The global mobile application market is booming in all directions and business giants, viz. Google and Apple, have acknowledged the huge expansion in their Application Market and App Store. There is a demand though for a system that can elevate the momentum of context-aware mobile applications, where an application’s behavior is customized according to context information. This thesis proposes a context-aware system that provides mobile Applications as a Service (AppaaS). AppaaS handles various context information including location information, user profile, device profile, user ratings, and current time to provision the best relevant mobile application to such a context. AppaaS also supports state preservation, where application-specific data that is relevant to a user is stored for future reference. Our prototype demonstrates a seamless system performance with respect to finding relevant applications to a specific context and controlling the applications functions according the users requirements and access privileges. We also demonstrate how AppaaS can preserve an applications state when a user is to reuse the same application again. / Thesis (Master, Computing) -- Queen's University, 2013-01-31 20:23:11.063

Context information is information that describes the user's context. The goal of the Adaptive Context Aware Services (ACAS) project is to enable applications to use context information in order to adapt their behaviour to the user and his environment without requiring the user to manually change/manage parameters. While the concept of linking context aware entities together to form a logical "context network" was introduced earlier in the project, some questions regarding context information discovery and the discovery of context aware entities were previously unanswered. The goal of this thesis was to design and evaluate such a context network allowing entities todiscover each other and exchange information regarding their services and context information. For this purpose, a "Context Entity Registrar" has been developed allowing entities to register, thus they can easily be found by other entities who can query this registrar. During the design of this proposed solution, a special focus has been given to the performance of the registrar, especially how it scales when answering a large number of requests, in order to validate the design's potential as a solution to context aware entity discovery. Measurements have shown that this proposed solution scales well, making it a key element of a context network. Discovery of other entities and of context information play an important role to determine the performances of a context aware implementation. This masters thesis addresses first the issue of the architecture of the context network and then some tests to measure the performances of the proposed solution. / Context information är information som beskriver användarens omgivning. Adaptive Context Aware Services (ACAS) projektet har som mål att möjliggöra applikationer att använda kontext information för att anpassa sitt beteende till användaren och dess miljö, utan att kräva att användaren ska sätta eller hantera alla parametrar manuellt. ACAS projektet har tidigare infört konceptet "context network" som förbinder context aware enheter. Det finns dock kvar några obesvarade frågor angående upptäckt av context information och av context aware enheter.Trots att sättet att länka ihop kontextmedvetna enheter för att forma ett logiskt 'kontext nätverk' introducerades tidigare i projektet, finns det kvar några obesvarade frågor angående upptäckt av kontext information och upptäckt av kontextmedvetna enheter. Examensarbetets mål är att utforma och utvärdera ett sådant kontextnätverk som ger enheterna möjlighet att upptäcka varandra och utbyta information om tjänster och context information. Därför utvecklades "Context Entity Registrar" så att enheterna kan registrera sig för att kunna bli upptäckta av andra enheter som kan göra förfrågningar till detta register. Under designen av denna föreslagna lösning har särskild fokus lagts på registrens prestanda, speciellt avseende skalbarhet med avseende på antalet förfrågningar for att validera designens potential som lösning för kontextmedveten upptäckt av enheter. Mätningar har visat att lösningen skalar bra vilket gör kontext registret till ett nyckelelement i ett kontextnätverk. Upptäkten av andra enheter och av kontextinformation har en viktig roll i att bestämma en kontextmedveten implementations prestanda. Detta examensarbete kommer först att behandla kontextnätverkets arkitektur och därefter några testerna för att mäta prestanda i den föreslagna lösningen.

Today customization of services and applications is one of the major challenges in facilitating ease of use. More and more people are interested in context aware services. In this work, I will study context awareness: What contributions can it make? What technical issues are raised? I will concentrate on the semantic problem and show how new technologies such as a web ontology language can facilitate creating context aware services. An application was implemented using these principles as a proof of concept and to enable some evaluation of this approach. This application has shown that combining semantic processing with SIP call processing is feasible and measurements have demonstrated a highly scalable context aware application for at least simple CPL scripts. / I dagens läge är en av de stora utmaningarna att skräddarsy applikationer och tjänster efter kundens begär för att höja användarvänligheten. Fler och fler kunder intresserar sig för tjänster som är kontextuppmärksamma. Jag kommer i mitt arbete att studera detta, mina frågeställningar är huvudsakligen, hur är detta användbart? Vad slags tekniska problem uppstår kring applikationen av detta koncept? Jag kommer att koncentrera mig på semantiska problem och visa hur nya teknologier så som webbontologispråk kan underlätta då man skapar tjänster som är kontextuppmärksamma. Jag kommer även att skapa en applikation där jag använder dessa principer för att visa konceptet och för att underlätta för en utvärdering av detta tillvägagångssätt. Denna applikation samt mätdata visar att det är möjligt att kombinera semantisk bearbetning och SIP anropsbearbetning för att skapa oerhört robusta applikationer, åtminstonde för enkla CPL script, som är hållbara i ett stort omfång av systemstorlekar.

This Master’s thesis studies different ways of exploiting the signal strength measurements from wireless interfaces for position determination. Difficulties include handling the fluctuating observations and their sensitivity to obstruction. We list important factors to take into account before describing a new system based on location fingerprinting and capable of integrating observations from multiple wireless interfaces. Compared to typical fingerprinting solutions, the training time is an order of magnitude shorter, but the location resolution is limited to locations of particular interest. In an office environment, the proposed solution determines the location correctly 80 percent of the time with sufficient precision for being used with context-aware services. In an open space environment, an incorrect location is reported 42 percent of the time. / Det här exjobbet studerar olika sätt att använda signalstyrka från trådlösa gränssnitt för positionsbestämning. Några av svårigheterna ligger i att hantera observationernas fluktuationer och deras känslighet för obstruktion. De viktigaste faktorerna att ta hänsyn till tas upp innan ett nytt system beskrivs. Det är baserat på positionsigenkänning (location fingerprinting) och kan dra nytta av observationer från flera olika trådlösa gränssnitt. Jämfört med vanliga metoder för positionsigenkänning är träningstiden en storleksordning kortare, men positionsupplösningen är begränsad till ett visst antal positioner av särskilt värde. I en kontorsmiljö klarar den föreslagna lösningen att korrekt bestämma positionen i 80 procent av fallen med tillräckligt hög noggrannhet för att användas till kontextmedvetna tjänster (context-aware services). I en öppen rumslösning ger lösningen en felaktig position i 42 procent av fallen.

Em NGN (Next Generation Networks), os usuários podem se conectar em diferentes tecnologias de rede e desejam, além de uma comunicação transparente, novos serviços personalizados. Neste sentido, este trabalho explora informações de contexto em NGN. O principal objetivo é capturar as informações de contexto envolvidas no momento da utilização da rede sem fio, na escolha do novo ponto de acesso e no procedimento do handover. Este contexto capturado é aplicado para serviços cientes de contexto. A proposta é validada por meio de dois cenários, o primeiro é um mashup que exibe as redes sem fio disponíveis de um determinado local e o segundo um protótipo gerenciador de conexões para atender as preferências do usuário. Adicionalmente, são realizadas duas avaliações do impacto do uso de contexto em handovers. Para tanto, foi implantado um testbed NGN com o protocolo Mobile IP / In the NGN (Next Generation Networks) users can connect their Internet devices to different network technologies. In addition to a seamless communication, users desire new and personalized services. In this sense, this thesis exploits the context-aware information in NGN environments. The main propose is to capture the context information about the time involved by the use of wireless link for selecting the target access point and on the handover procedure. This context information is applied to the context-aware services. The propose is validated through two scenarios: the first is a mashup that shows the availability of wireless networks in a particular location, and the second is a prototype of a connection manager to attend user´s preferences. In addition, two evaluations are accomplished on the impact by the use of context information over handovers. Thus, an NGN testbed is deployed with Mobile IP protocol

Em NGN (Next Generation Networks), os usuários podem se conectar em diferentes tecnologias de rede e desejam, além de uma comunicação transparente, novos serviços personalizados. Neste sentido, este trabalho explora informações de contexto em NGN. O principal objetivo é capturar as informações de contexto envolvidas no momento da utilização da rede sem fio, na escolha do novo ponto de acesso e no procedimento do handover. Este contexto capturado é aplicado para serviços cientes de contexto. A proposta é validada por meio de dois cenários, o primeiro é um mashup que exibe as redes sem fio disponíveis de um determinado local e o segundo um protótipo gerenciador de conexões para atender as preferências do usuário. Adicionalmente, são realizadas duas avaliações do impacto do uso de contexto em handovers. Para tanto, foi implantado um testbed NGN com o protocolo Mobile IP / In the NGN (Next Generation Networks) users can connect their Internet devices to different network technologies. In addition to a seamless communication, users desire new and personalized services. In this sense, this thesis exploits the context-aware information in NGN environments. The main propose is to capture the context information about the time involved by the use of wireless link for selecting the target access point and on the handover procedure. This context information is applied to the context-aware services. The propose is validated through two scenarios: the first is a mashup that shows the availability of wireless networks in a particular location, and the second is a prototype of a connection manager to attend user´s preferences. In addition, two evaluations are accomplished on the impact by the use of context information over handovers. Thus, an NGN testbed is deployed with Mobile IP protocol

A evolução da computação móvel melhora a capacidade de comunicação e colaboração das pessoas. Os principais pilares desta transformação são: o desenvolvimento e produção de dispositivos móveis com capacidade multimídia e equipados com duas ou mais interfaces de rede, a disponibilidade de conectividade sem fio ubíqua e a popularização de aplicações sociais online. As redes sociais online merecem destaque pelas funcionalidades que permitem a criação e compartilhamento de conteúdo digital dentro de círculos sociais, também chamado de mídia social. Serviços na web anexam a localização geográfica do dispositivo ao conteúdo digital, criando as chamadas mídias sociais baseadas em localização. Equipadas com seus telefones e tablets, as pessoas estão criando e consumindo mídias sociais em qualquer lugar. Entretanto, é um desafio manter tais dispositivos móveis conectados nos ambientes de rede sem fio atuais e de próxima geração e.g., múltiplos provedores de acesso e múltiplas tecnologias de comunicação. Pesquisas recentes propõem componentes para o gerenciamento de conectividade sem fio que fazem uso simultâneo do contexto de conectividade atual e de um conjunto destes dados coletados no passado. Tais componentes são preditores de mobilidade, mecanismos de handover ou gerenciadores de mobilidade que utilizam dados de contexto de conectividade de forma particular para atingir seus propósitos. Na presente investigação, propomos uma metodologia que orquestra os principais componentes de gerenciamento de conectividade em um laço retro alimentado. Argumentamos que a coleta de dados de contexto de conectividade pode ser projetada como um sistema de sensoreamento, cujo sensores são as interfaces de rede sem fio. Como parte deste sistema de sensoriamento, os círculos sociais podem assistir o gerenciamento de conectividade compartilhando dados de contexto de conectividade. A ideia central é utilizar serviços baseados em localização para compartilhar dados de contexto de conectividade dentro dos círculos sociais. Desta forma, as redes sociais online adicionam escala para o sistema e permite colaboração em volta de dados de contexto recentes, locais, personalizados e sociais. O objetivo é melhorar experiências de conectividade sem fio e.g., métricas de QoS (Quality of Service) como: vazão, latência e qualidade do sinal. Relatamos como os dados de contexto de conectividade são manipulados com um modelo baseado em grafos e métricas como: intensidade do vértice e grau centralidade. Com isso, identificamos áreas com alta densidade de handovers, definimos a reputação dos usuários e revelamos a cobertura das redes. Resultados de experimentos mostram que a colaboração pode melhorar métricas de QoS de ~18 a ~30% se comparado ao uso de um preditor de mobilidade ou um sistema operacional moderno, respectivamente. Esta discussão se desdobra com foco na viabilidade da solução em termos de sobrecarga de armazenamento e consumo de energia. Os promissores resultados experimentais indicam que nossa solução pode melhorar experiências de conectividade sem fio de usuários móveis / The evolution of mobile computing improves communication and collaboration among people. The main pillars of this transformation are: the development and production of mobile devices with multimedia capabilities and equipped with two or more network interfaces, the availability of ubiquitous wireless connectivity and the popularity of online social applications. Online social networks noteworthy features that allow for the creation and sharing of digital content within social circles, also called textit Social Media. Web Services attach the geographic location of the device to the digital content, creating the so-called textit location-based social media. Equipped with their phones and tablets, people are creating and consuming social media anywhere. However, it is a challenge to keep such mobile devices connected in current and next generation wireless network environments textit e.g., multiple ISPs (Internet Service Provider) and multiple communication technologies. Recent researches proposes components for managing wireless connectivity that make simultaneous use of the current and past connectivity context data. Such components are mobility predictors, handovers mechanisms or mobility managers that use connectivity context data in a particular way to achieve its purposes. In this research, we propose feasiable a methodology that orchestrates the main components of the connectivity management in a feedback loop. We argue that the process of gathering connectivity context data can be designed as a sensing system, whose sensors are wireless network interfaces. As part of this sensing system, the social circles may assist the management of connectivity by sharing connectivity context data. The main idea is to use location-based services to share connectivity context data within social circles. Thus, online social networks add scale to the system and enables collaboration around recent, local, and social context data. The goal is to enhance wireless connectivity experiences in terms of QoS ( textit Quality of Service) metrics textit e.g., throughput, latency and signal quality. We report how this data is handled using complex networks metrics e.g., vertexs strength and centrality degree, to identify high density handover areas, define the mobile users reputation and to reveal the networks coverage. Real experiments showed that collaboration can improve QoS metrics from ~18 to ~30% if compared to just use a mobility predictor or a modern operational system, respectively. The discussion unfolds with focus on the collaborations efficiency as function of time, number of users, discovered area size and mobility patterns. The promising experimental results indicate that our solution can enhance mobile users wireless connectivity experiences

Le concept du « smart » envahit de plus en plus notre vie quotidienne. L’exemple type est sans doute le smartphone. Celui-ci est devenu au fil des ans un appareil incontournable. Bientôt, c’est la ville, la voiture, la maison qui seront « intelligentes ». L’intelligence se manifeste par une capacité d’interaction et de prise de décision entre l’environnement et l’utilisateur. Ceci nécessite des informations sur les changements d’états survenus des deux côtés. Les réseaux de capteurs permettent de collecter ces données, de leur appliquer des pré-traitements et de les transmettre aux applications. Ces réseaux de par certaines de leurs caractéristiques se rapprochent de l’intelligence collective, dans le sens, où des entités de faibles capacités se coordonnent automatiquement, sans intervention humaine, de façon décentralisée et distribuée pour accomplir des tâches complexes. Ces méthodes bio-inspirées ont servi à la résolution de plusieurs problèmes, surtout l’optimisation, ce qui nous a encouragé à étudier la possibilité de les utiliser pour les problèmes liés à l’Ambient Assisted Living ou AAL et à la classification automatique de données. L’AAL est un sous-domaine des services dits basés sur le contexte, et a pour objectifs de faciliter la vie des personnes âgées et handicapées dans leurs défis quotidiens. Pour ce faire, il détermine le contexte et, sur cette base, propose divers services. Deux éléments du contexte nous ont intéressé : le handicap et la position. Bien que la détermination de la position (localisation, positionnement) se fasse à l’extérieur des bâtiments avec des précisions très satisfaisantes, elle rencontre plusieurs difficultés à l’intérieur des bâtiments, liées à la propagation des ondes électromagnétiques dans les milieux difficiles, aux coûts des systèmes, à l’interopérabilité, etc. Nos travaux se sont intéressés au positionnement des personnes handicapées à l’intérieur de bâtiments en utilisant un réseau de capteurs afin de déterminer les caractéristiques de l’onde électromagnétique (puissance, temps, angle) pour estimer la position par méthodes géométriques (triangulation, latération), méthodes de fingerprinting (k plus proches voisins), par des filtres baysiens (filtre de Kalman). L’application est d’offrir des services types AAL tel que la navigation. Nous avons élargi la notion de réseau de capteurs pour prendre en compte tout appareil capable d’émettre et de recevoir une onde électromagnétique et se trouvant dans l’environnement. Nous avons aussi appliqué l’algorithme API sur la classification automatique de données. Enfin, nous avons proposé une architecture à middleware pour la localisation indoor. / The concept of « smart » invades more and more our daily life. A typical example is the smartphone, which becames by years an essential device. Soon, it’s the city, the car and the home which will become « smart ». The intelligence is manifested by the ability for the environment to interact and to take decisons in its relationships with users and other environments. This needs information on state changes occurred on both sides. Sensor networks allow to collect these data, to apply on them some pre-processings and to transmit them. Sensor network, towards some of their caracteristics are closed to Swarm Intelligence in the sense that small entities with reduced capababilities can cooperate automatically, in unattended, decentralised and distributed manner in order to accomplish complex tasks. These bio-inspired methods have served as basis for the resolution of many problems, mostly optimization and this insipired us to apply them on problems met in Ambient Assisted Living and on the data clustering problem. AAL is a sub-field of context-aware services, and its goals are to facilitate the everyday life of elderly and disable people. These systems determine the context and then propose different kind of services. We have used two important elements of the context : the position and the disabilty. Although positioning has very good precision outdoor, it faces many challenges in indoor environments due to the electromagnetic wave propagation in harsh conditions, the cost of systems, interoperabilty, etc. Our works have been involved in positioning disabled people in indoor environment by using wireless sensor network for determining the caracteristics of the electromagnetic wave (signal strenght, time, angle) for estimating the position by geometric methods (triangulation, lateration), fingerprinting methods (k-nearest neighbours), baysiens filters (Kalman filter). The application is to offer AAL services like navigation. Therefore we extend the definition of sensor node to take into account any device, in the environment, capable of emiting and receiving a signal. Also, we have studied the possibility of using Pachycondylla Apicalis for data clustering and for indoor localization by casting this last problem as data clustering problem. Finally we have proposed a system based on a middleware architecture.

A evolução da computação móvel melhora a capacidade de comunicação e colaboração das pessoas. Os principais pilares desta transformação são: o desenvolvimento e produção de dispositivos móveis com capacidade multimídia e equipados com duas ou mais interfaces de rede, a disponibilidade de conectividade sem fio ubíqua e a popularização de aplicações sociais online. As redes sociais online merecem destaque pelas funcionalidades que permitem a criação e compartilhamento de conteúdo digital dentro de círculos sociais, também chamado de mídia social. Serviços na web anexam a localização geográfica do dispositivo ao conteúdo digital, criando as chamadas mídias sociais baseadas em localização. Equipadas com seus telefones e tablets, as pessoas estão criando e consumindo mídias sociais em qualquer lugar. Entretanto, é um desafio manter tais dispositivos móveis conectados nos ambientes de rede sem fio atuais e de próxima geração e.g., múltiplos provedores de acesso e múltiplas tecnologias de comunicação. Pesquisas recentes propõem componentes para o gerenciamento de conectividade sem fio que fazem uso simultâneo do contexto de conectividade atual e de um conjunto destes dados coletados no passado. Tais componentes são preditores de mobilidade, mecanismos de handover ou gerenciadores de mobilidade que utilizam dados de contexto de conectividade de forma particular para atingir seus propósitos. Na presente investigação, propomos uma metodologia que orquestra os principais componentes de gerenciamento de conectividade em um laço retro alimentado. Argumentamos que a coleta de dados de contexto de conectividade pode ser projetada como um sistema de sensoreamento, cujo sensores são as interfaces de rede sem fio. Como parte deste sistema de sensoriamento, os círculos sociais podem assistir o gerenciamento de conectividade compartilhando dados de contexto de conectividade. A ideia central é utilizar serviços baseados em localização para compartilhar dados de contexto de conectividade dentro dos círculos sociais. Desta forma, as redes sociais online adicionam escala para o sistema e permite colaboração em volta de dados de contexto recentes, locais, personalizados e sociais. O objetivo é melhorar experiências de conectividade sem fio e.g., métricas de QoS (Quality of Service) como: vazão, latência e qualidade do sinal. Relatamos como os dados de contexto de conectividade são manipulados com um modelo baseado em grafos e métricas como: intensidade do vértice e grau centralidade. Com isso, identificamos áreas com alta densidade de handovers, definimos a reputação dos usuários e revelamos a cobertura das redes. Resultados de experimentos mostram que a colaboração pode melhorar métricas de QoS de ~18 a ~30% se comparado ao uso de um preditor de mobilidade ou um sistema operacional moderno, respectivamente. Esta discussão se desdobra com foco na viabilidade da solução em termos de sobrecarga de armazenamento e consumo de energia. Os promissores resultados experimentais indicam que nossa solução pode melhorar experiências de conectividade sem fio de usuários móveis / The evolution of mobile computing improves communication and collaboration among people. The main pillars of this transformation are: the development and production of mobile devices with multimedia capabilities and equipped with two or more network interfaces, the availability of ubiquitous wireless connectivity and the popularity of online social applications. Online social networks noteworthy features that allow for the creation and sharing of digital content within social circles, also called textit Social Media. Web Services attach the geographic location of the device to the digital content, creating the so-called textit location-based social media. Equipped with their phones and tablets, people are creating and consuming social media anywhere. However, it is a challenge to keep such mobile devices connected in current and next generation wireless network environments textit e.g., multiple ISPs (Internet Service Provider) and multiple communication technologies. Recent researches proposes components for managing wireless connectivity that make simultaneous use of the current and past connectivity context data. Such components are mobility predictors, handovers mechanisms or mobility managers that use connectivity context data in a particular way to achieve its purposes. In this research, we propose feasiable a methodology that orchestrates the main components of the connectivity management in a feedback loop. We argue that the process of gathering connectivity context data can be designed as a sensing system, whose sensors are wireless network interfaces. As part of this sensing system, the social circles may assist the management of connectivity by sharing connectivity context data. The main idea is to use location-based services to share connectivity context data within social circles. Thus, online social networks add scale to the system and enables collaboration around recent, local, and social context data. The goal is to enhance wireless connectivity experiences in terms of QoS ( textit Quality of Service) metrics textit e.g., throughput, latency and signal quality. We report how this data is handled using complex networks metrics e.g., vertexs strength and centrality degree, to identify high density handover areas, define the mobile users reputation and to reveal the networks coverage. Real experiments showed that collaboration can improve QoS metrics from ~18 to ~30% if compared to just use a mobility predictor or a modern operational system, respectively. The discussion unfolds with focus on the collaborations efficiency as function of time, number of users, discovered area size and mobility patterns. The promising experimental results indicate that our solution can enhance mobile users wireless connectivity experiences

Modern Web or ¿Eternal-Beta¿ applications necessitate a flexible and easy-to-use data management platform that allows the evolutionary development of databases and applications. The classical approach of relational database systems following strictly the ACID properties has to be extended by an extensible and easy-to-use persistency layer with specialized DB features. Using the underlying concept of Software as a Service (SaaS) also enables an economic advantage based on the ¿economy of the scale¿, where application and system environments only need to be provided once but can be used by thousands of users. Within this tutorial, we are looking at the current state-of-the-art from different perspectives. We outline foundations and techniques to build database services based on the SaaS-paradigm. We discuss requirements from a programming perspective, show different dimensions in the context of consistency and reliability, and also describe different non-functional properties under the umbrella of Service-Level agreements (SLA).