Ethylene : composants dynamiques pour la mise en øeuvre d'IHM plastiques en informatique ambiante

National audienceL'informatique ambiante impose de nouvelles contraintes sur la manière de construire les interfaces Homme- Machine (IHM). Traditionnellement centralisée sur un unique dispositif, l'IHM doit maintenant être distribuable de manière opportuniste sur un ensemble dynamique de dispositifs hétérogènes. Ces nouvelles IHM, dites plastiques, sont abordées dans cet article sous l'angle du génie logiciel (GL). Ce sont des logiciels répartis, dynamiquement adaptables, capables de s'affranchir de l'hétérogénéité des dispositifs et des logiciels. Les solutions actuelles de l'état de l'art en GL et systèmes répartis ne tiennent pas compte de la spécificité de l'interaction homme-machine. Nous proposons donc Ethylene, un cadre conceptuel et technique pour déve- lopper des IHM plastiques en informatique ambiante. Notre solution s'appuie sur l'intégration des approches dirigées par les modèles, d'une combinaison particulière de l'approche à composants et de l'approche à service et d'une manière originale de s'affranchir de l'hétérogénéité des modèles de communication inter- composant

Service Discovery Protocol Interoperability in the Mobile Environment

International audienceThe emergence of portable computers and wireless technologies has introduced new challenges for middleware. Mobility brings new requirements and is becoming a key characteristic. Mobile devices may move around differ- ent areas and have to interact with different types of networks, services and may be exposed to new communication paradigms. Thus, mobile distributed systems need to dynamically detect and adapt their interaction protocols to interoperate with services available in the environment. As a result, middleware for mobile devices must overcome two heterogeneity issues to provide interoperability in the mobile environment, i.e, heterogeneity of discovery protocols and of inter- action protocols between services. Whereas adaptation techniques from reflec- tive middleware are suitable for the latter, it is more problematic for the former if both issues are addressed concurrently. Specifically, reflective mechanisms consume too many resources like bandwidth, memory and CPU, which are lim- ited on the mobile devices. This paper first highlights why current solutions to interoperability fail to realize service discovery protocol interoperability with both high performance and low resource consumption. Second, this paper ad- dresses this open issue by using software architecture concepts enhanced with event-based parsing techniques to provide efficient, lightweight and flexible mechanisms to bring full service discovery interoperability to any existing mo- bile platform

Ethylene : composants dynamiques pour la mise en øeuvre d'IHM plastiques en informatique ambiante

National audienceL'informatique ambiante impose de nouvelles contraintes sur la manière de construire les interfaces Homme- Machine (IHM). Traditionnellement centralisée sur un unique dispositif, l'IHM doit maintenant être distribuable de manière opportuniste sur un ensemble dynamique de dispositifs hétérogènes. Ces nouvelles IHM, dites plastiques, sont abordées dans cet article sous l'angle du génie logiciel (GL). Ce sont des logiciels répartis, dynamiquement adaptables, capables de s'affranchir de l'hétérogénéité des dispositifs et des logiciels. Les solutions actuelles de l'état de l'art en GL et systèmes répartis ne tiennent pas compte de la spécificité de l'interaction homme-machine. Nous proposons donc Ethylene, un cadre conceptuel et technique pour déve- lopper des IHM plastiques en informatique ambiante. Notre solution s'appuie sur l'intégration des approches dirigées par les modèles, d'une combinaison particulière de l'approche à composants et de l'approche à service et d'une manière originale de s'affranchir de l'hétérogénéité des modèles de communication inter- composant

satin: A Component Model for Mobile Self Organisation

We have recently witnessed a growing interest in self organising systems, both in research and in practice. These systems re-organise in response to new or changing conditions in the environment. The need for self organisation is often found in mobile applications; these applications are typically hosted in resource-constrained environments and may have to dynamically reorganise in response to changes of user needs, to heterogeneity and connectivity challenges, as well as to changes in the execution context and physical environment. We argue that physically mobile applications benefit from the use of self organisation primitives. We show that a component model that incorporates code mobility primitives assists in building self organising mobile systems. We present satin, a lightweight component model, which represents a mobile system as a set of interoperable local components. The model supports reconfiguration, by offering code migration services. We discuss an implementation of the satin middleware, based on the component model and evaluate our work by adapting existing open source software as satin components and by building and testing a system that manages the dynamic update of components on mobile hosts

System support for client-server based interactive applications in ad hoc networks

With the emergence of wireless communications and mobile computing. new ways for people to interact with each other and their surrounding environment are emerging. Mobile devices, such as Personal Digital Assistants (PDAs) with wireless communication interfaces are able to communicate directly with each other if they are "close enough". If such devices are also able to act as message relays (routers), then a very powerful facility in the form of a mobile ad hoc network can be made available to applications. Although present day PDAs have sufficient networking and processing capabilities to support interesting interactive applications, as yet, there is hardly any software available for constructing and maintaining ad hoc networks and not many practical interactive applications have been built and tested. Rather, much of the research work is still at simulation and modelling stage. Thus it is difficult at this stage to decide what system support (middleware) for interactive applications a PDA should contain. This work is a step in the direction of remedying the situation by considering a class of applications where interactions between users can be supported by one of the nodes in the ad hoc network acting as a server. The thesis presents the design, implementation and evaluation of three such applications on PDAs, and based on that experience, describes what system support (middleware) for such applications is required. These applications are: Auction, Bingo game and Chatting that work over ad hoc networks. The work presented here can be used as a basis for deciding how the current generation of PDA operating systems can be extended for supporting ad hoc networking and what additional services are required for interactive applications.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Transparent and adaptive application partitioning using mobile objects

The dynamic nature and heterogeneity of modern execution environments such as mobile, ubiquitous, and grid computing, present major challenges for the development and efficient execution of the applications targeted for these environments. In particular, applications tailored to run in a specific environment will show different and most likely sub-optimal behaviour when executed on a different and/or dynamic environment. Consequently, there has been growing interests in the area of application adaptation which aims to enable applications to cope with the varying execution environments. Adaptive application partitioning, a specific form of non-functional adaptation involving distribution of mobile objects across multiple host machines, is of particular interest to this thesis due to the diversity of its uses. In this approach, certain runtime information (known as context) is used to allow an object-oriented application to adaptively (re)adjust the placement of its objects during its execution, for purposes such as improving application performance and reliability as well as balancing resource utilisation across machines. Promoting the adoption of such adaptation requires a process that requires minimal human involvement in both the execution and the development of the relevant application. These challenges establish the main goals and contributions of this work, which include: 1) Proposing an effective application partitioning solution via the adoption of a decentralised adaptation strategy known as local adaptation. 2) Enabling adaptive application partitioning which does not require human intervention, through automatic collection of required information/context. 3) Proposing a solution for transparently injecting the required adaptation functionality into regular object-oriented applications allowing significant reduction of the associated development cost/effort. The proposed solutions have been implemented in a Java-based adaptation framework called MobJeX. This implementation, which was used as a test bed for the empirical experiments undertaken in this study, can be used to facilitate future research relevant to this particular study

Middleware Awareness in Mobile Computing

The mobile computing domain presents major new challenges for middleware to overcome. In particular the mobile environment is characterised by frequent changes and often poor network QoS. Therefore, a number of middleware platforms and paradigms have been put forward to solve these issues. This in turn though has generated a problem i.e. middleware heterogeneity exists within this domain. As a consequence, mobile client applications developed upon one type of middleware are unable to interoperate and utilise services implemented on an alternative. In this paper, we examine the issue of middleware heterogeneity and propose a configurable and dynamically reconfigurable middleware platform, named ReMMoC (Reflective Middleware for Mobile Computing), which allows mobile client applications to be developed independently of the underlying middleware technology