Dynamic Generation of Context Rules

This paper presents a scheme for the dynamic generation of context rules which are useful for modifying the behaviour of mobile devices according to the social and physical settings of their users. Existing context-aware systems employ a pool of predefined rules which will be executed whenever a context of interest is sensed and captured. Defining rules at design time, however, has the following limitations: (1) The system designer should identify the set of context primitives which describe a context of interest as accurately as possible; (2) the various states of each context primitive should be predetermined and mapped to sensory data, which often requires experience or expertise; (3) the availability of mechanisms for capturing the context primitives is presupposed; if instead of the specified context primitives other context primitives are discovered, which may equally describe a similar situation, the system does not react to them, unless of course, all possible alternatives are foreseen; and (4) the desired behaviour itself may not be a priori known, as it is specific to the user. To facilitate a flexible use of context rules, they should be generated dynamically. The scheme proposed in this paper associates decision events – signifying the activities of a user – with a set of context primitives which are acquired at the time the decision events are produced. From the decision-context associations, context rules are generated. The Context-Aware E-Pad will be introduced to illustrate the scheme proposed.