During the past few years, Power Line Communications (PLC) have become a popular connectivity solution to answer the growing need of home networks for bandwidth. As wireless technologies, this solution spares the user from cabling its Local Area Network (LAN), by directly using the home power grid as a transmission medium. While PLC generally offer a larger coverage than Wireless Local Area Networks (WLAN), the capacity offered by current systems is not sufficient to simultaneously support bandwidth intensive streams. In this thesis, we aim at exploring various solutions for future PLC networks. Firstly, we aim at improving the spectral efficiency of the current systems' Physical (PHY) layer, where two modulation schemes are compared. On the one hand, we study the modulation deployed in current PLC networks, called windowed Orthogonal requency Division Multiplexing (OFDM), and we highlight the main limitation of this solution in the particular context of PLC. On the other hand, we show that and alternative solution, called OFDM/Offset Quadrature Amplitude Modulation (OQAM), offers some degrees of freedom which could highly benefit to PLC networks. Secondly, the study is oriented toward the Media Access Control (MAC) layer of PLC systems, considering a multiuser utilization of the network. In this second part, we aim at proposing allocation solutions that will allow a more efficient utilization of the limited and shared transmission resource. We firstly study the opportunity of defining an Orthogonal Frequency-Division Multiple Access (OFDMA) transmission scheme for point-to-multipoint transmissions, in order to increase data rates by taking advantage of the diversity between users' channels. Finally, the last Chapter is dedicated to the study of broadcast and multicast communications in PLC networks, where we show that a smart aggregation of the set of users to reach could greatly improve efficiency of multicast transmissions.

Ces dernières années, la technologie des courants porteurs en ligne (CPL) a fait son apparition dans les réseaux domestiques afin de répondre au besoin grandissant de bande passante. Comme pour les solutions sans-fil, cette technologie présente l’avantage de ne pas nécessiter le déploiement de nouveaux câbles à l’intérieur de la maison, en utilisant directement le réseau électrique comme milieu de transmission. Offrant une zone de couverture plus importante que les réseaux Wi-Fi, les débits offerts par les équipements actuels ne sont néanmoins pas suffisants pour supporter simultanément des applications gourmandes en bande passante. Cette thèse vise donc à explorer différentes solutions pour les futurs réseaux domestiques basés sur cette technologie. L’étude a d’abord été menée au niveau de la couche Physique des systèmes, où deux solutions de transmission ont été comparées. D’un côté, la modulation windowed OFDM, déployée dans la grande majorité des réseaux actuels, est étudiée afin de mettre en avant ses limites dans le contexte particulier des réseaux sur courant porteur. Dans cette partie, nous montrons concrètement le gain en capacité que pourrait apporter une modulation alternative, l’OFDM/OQAM, présentant des degrés de liberté supplémentaires vis-à-vis de l’OFDM classique, et dont l’exploitation s’avère particulièrement intéressante pour cette étude. Dans un second temps, la problématique de la couche MAC a été abordée dans le contexte d’une utilisation multi-usager du réseau. L’objectif de cette seconde partie a été de proposer des solutions nouvelles pour l’allocation et le partage de la ressource entre les différents utilisateurs du réseau. Premièrement, nous étudions la possibilité de définir un nouveau mode d’accès, basé sur l’OFDMA, permettant de tirer efficacement parti de la diversité entre différents canaux de transmission, afin d’augmenter significativement les débits pour les transmissions point-à- multipoint. Enfin, le dernier chapitre aborde le problème de la transmission multicast inhérent aux réseaux PLC actuels, en proposant une méthode d’agrégation des utilisateurs résultant en une augmentation significative des débits. / During the past few years, Power Line Communications (PLC) have become a popular connectivity solution to answer the growing need of home networks for bandwidth. As wireless technologies, this solution spares the user from cabling its Local Area Network (LAN), by directly using the home power grid as a transmission medium. While PLC generally offer a larger coverage than Wireless Local Area Networks (WLAN), the capacity offered by current systems is not sufficient to simultaneously support bandwidth intensive streams. In this thesis, we aim at exploring various solutions for future PLC networks. Firstly, we aim at improving the spectral efficiency of the current systems’ Physical (PHY) layer, where two modulation schemes are compared. On the one hand, we study the modulation deployed in current PLC networks, called windowed Orthogonal requency Division Multiplexing (OFDM), and we highlight the main limitation of this solution in the particular context of PLC. On the other hand, we show that and alternative solution, called OFDM/Offset Quadrature Amplitude Modulation (OQAM), offers some degrees of freedom which could highly benefit to PLC networks. Secondly, the study is oriented toward the Media Access Control (MAC) layer of PLC systems, considering a multiuser utilization of the network. In this second part, we aim at proposing allocation solutions that will allow a more efficient utilization of the limited and shared transmission resource. We firstly study the opportunity of defining an Orthogonal Frequency-Division Multiple Access (OFDMA) transmission scheme for point-to-multipoint transmissions, in order to increase data rates by taking advantage of the diversity between users’ channels. Finally, the last Chapter is dedicated to the study of broadcast and multicast communications in PLC networks, where we show that a smart aggregation of the set of users to reach could greatly improve efficiency of multicast transmissions.

Made available in DSpace on 2016-06-02T19:05:46Z (GMT). No. of bitstreams: 1 3258.pdf: 1305335 bytes, checksum: c4e30eacc66435b8a91b867024dc5550 (MD5) Previous issue date: 2010-04-30 / Financiadora de Estudos e Projetos / This work proposes and evaluates an architecture to support ubiquitous applications in digital TV-centric home networks. The computational power and support for communication with other devices in home networks, incorporated by digital TV, create new possibilities and opportunities for research and promote the development of new types of services and applications. Currently, a significant amount of computational devices is part of human environment, however, the interaction with these devices, depends frequently on some process of learning due to differences found in interfaces and ways to configure and operate each one. Potential applications may use the TV set for interaction with domestic appliances, as the TV has a central role in many people's daily entertainment. It seems natural and relevant that functionalities of digital TV sets may be used to develop an architecture to support applications that require intercommunication between devices, with the aim of making transparent and accessible in several places of a residence the services offered by domestic appliances. The proposed architecture consists of a protocol layer for automatic discovery of devices and a new set of services whose aim is to facilitate the implementation of ubiquitous applications in home network that has the TV as a central element of interaction with other devices. HoNeS (Home Network Services) is the name of the architecture presented in this work. For the design and implementation of HoNeS, technologies for digital TV environments and home networking were investigated, beyond its current state of the art. As a proof of concept, the proposed services were effectively implemented. The set of protocols Universal Plug and Play (UPnP) was chosen for automatic discovery and control of devices, and Ginga, the middleware of the Brazilian digital TV system, used as digital TV environment. / Este trabalho propõe e avalia uma arquitetura para o suporte de aplicações ubíquas em redes domésticas centradas em TV digital. O ganho computacional e o suporte à comunicação com outros dispositivos em ambientes residenciais, incorporados pela TV digital, criam novas possibilidades e oportunidades de pesquisa e permitem o desenvolvimento de novos tipos de serviços e aplicações. Atualmente, uma quantidade significativa de dispositivos computacionais faz parte de nosso ambiente, entretanto, a interação com esses dispositivos, na maioria das vezes, depende de algum processo de aprendizagem devido às diferentes interfaces e formas de configuração e operação de cada um. Potenciais aplicações podem usar o aparelho de TV como meio para interações com dispositivos domésticos, já que a TV exerce um papel central no entretenimento cotidiano de muitas pessoas. Parece natural e relevante que suas funcionalidades possam ser utilizadas em uma arquitetura para o suporte a aplicações que demandem intercomunicação entre dispositivos, visando tornar transparente e acessível em diversos lugares da residência os serviços oferecidos pelos dispositivos domésticos. A arquitetura é composta por uma camada de protocolo de descoberta automática de dispositivos e por um conjunto de novos serviços cujo objetivo é facilitar a implementação de aplicações ubíquas em redes domésticas que possui a TV como elemento central de interação com outros dispositivos. HoNeS (Home Network Services) é o nome da arquitetura apresentada neste trabalho. Para a concepção e implementação do HoNeS, foram investigadas tecnologias para ambientes de TV digital e redes domésticas, além do seu atual estado da arte. Como prova de conceito, os serviços propostos na arquitetura foram efetivamente implementados. O conjunto de protocolos Universal Plug and Play (UPnP) foi escolhido para implementação da descoberta automática e controle de dispositivos; e o middleware Ginga utilizado como ambiente de TV digital.