On Contextcast: A Context-Aware Communication Mechanism

The dissemination of messages according to clients´ contexts (i.e., location and other attributes) opens up new possibilities in context-aware systems. While geocast or content-based publish/subscribe forward messages according to client location or attributes, respectively, neither uses a combination of the two. In this paper, we present this new communication paradigm and the challenges it poses. We also extend concepts from publish/subscribe networks to efficiently deal with highly dynamic user location to lower update rates by approximating the user´s location. This reduces update rates by between 25% and 90%, depending on the granularity of the approximation.