492 research outputs found
The 3DMA Middleware for Mobile Applications
Mobile devices have received much research interest in re- cent years. Mobility raises new issues such as more dynamic context, limited computing resources, and frequent disconnections. To handle these issues, we propose a middleware, called 3DMA, which introduces three requirements, 1) distribution, 2) decoupling and 3) decomposition. 3DMA uses a space based middleware approach combined with a set of workers which are able to act on the users behalf either to reduce load on the mobile device, or to support disconnected behavior. In order to demonstrate aspects of the middleware architecture we consider the development of a commonly used mobile application
Blackboard Rules for Coordinating Context-aware Applications in Mobile Ad Hoc Networks
Thanks to improvements in wireless communication technologies and increasing
computing power in hand-held devices, mobile ad hoc networks are becoming an
ever-more present reality. Coordination languages are expected to become
important means in supporting this type of interaction. To this extent we argue
the interest of the Bach coordination language as a middleware that can handle
and react to context changes as well as cope with unpredictable physical
interruptions that occur in opportunistic network connections. More concretely,
our proposal is based on blackboard rules that model declaratively the actions
to be taken once the blackboard content reaches a predefined state, but also
that manage the engagement and disengagement of hosts and transient sharing of
blackboards. The idea of reactiveness has already been introduced in previous
work, but as will be appreciated by the reader, this article presents a new
perspective, more focused on a declarative setting.Comment: In Proceedings FOCLASA 2012, arXiv:1208.432
Mobile Databases: a Selection of Open Issues and Research Directions
International audienceThis paper reports on the main results of a specific action on mobile databases conducted by CNRS in France from October 2001 to December 2002. The objective of this action was to review the state of progress in mobile databases and identify major research directions for the French database community. Rather than provide a survey of all important issues in mobile databases, this paper gives an outline of the directions in which the action participants are now engaged, namely: copy synchronization in disconnected computing, mobile transactions, database embedded in ultra-light devices, data confidentiality, P2P dissemination models and middleware adaptability
The simplicity project: easing the burden of using complex and heterogeneous ICT devices and services
As of today, to exploit the variety of different "services", users need to configure each of their devices by using different procedures and need to explicitly select among heterogeneous access technologies and protocols. In addition to that, users are authenticated and charged by different means. The lack of implicit human computer interaction, context-awareness and standardisation places an enormous burden of complexity on the shoulders of the final users. The IST-Simplicity project aims at leveraging such problems by: i) automatically creating and customizing a user communication space; ii) adapting services to user terminal characteristics and to users preferences; iii) orchestrating network capabilities. The aim of this paper is to present the technical framework of the IST-Simplicity project. This paper is a thorough analysis and qualitative evaluation of the different technologies, standards and works presented in the literature related to the Simplicity system to be developed
Enabling Personalized Composition and Adaptive Provisioning of Web Services
The proliferation of interconnected computing devices is fostering the emergence of environments where Web services made available to mobile users are a commodity. Unfortunately, inherent limitations of mobile devices still hinder the seamless access to Web services, and their use in supporting complex user activities. In this paper, we describe the design and implementation of a distributed, adaptive, and context-aware framework for personalized service composition and provisioning adapted to mobile users. Users specify their preferences by annotating existing process templates, leading to personalized service-based processes. To cater for the possibility of low bandwidth communication channels and frequent disconnections, an execution model is proposed whereby the responsibility of orchestrating personalized processes is spread across the participating services and user agents. In addition, the execution model is adaptive in the sense that the runtime environment is able to detect exceptions and react to them according to a set of rules
Adaptable Mobile Transactions and Environment Awareness
National audienceMobile environments are characterized by high variability (e.g. variable bandwidth, disconnections, different communication prices) as well as by limited mobile host resources. Such characteristics lead to high rates of transaction failures and unpredictable execution costs. This paper introduces an Adaptable Mobile Transaction model (AMT) that allows defining transactions with several execution alternatives associated to a particular context. The principal goal is to adapt transaction execution to context variations. An analytical study shows that using AMTs increases commit probabilities and that it is possible to choose the way transactions will be executed according to their costs. In addition, the middleware TransMobi is proposed. It manages environment awareness and implements the AMT model with suitable protocols.Les environnements mobiles sont caractérisés par une grande variabilité (bande passante variable, déconnexions, prix de communication différents, etc.) ainsi que par des uni-tés mobiles à ressources limitées. Ces caractéristiques entraînent un nombre important de défaillances transactionnels et des coûts d'exécution imprévus. Cet article introduit un modèle de transactions mobiles adaptables (AMT) permettant de définir des transactions avec plusieurs alternatives d'exécution. Le principal objectif est d'adapter l'exécution des transactions aux variations du contexte. Une étude analytique montre que les AMT augmentent la probabilité de validation et qu'il est possible de choisir le type d'exécution en fonction de son coût. Nous proposons également l'intergiciel TransMobi gérant la perception de l'environnement et implantant le modèle AMT à l'aide de protocoles appropriés
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Context-awareness for mobile sensing: a survey and future directions
The evolution of smartphones together with increasing computational power have empowered developers to create innovative context-aware applications for recognizing user related social and cognitive activities in any situation and at any location. The existence and awareness of the context provides the capability of being conscious of physical environments or situations around mobile device users. This allows network services to respond proactively and intelligently based on such awareness. The key idea behind context-aware applications is to encourage users to collect, analyze and share local sensory knowledge in the purpose for a large scale community use by creating a smart network. The desired network is capable of making autonomous logical decisions to actuate environmental objects, and also assist individuals. However, many open challenges remain, which are mostly arisen due to the middleware services provided in mobile devices have limited resources in terms of power, memory and bandwidth. Thus, it becomes critically important to study how the drawbacks can be elaborated and resolved, and at the same time better understand the opportunities for the research community to contribute to the context-awareness. To this end, this paper surveys the literature over the period of 1991-2014 from the emerging concepts to applications of context-awareness in mobile platforms by providing up-to-date research and future research directions. Moreover, it points out the challenges faced in this regard and enlighten them by proposing possible solutions
Context Aware Adaptable Applications - A global approach
Actual applications (mostly component based) requirements cannot be expressed without a ubiquitous and mobile part for end-users as well as for M2M applications (Machine to Machine). Such an evolution implies context management in order to evaluate the consequences of the mobility and corresponding mechanisms to adapt or to be adapted to the new environment. Applications are then qualified as context aware applications. This first part of this paper presents an overview of context and its management by application adaptation. This part starts by a definition and proposes a model for the context. It also presents various techniques to adapt applications to the context: from self-adaptation to supervised approached. The second part is an overview of architectures for adaptable applications. It focuses on platforms based solutions and shows information flows between application, platform and context. Finally it makes a synthesis proposition with a platform for adaptable context-aware applications called Kalimucho. Then we present implementations tools for software components and a dataflow models in order to implement the Kalimucho platform
A Query-Centric Approach to Supporting the Development of Context-Aware Applications for Mobile Ad Hoc Networks, Doctoral Dissertation, August 2006
The wide-spread use of mobile computing devices has led to an increased demand for applications that operate dependably in opportunistically formed networks. A promising approach to supporting software development for such dynamic settings is to rely on the context-aware computing paradigm, in which an application views the state of the surrounding ad hoc network as a valuable source of contextual information that can be used to adapt its behavior. Collecting context information distributed across a constantly changing network remains a significant technical challenge. This dissertation presents a query-centered approach to simplifying context interactions in mobile ad hoc networks. Using such an approach, an application programmer views the surrounding world asa single data repository over which descriptive queries can be issued. Distributed context information appears to be locally available, effectively hiding the complex networking tasks required to acquire context in an open and dynamic setting. This dissertation identifies the research issues associated with developing a query-centric approach and discusses solutions to providing query-centric support to application developers. To promote rapid and dependable software development, a query-centric middleware is provided to the application programmer. These solutions provide the means to reason about the correctness of an application\u27s design and potentially to reduce programmer effort and error
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