Spontaneous integration of services in pervasive environments
Noha Ibrahim · OpenGrey (Institut de l'Information Scientifique et Technique) · 2008
If mobile computing brought challenges and constraints to distributed systems, it kept evolving with the evolution of the technology. The mission of mobile computing is to allow users to access any information using any device over any network at any time. When this access becomes to every information using every device and over every network at every time, we can then say that mobile computing has evolved to what we now call pervasive computing. A computing infrastructure where everything is a service offers many new system and application possibilities. Among the main challenges, however, is the issue of standardized way of application development in such heterogeneous environments. The natural way of doing this is by performing service composition, either by creating services and composing them according to requirements, or adapting and reusing existing services in order to achieve a given task. In such open environment the ability of services to adapt and be extended represents the primary driving force. These two actions of composition and adaptation are only possible if services are implemented and described in interoperable languages. For that reason, service transformation is a critical step preceding any composition or adaptation action. In this thesis, we focus our interest upon the intersection of two major domains, the service oriented architectures meeting the pervasive computing, and propose a novel solution to integrate services in a pervasive environment. The main contributions of this thesis are threefold. They arise from the lacks noticed in current service integration middleware for the pervasive environments. If many middleware dealt with one or more of our service problems - transformation, composition, adaptation - few proposed a unified vision for the service integration in pervasive environment, a management of the functional and non-functional properties of services during the integration, and especially, a spontaneous service integration that extends environments transparently with functionalities. We define the SIM model a Service Integration Middleware model adapted to service integration middleware for pervasive environment. We give our middleware instantiation, MySIM and provide the services functional and non-functional equivalence and composable relations to define service transformation, service composition, and service adaptation. Based on these relations, spontaneous service integration adapted to pervasiveness is explained. We developed a prototype as a proof of concept that we tested over MyStudio environment. We think that our work on spontaneous service integration with others related to intelligence, smartness and pro-activity lead to the development of the Ambient Intelligence, the very likely probable evolution of pervasive computing.