Presence, Location, and Instant Messaging in a Context-Aware Application Framework

A mobile user’s presence and location information often forms important input for those applications and services that must anticipate on the user’s context. Additionally, the ability to let a mobile device determine its location in an indoor environment at a fine-grained level supports the creation of a new range of personalized mobile Internet applications. The framework described here joins the concepts of presence, location and instant messaging (PLIM) in an extended existing instant messaging system, and uses a Bluetooth network infrastructure to let a mobile device determine its indoor position. Experiments show that location determination can be realized with a room level granularity1.