Contextware: Bridging Physical and Virtual Worlds

Abstract

Today a variety of terms - like Ubiquitous Computing, Pervasive Computing, Invisible Computing, Ambient Intelligence, Sentient Computing, Post-PC Computing, etc. - refers to new challenges and paradigms for the interaction among users and mobile and embedded computing devices. Fertilized by a vast quantitative growth of the Internet over the past years and a growing availability of wireless communication technologies in the wide, local and personal area, a ubiquitous use of “embedded” information technologies is evolving. Most of the services delivered through those new technologies are services adapted to context, particularly to the person, the time and the place of their use. The aim for seamless service provision to anyone (personalized services), at any place (location based services) and at any time (time dependent services) has brought the issues of software framework design and middleware to a new discussion: it is expected that context-aware services will evolve, enabled by wirelessly ad-hoc networked, autonomous special purpose computing devices (i.e. “smart appliances”), providing largely invisible support for tasks performed by users. It is further expected that services with explicit user input and output will be replaced by a computing landscape sensing the physical world via a huge variety of electrical, magnetic, optical, acoustic, chemical etc. sensors, and controlling it via a manifold of actuators in such a way that it becomes merged with the virtual world. Applications and services will have to be greatly based on the notion of context and knowledge, will have to cope with highly dynamic environments and changing resources, and will need to evolve towards a more implicit and proactive interaction with users.

In this paper we explore the software engineering issues, challenges and enabling technologies associated with the provision of context aware services able to:

• (i) describe, gather, transform, interpret and disseminate context information within ad-hoc, highly dynamic and frequently changing computing environments,

• (ii) dynamically discover, inspect, compose and aggregate software components in order to identify, control and extend context, as well as overcome context barriers (like time, position, user preference, etc.),

• (iii) allow for dynamic interactions among software components in a scalable fashion and satisfying special requirements such as fidelity, QoS, fault-tolerance, reliability, safety and security,

• (iv) integrate heterogeneous computing environments and devices with different functionality, ability, form factor, size and limited resources wrt. processing power, memory size, communication, I/O capabilities, etc.

• (v) support the adaptation of novel forms of sensitive, situative, non-distracting user interfaces not limited to particular modes and styles of interaction, input-output devices or service scenarios.

In an analogy to the term “middleware” — generally understood as software technologies that serve to mediate between two or more separate (and usually already existing) software components — we introduce the term “contextware” as the core of software technologies mediating services and the context of their use, thus bridging virtual and physical worlds.