Using ontologies in personalized mobile applications

Mobile devices such as personal digital assistants (PDAs) and mobile phones are in widespread use already today and converging to mobile smart phones. They enable the users to access a wide range of services and information without guiding them through their actual demands. Especially during mass events like the Olympic Games 2008 in Beijing - which was initially the context of our work - a large service space is expected to support all mobile visitors, being athletes, journalists, or spectators. Current approaches tackling such problems are location -based (i.e., location-based services), meaning that a users location is taken into consideration for service provision, and even context-aware, meaning that beyond location other characteristics of a users environment are taken into account. Such information obviously helps to deliver relevant information at the right time to the mobile users. Going one step further, a situation-aware system abstracts from the context dimensions by translating specific contexts into logical situations (such as being in the car, in a stadium). Even though many context frameworks have been introduced in the past few years, what is usually missing is the notion of characteristic features of contexts which are invariant during certain time intervals. We refer to such features as situations. Knowing the situation end users are in allows the system to better target the information to be delivered to them. This paper presents the main concepts developed for a platform named FLAME2008, which is able to support its mobile users with personalized situation-aware services in push and pull mode.