Spontaneous Service-Providing using WS4D in Smart Environments

2007

A growing interest for pervasive applications and the concern that users should not be disturbed by such services while they are on their regular duty have introduced several new challenges. The behavior of these applications should depend not only on their internal state and user interactions but also on contexts sensed during their execution. In this work, we propose a collaborative context-aware service platform (CoCA). The platform is data independent and can be used for context-aware application development in pervasive computing. It performs reasoning and decisions based on context data and domain based policies and semantics. Such data is organized into generic context management model (GCoM). The platform also introduces a neighborhood collaboration mechanism to facilitate peer collaboration between the pervasive devices in order to share their resources. We have developed an initial prototype of the platform. Our preliminary test on the prototype shows that the platform is a promising data independent development environment for pervasive context-aware applications.

Electronic Proceedings in Theoretical Computer Science, 2009

Location-and context-aware services are emerging technologies in mobile and desktop environments, however, most of them are difficult to use and do not seem to be beneficial enough. Our research focuses on designing and creating a service-oriented framework that helps location-and context-aware, client-service type application development and use. Location information is combined with other contexts such as the users' history, preferences and disabilities. The framework also handles the spatial model of the environment (e.g. map of a room or a building) as a context. The framework is built on a semantic backend where the ontologies are represented using the OWL description language. The use of ontologies enables the framework to run inference tasks and to easily adapt to new context types. The framework contains a compatibility layer for positioning devices, which hides the technical differences of positioning technologies and enables the combination of location data of various sources.

2008

We are living a democratization of ubiquitous environments offering a great number of services. Different devices, having different technical capacities access those services. Such environment requires an effective service discovery approach. In this paper, we start with a study of some existing service discovery approaches. Then we introduce a semantic and context-aware service discovery approach. We propose to distribute services registries in a P2P network. The registries will be structured according to the capacities and semantics of the services. To describe capacity and semantic of a service, we annotate its WSDL description.

2007

Pervasive Computing integrates numerous, casually accessible and inexpensive mobile devices with traditional distributed systems. The foremost issue of pervasive computing is Context-Awareness. Context-Aware Paradigm for Pervasive Computing Environments (CAPP) is a Service Oriented Architecture (SOA) that enhances smart service discovery in a pervasive environment. Objective of CAPP is to deliver the best service available, among a pool of similar services, to the mobile user. The system gathers the low-level service and user contexts and interprets both these contexts into the high-level ‘Who’, ‘What’, ‘Where’ and ‘When’ contexts. The interpreted high-level context is then used to discover the best available service for the user. The effectiveness of CAPP is measured in terms of success and failures where success is the systems ability to select an appropriate service from a pool of similar service to the user, based on the contexts. The projected success rate of the test cases is ...

2005

In this paper we propose CoWSAMI, a service-oriented middleware that aims at supporting context-awareness in pervasive computing environments. To this end, we rely on the standard Web services architectural style to handle the architectural heterogeneity of available context sources. CoWSAMI balances the trend between the resource limitations of available context sources and the resource requirements introduced by the aforementioned standard, by employing WSAMI, a lightweight middleware infrastructure for the development of mobile Web services. CoWSAMI provides a dynamic and highly scalable service discovery mechanism that deals with the increased behavioral mobility of available context sources. CoWSAMI further handles the behavioral heterogeneity of available context sources through a mechanism that gathers contextual information while adapting its proper behavior to the interfaces of context sources. Finally, CoWSAMI allows querying for contextual information with respect to the aforementioned organization, though a classical SQL-based interface.

International Journal of Computer & Information Science & Engineering 2 (3), 2008

Devices in a pervasive computing system (PCS) are characterized by their context-awareness. It permits them to provide proactively adapted services to the user and applications. To do so, context must be well understood and modeled in an appropriate form which enhance its sharing between devices and provide a high level of abstraction. The most interesting methods for modeling context are those based on ontology however the majority of the proposed methods fail in proposing a generic ontology for context which limit their usability and keep them specific to a particular domain. The adaptation task must be done automatically and without an explicit intervention of the user. Devices of a PCS must acquire some intelligence which permits them to sense the current context and trigger the appropriate service or provide a service in a better suitable form. In this paper we will propose a generic service ontology for context modeling and a context-aware service adaptation based on a service oriented definition of context.

Service Discovery Protocol (SDP) is important in ubiquitous applications, where a large number of devices and software components collaborate unobtrusively and provide numerous services without user intervention. Existing service discovery schemes use a service matching process in order to offer services of interest to the users. Potentially, the context information of the users and surrounding environment can be used to improve the quality of service matching. We propose a C-IOB (Context- Information, Observation and Belief) based service discovery model, which deals with the above challenges by processing the context information and by formulating the beliefs based on the basis of observations. With these formulated beliefs the required services will be provided to the users. In this work, we present an approach for automated validation of C-IOB based service discovery model in a typical ubiquitous museum environment, where the external behavior of the system can be predicted and ...

Journal of computers, 2008

The behavior of pervasive applications depend not only on their internal state and user interactions but also on contexts sensed during their execution. In this work, we present a collaborative context-aware service platform based on hybrid context management model (enhanced CoCA). It performs reasoning and decisions based on context data, context semantics, and related rules and policies. Such data is organized into a hybrid context management model (HCoM). The platform also introduces a neighborhood collaboration mechanism to facilitate peer collaboration in order to share their resources. We have developed an initial prototype of the platform. Our preliminary test shows that the platform is a promising data independent development environment for pervasive context-aware applications and it possesses good standard of scalability.

Lecture Notes in Computer Science, 2006

We consider the challenge of dynamically adapting services to context changes that occur in ubiquitous computing environments (e.g., changes in a user's activity) and propose the Context-Aware Service Enabling (CASE) platform for that purpose. The CASE platform combines context-aware service discovery with service composition, acting as an enabler for the development of adaptive context-aware applications. In this paper, we illustrate the need for context-aware service discovery and composition in pervasive 4G environments and present the architecture of the CASE platform. The CASE platform enables applications to easily adapt to changes in service availability, which may result from changes in client and/or service context. We also provide an overview of the platform's technical realization.