Scenario-Based Configurable Service In Pervasive Computing

In 1991, the great scientist Mark Weiser figured out a blandly new computing future-Pervasive Computing in his article The Computer for the 21st Century in Scientific American. The key idea behind pervasive computing is that information and communication technology will be an integrated part of our environments: from toys, milk cartons and desktops to cars, factories and whole city areas - with integrated processors, sensors, and actuators connected via high-speed networks and combined with new visualization devices ranging from projections directly into the eye to large panorama displays. Thus it marks a major shift in focus away from the actual computing technology and towards people and their needs. Pervasive computing is seen as the next generation computing environments with information and communication technology everywhere, for everyone, at all times.The hardware devices and networking infrastructure necessary to realize this vision are increasingly becoming a reality. Researchers all over the world working on Pervasive Computing contribute to the development of new concepts, technologies, products and services. Lots of research projects are practicing a user-centered, unified, and adaptable human-computer interaction environment. Yet precious few applications run in the infrastructure. This lack of applications is directly related to the fact that it is difficult to design, build, and deploy applications in a pervasive computing environment. For this vision to become a reality, developers must build applications that constantly adapt to a highly dynamic computing environment. The pervasive computing environment has been mapped as a combination of mobile and stationary devices that draw on powerful services embedded in the network to achieve users' tasks. The result is a giant, ad-hoc distributed system, with tens of thousands of devices and services coming and going. Consequently, the key challenge for developers is to build adaptive applications that continue to provide useful services. Meanwhile at the design time, they do not know how many services are available and how many devices would access to the application. As part of our research into pervasive computing, we are building describer, a scenario-based adaptable service architecture for pervasive computing. Based on our experiences with this architecture, we believe that applying the separation of concerns principle would be helpful to cope with adaptability problem. Task abstraction as the basic of configuration for pervasive application, is the process of transforming peoples' informal notions of what is desired into a precise description. These descriptions may then be suitable for mediating communication with oneself overtime, one's own community, and other communities. During this process people are best able to describe complex systems in a fragmentary and highly contextual manner. Scenarios which are partial description of system and environment behavior scenarios play an important role in envisaging by mediating communication and by describing alternative situations and rationale explored during design. Consider two categories of scenario writers, domain experts and software experts. Domain experts have spent years learning both the complex vocabulary of their domain and how to react in the complicated situations arising in this domain. This is also true for software experts who have spent years learning the formality of programming and formal logic. When domain and software experts communicate with each other during meetings, they predominantly use their own domain-specific vocabularies. While trying to establish connections, they will actually mix their terminology with the terminology from others' outside their area of expertise, and by doing so leave the communication open to misinterpretation. We propose a scenario-based participatory design model which provides them a simple but useful mechanism to share their knowledge to build the customized applications by separating system model into domain model and design model. In this model, domain experts, together with users, stakeholders focus on the logic rules (domain model) and programmers works on the implementation (design model). In order to formalize the requirement, we introduce a Human-Agent interaction language to transform users' goals and domain rules into executable scenarios. We also design and implement a FIPA-compliant agent platform - describer to realize the configuration of applications according to different requirements.