An Architecture for Developing Context-Aware Systems

In this paper we discuss an architecture, based on a three-tiered formalism, and a development method for constructing context-aware systems. As an illustration of the principles involved in developing a context-aware system, we present a formal architecture of the Antilock Braking System (ABS). The distinguishing features of a context-aware system are perception and adaptation. The perception feature makes the system aware of the entities in the region of its governance, and triggers context-driven interaction among the entities. The nature of interaction is in general heterogeneous, with varying levels of synchrony, concurrency, and delay. However, the system is to be fully controlled and guided by the time-varying contextual conditions and system’s progress should remain both predictable and deterministic. In order to achieve determinism and predictability, the system adapts to the stimuli from its environment by learning the changing relationship among the entities and acting to fulfill the intentions expressed by the entities. The example of a context-aware system taken up for illustration in this paper is the ABS available in most of the modern day cars. We discuss ABS architecture in Section 4. The rest of the paper is organized as follows: In Section 2 we discuss the rationale for an architecture based on a three-tiered formalism, provide an overview of each tier and give a formal description of the architecture. In Section 3 we show the abstract architecture of the context-aware systems. We conclude the paper in Section 5 with a review of our ongoing work.