmän energiankulutuksen arvioimiseen jo kehitysvaiheessa. e-Mon mahdollistaa energiatietoisen kuormanjaon vertaisverkoissa tarjoamalla tarvittavan kuormanseurantamallin. ADHT puolestaan tarjoaa uudenlaisen tavan vähentää vertaisverkkojen aiheuttamaa päätelaitekuormitusta hyödyntäen maksimaalisesti rajoitetun kapasiteetin laitteiden unitilojen käyttöön perustuvaa energiankulutusoptimointia.

Depuis quelques années le trafic de l'internet mobile ne cesse d'augmenter. Cette croissance soutenue est liée à plusieurs facteurs, parmi lesquels l'évolution des terminaux, la grande diversité des services et des applications disponibles et le déploiement des nouvelles technologies d'accès radio mobile (3G/4G). À cet égard, le standard 3GPP pour les réseaux LTE propose une architecture offrant une gestion fine de la QoS (par flux). Ce modèle, hérité des réseaux mobiles traditionnels orientés connexion, soulève des problèmes en termes de scalabilité, efficacité et performances. Les travaux entrepris dans cette thèse ont pour objectif principal de proposer des solutions plus simples et moins coûteuses pour la gestion de la QoS dans les réseaux mobiles. À cette fin, à l'issue d'une étude et de l'évaluation de l'impact de la signalisation associée au modèle de QoS standard, deux modèles alternatifs ont été proposés. Nous proposons tout d'abord un modèle basée sur les mécanismes IP inspiré de l'approche DiffServ (par agrégat) largement étudié dans les réseaux IP fixes. Ce modèle fournit une gestion de la QoS simple, efficiente et rentable, tout en garantissant des performances équivalentes au modèle standard. Cependant, elle nécessite une remise à niveau de tous les eNB, et donc une longue phase de transition. En conséquence, nous proposons SloMo qui vise à améliorer l'expérience des clients mobiles, mais avec un objectif de déploiement plus rapide. SloMo est une solution de gestion implicite de la QoS depuis un point unique situé sur le chemin des communications. SloMo exploite la dynamique instaurée par le mécanisme de contrôle de flux de TCP. Il vise à recréer un goulot d'étranglement dynamique dans un équipement contrôlé par l'opérateur lorsque les points de congestion réels ne sont pas accessibles. Une fois ce goulot d'étranglement déporté, il est alors aisé d'effectuer une gestion de la qualité IP classique dans l'équipement supportant Slo-Mo. / The mobile data landscape is changing rapidly and mobile operators are today facing the daunting challenge of providing cheap and valuable services to ever more demanding customers. As a consequence, cost reduction is actively sought by operators as well as Quality of Service (QoS) preservation. Current 3GPP standards for LTE/EPC networks offer a fine tuning QoS (per-flow level), which inherits many characteristics of legacy telco networks. In spite of its good performance, such a QoS model reveals costly and cumbersome and finally, it remains very rarely deployed, thereby giving way to basic best-effort hegemony. This thesis aims at improving QoS in mobile networks through cost-effective solutions; To this end, after an evaluation of the impact and cost of signaling associated with the standard QoS model, alternative schemes are proposed, such as the IP-centric QoS model (per aggregate) inspired from the DiffServ approach widely used in fixed IP networks. This model provides a simple, efficient and cost-effective IP level QoS management with a performance level similar to standardized solutions. However, as it requires enhancements in the eNB, this scheme cannot be expected in mobile networks before a rather long time.Thus, we introduce Slo-Mo, which is a lightweight implicit mechanism for managing QoS from a distant point when the congestion point (e.g. eNB) is not able to do it. Slo-Mo creates a self-adaptive bottleneck which adjusts dynamically to the available resources taking advantage of TCP native flow control. Straightforward QoS management at IP level is then performed in the Slo-Mo node, leading to enhanced customer experience at a marginal cost and short term.