Modeling location-based services with subject spaces

The advance in wireless networks and in positioning systems has led to the development of a new generation of mobile applications: location-based services (LBS). LBS offer highly personalized services to users of mobile devices such as telephones, pagers, and PDAs (mobile users) based on their locations, user profiles and context information. The publish/subscribe paradigm is an information dissemination model for loosely-coupled distributed applications, and is appropriate for the implementation of LBS. However, existing publish/subscribe data models and algorithms have limitations when applied to LBS. In this paper, we show how Subject Spaces -- a state persistent publish/subscribe model -- can be used to model LBS and overcome the limitations of traditional publish/subscribe systems.