L'accès à Internet par satellite permet de connecter des régions isolées de la terre ou des utilisateurs en mouvement, pour lesquels une solution terrestre peut s’avérer couteuse voire impossible. L’utilisation de constellations de satellite en orbite basse permet de transmettre avec des délais similaires à ceux des transmissions terrestres, permettant l’utilisation des protocoles de transport classiques comme TCP. L’utilisation d’un tel environnement engendre cependant des contraintes spécifiques à ce type de réseau, comme des délais de transmission variables et un important taux d’erreur, principalement lors de la traversée de l’atmosphère. Pour compenser ces forts taux de pertes, des mécanismes de fiabilisation doivent être introduit au niveau des couche basse. Ces mécanismes ont toutefois un impact négatif sur les performances des protocoles de transport, notamment TCP, limitant grandement le débit. Le but de cette thèse est de comprendre dans un premier temps les interactions entre les mécanismes de fiabilisation et les protocoles de transport, pour ensuite proposer des solutions permettant d’améliorer la qualité des transmissions. / LEO satellite constellations allow to connect isolated or mobile users to the Internet, when terrestrial solutions are too expensive or impossible to deploy. Using such constellations allow to connect these areas with transmission delays close to terrestrial delays, and then to use the classic transport protocols such as TCP. However, this environment brings new impairments such as variable delays and important error rate between the satellite and the ground receiver. To counteract this high error rate, reliability schemes are introduced on the link between the satellite and the ground user. However, these schemes have a negative impact on the transport protocol (TCP), mitigating the throughput, and which has not been deeply studied yet. In this thesis, we first understand the impact of the reliability schemes on the transport layer, and then propose solutions to improve the efficiency of the transmissions.

L’objectif de cette thèse empirique est de contribuer à une meilleure compréhension du marché de la téléphonie mobile en étudiant les stratégies d’offres (et notamment la tarification) des opérateurs, ainsi que les comportements des consommateurs en termes d’usages et de recommandation. / We wish to contribute to the understanding of the mobile market by studying the pricing strategies of the operators, but also by studying the consumers behavior in terms of uses and recommendation.

L’Homme est aujourd’hui au centre d’une sphère électronique composée de terminaux hétérogènes capables d’offrir des services similaires. Il choisit désormais l’interface adaptée à ses besoins, passant librement d’un terminal à un autre pour bénéficier d’un même service. Cette liberté induit de nouvelles problématiques de mobilité ayant un impact direct sur l’expérience utilisateur. L’état de l’art fait apparaître deux catégories de services aux caractéristiques propres : des services applicatifs revêtant diverses formes (applications locales et distantes) et des services de télécommunications reposant sur des infrastructures standardisées. L’étude des contraintes de mobilité et des approches existantes révèle que les solutions actuelles dans ce domaine sont incomplètes et ne peuvent assurer une continuité de bout en bout : désignation, transfert, adaptation, etc. Nous avons implémenté des mécanismes de continuité dans les environnements ims et web pour des services de télécommunications et multimédias afin de mettre en évidence les lacunes des solutions existantes, et identifier les fonctions élémentaires d’une gestion globale de la mobilité. Le résultat de ces travaux révèle qu’une approche plus abstraite du concept de service est nécessaire dans la définition d’un modèle générique de continuité adapté au milieu hétérogène de l’utilisateur. Nous avons introduit de nouveaux concepts et des mécanismes de mobilité originaux que nous avons ensuite implémentés dans un "distributed Service Manager". Enfin nous avons évalué ce modèle grâce à des tests qualitatifs et quantitatifs sur un prototype selon un scénario de transfert d’un service d’édition de texte dans un milieu hétérogène. Les résultats particulièrement satisfaisants prouvent la faisabilité de notre solution et son adéquation avec les contraintes de continuités temporelle et contextuelle / People now live within an electronic sphere of heterogenous devices providing similar services. From now on they can freely choose the best interface corresponding to their needs, switching from a device to another while enjoying a same service. This freedom leverage new mobility issues that directly impact the user experience. The state of the art introduces two services types with specific properties : applicative services commonly known as local or remote applications and telecommunication services based on standardised infrastructures. The study of the mobility constraints and the existing approaches shows that current solutions in this domain are incomplete and cannot assure an end-to-end continuity : selection, transfer, adaptation, etc. We implemented continuity mechanisms in the ims and web environments for telecommunication and multimedia services in order to emphasize the lacks of the existing solutions and identify the basic features of a unified mobility management model. These works led to a more abstract vision of the service concept, required to define a generic continuity model adapted to the user’s heterogeneous environment. We introduced innovative concepts and original mobility mechanisms, which we implemented in a "distributed Service Manager". Finally, we evaluated this model with qualitative and quantitative tests on a prototype according to a transfer scenario of text-edition service in a heterogeneous environment. Results are very satisfying, they prove the feasibility of our solution and its adequacy with the temporal and contextual constraints

Due to the increasing digitization of society, Gamification of services has become increasingly proliferated. Identifying and knowing how to manipulate the factors for successful implementation of gamification strategies is paramount. This study focuses on the factors of intrinsic motivation as identified by Self-Determination Theory while utilizing the principles of Service-Dominant Logic. Though the relationship between Self-Determination Theory and Gamification is relatively well researched, this is the first study to examine the relationship between all of these three distinct theories. This is a deductive quantitative study wherein upon an extensive theoretical and literature chapter, a collection of survey questions was devised and disseminated to appropriate audiences. This approach yielded 108 survey answers which were designed to examine independent versus dependent variables in order to draw a conclusion on specific relationships. The research findings revealed that the combination of Self-Determination Theory and Service-Dominant Logic did not yield any significant benefits when attempting to enhance customer motivation. Consequently, this study failed to provide evidence supporting the notion that these theories, when employed collectively within a gamification context, could produce more positive outcomes in comparison to Self-Determination Theory alone. The study yielded some interesting implications. Managers must exercise caution regarding the adverse effects that excessive customer autonomy can have. They should strive to establish a well-defined equilibrium between granting customers control while still meeting their expectations. Moreover, managers must tactfully avoid making customers feel inadequate which can be done through offering manageable challenges and tailoring products and services to suit their unique requirements. Lastly, managers should account for the preferences of their target audience when implementing gamification and allocate resources to research and development to remain informed about the latest advancements in this field.

[pt] A telefonia celular no Brasil representa um segmento de notável sucesso comercial nos últimos anos, apresentando um crescimento muito rápido e uma penetração que superou em muito as melhores expectativas das próprias operadoras. Parte importante deste sucesso é devido à adoção da telefonia celular pelas camadas de menor renda da população. Considerando este contexto, esta pesquisa tem como objetivo estudar os impactos da telefonia celular para este segmento, levantando as motivações para uso do serviço, os impactos no dia-a-dia dos usuários e o processo de aprendizado e uso dos serviços disponíveis. A pesquisa foi feita por intermédio de entrevistas em profundidade com usuários de baixa renda familiar per capita. Como resultado, notamos que a telefonia celular contribuiu para uma melhoria na qualidade de vida, pelas oportunidades de relacionamento social e inserção no mercado de trabalho. Por outro lado, nota-se uma oportunidade em potencializar o uso do telefone celular entre os usuários de baixa renda, simplificando seu uso e divulgando as vantagens dos serviços disponíveis. / [en] During the last years, mobile telecommunication has been a segment with remarkable commercial success in Brazil, presenting a fast user base growth and a market penetration that exceeded the best expectations from the own operators. A significant part of this success is due to the adoption of cell phone by lower income users. Considering this context, this research aims to study the impacts of mobile telecommunication for this specific segment, by depicting the motivations for its usage, the impacts on user´s daily life and how they learned and use available services. Based on extensive interviews with lower median family income users, the research indicates that the cell phone can help improve life quality, through social integration and greater work opportunities. On the other hand, we can note an opportunity to improve cell phone usage among lower income users, by simplifying and divulgating the benefits of existing services.

In this study the technology acceptance model (TAM) serves as the foundation to analyze the behavior of consumers with regards to their use of the smartphone and its associated services. The research also aims to provide a basis for companies that need a complete theoretical framework to better understand the behavior of consumers using smartphones and related services under the intensely competitive environment and constantly evolving changes in consumer demand. The extensive version of TAM will assist in analyzing consumer behavior and influences affecting the use of smartphones, which will be validated through the empirical data collected. This research utilizes one questionnaire to conduct investigations pertaining to the study. Questionnaires were distributed to consumers that use mobile services and/or applications. The majority of the questionnaires were filled out by students in college and graduate institutions in Taipei, Taiwan. In addition, a majority of the subjects who participated have already purchased smartphones. A total of 500 questionnaires were distributed and 266 were returned, making a 53.2 % return rate. Results retrieved from this study are as follows: 1. When a user experiences deeper social presence, higher subjective norms are created by the application. 2. When a user experiences deeper social presence, perceived usefulness of the application increases. 3. When a user experiences deeper social presence, perceived ease of use of the application fluctuates. 4. The higher the application’s subjective norms are, the more significant is the increase of the user’s image. 5. The higher the application’s subjective norms are, the more significant is the increase of perceived usefulness 6. As the user’s perceived ease of use of the application increases, the greater the influence becomes on perceived usefulness. 7. The higher the application’s subjective norm is, the more the user’s behavioral intention to use increases. 8. As the application’s perceived usefulness increases, the user’s behavioral intention to use the application also increases. 9. As the user’s perceived ease of use for the application increases, the greater the influence on behavioral intention to use becomes. Undoubtedly, companies need to understand consumer behavior and their use of the smartphones. Consequently, this study seeks to use theories from TAM as a basis and consider principles of external factors influencing a consumer-----social presence and society’s influences. The components of TAM, social presence and society’s influences are analyzed to compile this research.

Der E-Government-Fortschritt wird nach wie vor durch redundante Entwicklungsaktivitäten und isolierte, wenig interoperable Lösungen gehemmt. Die Herausforderung liegt weniger in der Entwicklung und Einführung leistungsstarker Informationssysteme, sondern in der Verbreitung bestehender Lösungen. Die Arbeit identifiziert mögliche Strategien für den Transfer von E-Government-Lösungen zwischen Verwaltungen gleicher wie auch verschiedener föderaler Ebene. Es werden Konzepte zur Diffusion von Innovationen, zum Technologie- wie auch Politiktransfer herangezogen. Weiter werden drei umfangreiche Fallstudien vorgestellt. Sie führen zu transferhemmenden wie auch fördernden Faktoren und somit zu Gestaltungsoptionen für erfolgreiche Transferprozesse unter den vielfältigen Rahmenbedingungen im öffentlichen Sektor. / The research work on transfer strategies explores ways to spread e-government solutions among public administrations. Studies about diffusion of innovations, technology transfer and policy transfer are used. The work is based on outcomes of three case studies, which lead to obstacles and promoters of transfer processes and hence to design options for successful transfers at diverse conditions within public sector in Germany.

Privacy is a strategic issue so that much attention has been constantly devoted to information privacy in response to competitive pressure in dynamic marketplace, particularly in the trend of e-business settings. Ubiquitous services (u-services) are recognized as the logical extension of e-/m-services because they can be initiated by e- and further propagated by m-services (Junglas & Watson 2006). In u-services context, customers are always connected seamlessly in context-awareness networks so the higher degree of customized and personalized services can be timely served. Likewise, customers may also well be aware of privacy threats behind that. Consequently, privacy issues are identified as a key hindrance for booming u-services. While a large body of studies focusing on privacy issues have examined relevant factors influence customer decision making such as customer beliefs (i.e. trust and risk), privacy concerns, the representations of privacy statement, and even the privacy calculus, this study aims to explore a theoretical proactive privacy practice model (PPPM) as a guideline for an e-services provider (ESP) initiating its privacy practices to its customers to enhance voluntary information disclosure. Drawing upon integrative social contracts theory, the proposed PPPM embraced technical and non-technical elements such as human, legal, and economic relevant perspectives, that is, e-services providers¡¦ proactive privacy governance, and customer perceived value and competitive strategies for u-services. An empirical survey was conducted in a B2C e-services context to examine the relationships among these constructs. The results indicate that there are significant relationships between those three antecedents and disclosure willingness respectively. Meanwhile, the moderating effect of competitive strategies significantly and positively associates with proactive privacy governance and disclosure willingness. These findings not only broaden current knowledge of the disclosure behavior but also allow ESPs to strategically manage privacy and leverage privacy protection for a competitive advantage and identify the strengths and weaknesses of their current privacy mechanisms, guiding them to develop more proactive and prominent privacy practices for extending their businesses to future u-services or u-businesses.

This research investigates the European Mobile Telecommunications industry, looking at the biggest strategic challenges Mobile Operators are going to face in the next years. Mobile Services platforms represent the most important paradigm in the industry. Companies as Apple, Google and Facebook have successfully married new consumer devices and Internet platforms with a variety of online services and content undermining Operators ́ central role in the value network. This scenario highlights the importance to investigate how Operators can adopt successful strategies to keep on playing a meaningful role in the Mobile Services domain.These strategies are identifies and mapped adopting a value network model for the Mobile Services domain. This model is the main contribution of this research, tracking new ways of cooperating among them. Operators ́ strategies revolve around two main drivers: defeating networks congestion (investing in network upgrade, optimization & spectrum auctions, charging Service Providers for HQ delivery services and elaborating data price plans for mobile customers) and finding new revenue opportunities (working with Service Providers to offer Location-based services, offering charging services to interested parties and working on Mobile Services platforms).As first step, the investigation offers an overview over the industry, looking at static (actors, technologies, services, devices, end-users and value network configuration) as well as dynamic (trends as Open Mobile, MVNOs, Fixed-Mobile Convergence and Substitution and 4G adoption) aspects. Then the research continues analyzing Mobile Services platforms, proposing an interesting approach to classify scientific articles about this topic. Italy is analyzed as case study and subsequently the model is developed. To conclude the study deals with some reflections about the delicate topic of shaping strategies after a massive usage of end-users data to provide innovative and sophisticated mobile services.

La croissance des appareils connectés, principalement due au grand nombre de déploiements de l'internet des objets et à l'émergence des services de cloud mobile, introduit de nouveaux défis pour la conception d'architectures de services dans le Cloud Computing Mobile (CCM) du cloud computing mobile. Nous montrons dans cette thèse comment l'architecture orientée services SOA peut être une solution clé pour fournir des services cloud mobiles distribués et comment la plate-forme OSGi peut être un cadre adaptatif et efficace pour fournir une telle implémentation. Nous adaptons le cadre CCM proposé à différents contextes d'architecture. Le premier est un modèle centré traditionnel, où les appareils mobiles sont réduits à consommer des services. Le second est un modèle distribué où la puissance de l'interaction de mobile à mobile offre des opportunités illimitées de services de valeur, et enfin, l'architecture à trois niveaux est considérée avec l'introduction de la notion de cloudlet. Pour chaque contexte, nous explorons la performance de notre cadre axé sur le service et le comparons à d'autres solutions existantes. / The growth of connected devices, mostly due to the large number of internet of things IoT deployments and the emergence of mobile cloud services, introduces new challenges for the design of service architectures in mobile cloud computing MCC. An MCC framework should provide elasticity and scalability in a distributed and dynamic way while dealing with limited environment resources and variable mobile contexts web applications, real-time, enterprise services, mobile to mobile, hostile environment, etc. that may include additional constraints impacting the design foundation of cloud services. We show in this thesis how service-oriented architecture SOA can be a key solution to provide distributed mobile cloud services and how OSGi platform can be an adaptive and efficient framework to provide such implementation. We adapt the proposed MCC framework to different architecture contexts. The first one is a traditional centric model, where mobile devices are reduced to consuming services. The second one is a distributed model where the power of mobile-to-mobile interaction offers unlimited value-services opportunities, and finally, three-tier architecture is considered with the introduction of the cloudlet notion. For each context, we explore the performance of our service-oriented framework, and contrast it with alternative existing solutions.