This thesis explores possibilities of using recently introduced ensemble-based component models (represented by the DEECo model) as a management layer in a cloudlet-like environment for mobile computation offloading, which can lead to savings of limited mobile-specific resources such as battery life. As a part of the solution, the goal is analyzed, possible issues and problems are identified and then addressed by designing and implementing a reference architecture for computation offloading of parts of mobile applications managed by a DEECo-based control layer. The implementation is presented in the form of an offloading framework, whose use is demonstrated on two applications for the Android platform. Finally, the framework's performance and utility is evaluated by comparing offloaded and local executions of the same application. Powered by TCPDF (www.tcpdf.org)

Avec l’avènement du nomadisme, des périphériques mobiles, de la virtualisation et du Cloud Computing ces dernières années, de nouvelles problématiques sont nées aux vues des considérations écologiques, de la gestion d’énergie, de la qualité de service, des normes sécuritaires et bien d’autres aspects liés à nos sociétés. Pour apporter une solution à ces problèmes, nous avons défini la notion de Cloudlet tel un Cloud local où peuvent se virtualiser des périphériques et ses applications embarquées. Ensuite, nous avons conçu une architecture distribuée basée sur ce pattern d’architecture lié au Cloud Computing et à la virtualisation de ressources. Ces définitions permettent de placer notre travail par rapport aux autres approches de déportation d’applications mobiles.D’autre part, un réseau de Cloudlets permet la protection de l’activité effectuée sur un périphérique mobile par la déportation d’applications embarquées dans une machine virtuelle s’exécutant dans la Cloudlet, ainsi que le suivi des usagers dans leur déplacement.Ces définitions nous ont guidées dans l’écriture de spécifications formelles via une algèbre de processus d’ordre supérieure. Elles autorisent le calcul de la sémantique opérationnelle pour les différentes études de cas basées sur ce concept de Cloudlet. Ces spécifications ont permis de décrire une nouvelle vision de la composition des périphériques virtuels applicables à tous les périphériques, les capteurs ou les actuateurs. L’ensemble des équations obtenues constitue une définition formelle de référence non seulement pour le prototypage d’une Cloudlet mais aussi pour la construction des automates temporisés.En se basant sur la structure de nos spécifications, nous avons construit un modèle d’automates temporisés pour un réseau de Cloudlets. Par l’emploi de technique de model checking, nous avons établi des propriétés temporelles montrant que toute exécution d’une application mobile sur un périphérique mobile pouvait être déportée dans une Cloudlet sous condition d’une structure applicative. Ces travaux ont abouti à des choix techniques donnant lieu à un prototype d’une telle architecture distribuée par l’emploi de serveurs OSGi. D’une part, nous fournissons une architecture logicielle d’application mobile. D’autre part, nous mettons en œuvre le principe de migration vers une Cloudlet voisine et son retour. Ces résultats sont une validation de nos choix initiaux et attestent de la réalité de nos travaux. Ils autorisent la prise de mesure permettant de définir le coût d’une migration vers une Cloudlet pendant une exécution, ainsi que son suivi au cours du déplacement de l’usager / With the advent of nomadism, mobile devices, virtualization and cloud computing in recent years, new problems have arisen taking into account ecological concerns, energy management, quality of service, security standards and many other aspects related to our societies. To solve these problems, we define the concept of Cloudlet as a local cloud where virtual devices and embedded applications can be virtualized. Then, we design a distributed architecture based on this architectural pattern related to cloud computing and virtualization of resources. These notions allow us to position our work among other approaches to offload mobile applications in a Cloudlet.On the other hand, a network of Cloudlets helps to secure the activity carried out on a mobile device by offloading embedded applications in a running virtual machine in the Cloudlet, and also to monitor users during their movements.These definitions guided us towards writing formal specifications via a higher order processes of algebra. They facilitate the calculation of operational semantics for different case studies based on this Cloudlet concept. These specifications foster a new vision for designing virtual devices suitable to all devices, sensors or actuators. This set of equations constitutes a formal definition relevant not only for prototyping a Cloudlet but also for constructing a timed automata system.Following the structure of our specifications, we built a model of timed automata for a network of Cloudlets. Exploiting the model checking techniques, we have established temporal properties showing that any execution of a mobile application on a mobile device could be offloaded in a Cloudlet depending on a given software architecture. This work resulted in making technical choices leading to a prototype of such a distributed architecture using an OSGi server. A first result leads us to define a software architecture for mobile applications. Secondly, we implement the principle of migration to a Cloudlet neighbor. Our tests validate our initial choices and confirm the hypotheses of our work. They allow taking measures in order to assess the cost of an offloading to a Cloudlet during runtime, as well as keeping track during user’s movements

Handheld devices are becoming increasingly common, and they have varied range of resources. Mobile Cloud Computing (MCC) allows resource constrained devices to offload computation and use storage capacities of more resourceful surrogate machines. This enables creation of new and interesting applications for all devices. We propose a scheme that constructs a high-performance de-centralized system by a group of volunteer mobile devices which come together to form a resourceful unit (cloudlet). The idea is to design a model to operate as a public-resource between mobile devices in close geographical proximity. This cloudlet can provide larger storage capability and can be used as a computational resource by other devices in the network. The system needs to watch the movement of the participating nodes and restructure the topology if some nodes that are providing support to the cloudlet fail or move out of the network. In this work, we discuss the need of the system, our goals and design issues in building a scalable and reconfigurable system. We achieve this by leveraging the concept of virtual dominating set to create an overlay in the broads of the network and distribute the responsibilities in hosting a cloudlet server. We propose an architecture for such a system and develop algorithms that are requited for its operation. We map the resources available in the network by first scoring each device individually, and then gathering these scores to determine suitable candidate cloudlet nodes. We have simulated cloudlet functionalities for several scenarios and show that our approach is viable alternative for many applications such as sharing GPS, crowd sourcing, natural language processing, etc.

Handheld devices are becoming increasingly common, and they have varied range of resources. Mobile Cloud Computing (MCC) allows resource constrained devices to offload computation and use storage capacities of more resourceful surrogate machines. This enables creation of new and interesting applications for all devices. We propose a scheme that constructs a high-performance de-centralized system by a group of volunteer mobile devices which come together to form a resourceful unit (cloudlet). The idea is to design a model to operate as a public-resource between mobile devices in close geographical proximity. This cloudlet can provide larger storage capability and can be used as a computational resource by other devices in the network. The system needs to watch the movement of the participating nodes and restructure the topology if some nodes that are providing support to the cloudlet fail or move out of the network. In this work, we discuss the need of the system, our goals and design issues in building a scalable and reconfigurable system. We achieve this by leveraging the concept of virtual dominating set to create an overlay in the broads of the network and distribute the responsibilities in hosting a cloudlet server. We propose an architecture for such a system and develop algorithms that are requited for its operation. We map the resources available in the network by first scoring each device individually, and then gathering these scores to determine suitable candidate cloudlet nodes. We have simulated cloudlet functionalities for several scenarios and show that our approach is viable alternative for many applications such as sharing GPS, crowd sourcing, natural language processing, etc.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-04-25T12:03:54Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertacao_AdrianoHenrique.pdf: 1956295 bytes, checksum: 38ce5d73db0d44416c8653e58120f11c (MD5) / Made available in DSpace on 2017-04-25T12:03:55Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertacao_AdrianoHenrique.pdf: 1956295 bytes, checksum: 38ce5d73db0d44416c8653e58120f11c (MD5) Previous issue date: 2016-08-29 / Apesar da grande evolução tecnológica nos hardwares dos dispositivos móveis e nas redes sem fio, ainda existem grandes limitações nesses dispositivos em termos de processamento, capacidade de armazenamento e autonomia de energia, quando comparados aos desktops e servidores. O paradigma de Computação em Nuvem Móvel (MCC – Mobile Cloud Computing) permite estender os recursos computacionais dos dispositivos móveis através da utilização das técnicas de offloading computacional possibilitando um melhor desempenho as aplicações e uma redução no consumo das baterias dos dispositivos. Entretanto, a técnica de offloading nem sempre traz benefícios para o dispositivo móvel em situações de constante mobilidade do usuário, já que cada mudança de rede requer que o processo de offloading seja refeito. Esta dissertação propõe uma solução para otimizar o consumo de energia e o tempo de resposta durante as operações de offloading computacional quando o dispositivo muda de ponto de acesso. A proposta considera um esquema de gerenciamento de mobilidade baseado em Software Defined Networking (SDN) e técnica de caching remoto, que permite ao usuário receber o resultado do offloading no próximo acesso à rede, mesmo que esse fique desconectado por um longo período. A solução foi implementada em um testbed WiFi, com acesso ao ambiente MCC utilizando cloudlet baseada na plataforma OpenStack e integrada ao controlador SDN OpenDaylight. O consumo de energia obtido pela proposta que utiliza SDN/OpenFlow para o gerenciamento de mobilidade chegou a ser 11,33 vezes menor e a velocidade de processamento foi 3,23 vezes maior que do ambiente tradicional. O sistema de caching remoto, apesar de se mostrar útil em relação à rápida entrega dos resultados já processados, elevou consideravelmente o consumo de energia da bateria. A técnica de caching remoto é indicada para os casos nos quais a aplicação envia à cloudlet um grande volume de dados para ser processado e o nível da bateria do dispositivo encontra-se em estado não crítico ou quando o usuário enfrenta um longo período sem comunicação com a cloudlet. / Although the great technological evolution in the mobile devices hardware and wireless networks, remains significant limitations of these devices regarding processing, storage, and energy, when compared to desktops and servers. The paradigm of Mobile Cloud Computing (MCC) allows to extend the computational resources of the mobile devices through the use of computational offloading techniques, achieving a better performance on the part of the applications and a reduction in the battery consumption of the devices. The offloading technique does not always bring benefits to a mobile device in situations of high mobility since each network change requires the execution of the offloading process. This dissertation proposes a solution to optimize energy consumption and response times during the computational offloading operations when the device change of access points (AP). To this end, the proposal considers for such, a mobility management scheme based on SDN (Software Defined Networking) and a remote caching technique, that allows the user to receive the result from offloading in the next AP, even if he stays disconnected for an extended period. The solution was implemented in one Wi-Fi testbed, with access to the MCC environment using cloudlet based on the OpenStack platform and integrated with the OpenDaylight SDN controller. The achieved reduction of energy consumption for the mobility management proposal arrived to be 11.33 times lower, and the processing speed was 3.23 times bigger that of the traditional environment. The remote caching system, although useful in fast delivering the already processed results, considerably raised the battery energy consumption. Thus, the applicability of remote caching limits it to the cases where the application sends to the cloudlet an enormous volume of data to be processed and the battery level of the device is not critical or when the user faces an extended period without communication with the cloudlet.

With an increasing number of people currently living in urban areas, many cities around the globe are faced with issues such as increased pollution and traffic congestion. In an effort to tackle such challenges, governments and city councils are formulating new and innovative strategies. The integration of ICT with these strategies creates the concept of smart cities. The Internet of Things (IoT) is a key driver for smart city initiatives, making it necessary to have an IT infrastructure that can take advantage of the many benefits that IoT can provide. The Cloudlet is a new infrastructure model that offers cloud-computing capabilities at the edge of the mobile network. This environment is characterized by low latency and high bandwidth, constituting a novel ecosystem where network operators can open their network edge to third parties, allowing them to flexibly and rapidly deploy innovative applications and services towards mobile subscribers. In this thesis, we present a cloudlet architecture that leverages edge computing to provide a platform for IoT devices on top of which many smart city applications can be deployed. We first provide an overview of existing challenges and requirements in IoT systems development. Next, we analyse existing cloudlet solutions. Finally, we present our cloudlet architecture for IoT, including design and a prototype solution. For our cloudlet prototype, we focused on a micro-scale emission model to calculate the CO2 emissions per individual trip of a vehicle, and implemented the functionality that allows us to read CO2 data from CO2 sensors. The location data is obtained from an Android smartphone and is processed in the cloudlet. Finally, we conclude with a performance evaluation. / Med en befolkning som ökar i urbana områden, står många av världens städer inför utmaningar som ökande avgaser och trafikstockning. I ett försök att tackla sådana utmaningar, formulerar regeringar och stadsfullmäktige nya och innovativa strategier. Integrationen av ICT med dessa strategier bildar konceptet smart cities. Internet of Things (IoT) är en drivande faktor för smart city initiativ, vilket gör det nödvändigt för en IT infrastruktur som kan ta till vara på de många fördelar som IoT bidrar med. Cloudlet är en ny infrastrukturell modell som erbjuder datormolnskompetens i mobilnätverkets edge. Denna miljö karakteriseras av låg latens och hög bandbredd, utgörande ett nytt ekosystem där nätverksoperatörer kan hålla deras nätverks-edge öppet för utomstående, vilket tillåter att flexibelt och snabbt utveckla innovativa applikationer och tjänster för mobila subskribenter. I denna avhandling presenterar vi en cloudlet-arkitektur som framhäver edge computing, för att förse en plattform för IoT utrustning där många smart city applikationer kan utvecklas. Vi förser er först med en överblick av existerande utmaningar och krav i IoT systemutveckling. Sedan analyserar vi existerande cloudlet lösningar. Slutligen presenteras vår cloudlet arkitektur för IoT, inklusive design och en prototyplösning. För vår cloudlet-prototyp har vi fokuserat på en modell av mikroskala för att räkna ut CO2 emissioner per enskild resa med fordon, och implementerat en funktion som tillåter oss att läsa CO2 data från CO2 sensorer. Platsdata är inhämtad med hjälp av en Android smartphone och behandlas i cloudlet. Det hela sammanfattas med en prestandaevaluering.

Cloudlet is a recent topic that has attained much interest in network system research. It can be characterized as a PaaS (Platform as a Service) layer that allows mobile clients to execute their code in the cloud. Cloudlet can be seen as a layer at the edge of the communication network.In this thesis, we present a cloudlet architecture design which includes cloudlet code as a part of client application itself. We first provide an overview of related work and describe existing challenges which need to be addressed. Next, we present an overview design for a cloudlet-based implementation. Finally, we present the cloudlet architecture including a prototype of both client application and cloudlet server. For the prototype of a CO2 data visualization application, we focus on how to format the functions in client side, how to schedule cloudlet PaaS in the server, and how to make the server scalable. Finally, we conclude with a performance evaluation.Cloudlet technology is likely to be widely applied in IoT projects, such as data visualization of air quality and water quality, for fan control and traffic steering, or other use cases. Compared to the traditional centralized cloud architecture, cloudlet has high responsiveness, flexibility and scalability. / Cloudlet är en ny teknik som har fått stort intresse inom nätverksforskning. Tekniken kan beskrivas som en PaaS-plattform (Platform as a Service) som tillåter mobila klienter att exekvera sin kod i molnet. Cloudlet kan ses som ett lager i kanten av kommunikationsnätet.I denna rapport presenteras en cloudlet-baserad arkitektur som inkluderar cloudlet-kod som en del av själva tillämpning på klient-sidan. Vi ger först en översikt av relaterat arbete inom området och beskriver existerande utmaningar som behöver adresseras. Därefter presenterar vi en övergripande design för en cloudlet-baserad implementering. Slutligen presenterar vi cloudlet-arkitekturen, inklusive en prototypimplementation av både klient-tillämpning och cloudlet-server. I vår prototyp av en datavisualiseringstillämpning för CO2, fokuserar vi på hur man formaterar funktionerna på klientsidan, hur man schemalägger cloudlet-PaaS på serversidan, samt hur servern kan göras skalbar. Rapporten avslutas med en prestandautvärdering.Cloudlet-tekniken bedöms i stor utsträckning att användas i IoT-projekt, såsom datavisualisering av luftkvalitet och vattenkvalitet, fläktstyrning och trafikstyrning eller andra användningsområden. Jämfört med den traditionella centraliserade molnarkitekturen har cloudlet hög respons, flexibilitet och skalbarhet.

Cloud Service have been usual to solve several computer issues, some companies like Amazon or Microsoft decide invest a big amount of money to sell computer resources as PaaA or IaaS. Subsequently, new devices, now portables, emerge as common and needs cloud computing to provide resources, creating a new structure known as mobile cloud computing. Even showing several models to its architecture in mobile cloud computing, natural behavior converge to total transparency to applications and users concerning to resource location, requiring that mobile devices maintains a permanent connection and an approach that needs a procces mirroring, knows as Cloudlets. These Cloudlets should provides required resources to guarantee a cofortable perception experience to users, giving an alternate option to latency problems, local processing and unavailable connections. To obtain this quality of perception, the Cloudlet should be closest to user as possible and follow him all the time during his travel. The usual model about Cloudlets consists on services running at virtual machine, that are costly what concerns moving and startup time. As alternative this work proposes a docker container based model, which will permit a smaller startup time less tranfer data about system between datacenters evolved. This alternative shows, at proposed scenarios, is possible reduce startup overhead and moving time, benefeting users perception and opening new perspectives to implement and optimizing. / Serviços em nuvem tem se tornado uma constante para solução dos problemas computacionais convencionais, algumas empresas a exemplo da Amazon ou Microsoft investiram em infraes-trutura para vender recursos como PaaS ou IaaS. Subsequentemente novos dispositivos, agora portáteis, tem se disseminado e precisaram adotar o modelo da nuvem de provimento de recursos criando dessa maneira a Mobile Cloud Computing. Mesmo com os vários modelos de arquitetura para essa nova nuvem para dispositivos móveis, a evolução aponta em total transparência para as aplicações e usuários quanto à localização dos recursos, demandando que os equipamentos móveis necessitem uma conexão permanente e uma abordagem de espelhamento de processos conhecidas como Cloudlets. As Cloudlets devem prover recursos exigidos que garantam uma experiência de percepção de uso confortável ao usuário, contornando problemas como alta latência, processamento local e indisponibilidade de conexão. Para a obtenção dessa qualidade de percepção, a Cloudlet deve estar o mais próximo possível do usuário e acompanhá-lo durante seu deslocamento. Este trabalho apresenta uma extensão ao simulador CloudSim que possibilita a análise do efeito do deslocamento das Cloudlets através da nuvem. Como alternativa, este trabalho discute a adoção de um modelo baseado em containeres e dockers que permita um tempo de subida menor e menos dados referentes ao ambiente para serem deslocados entre os centro de processamento das cloudlets. Para avaliação da alternativa foi desenvolvida uma extensão do CloudSim que permite a mobilidade dos serviços na nuvem. Como resultado a extensão demonstrou que, para os cenários propostos, é possível reduzir o tempo e o overhead necessários para os deslocamento, beneficiando a percepção do usuário e abrindo novas premissas para avaliação, implementação e otimização

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