To realize personalized web services and to design adaptable systems it is necessary to have a possibility for modeling the user’s environment and preferences. A common approach is the usage of profiles. We use communication profiles for modeling all relevant actors in a mobile scenario. The profiles which we have proposed [2] are separated into a static and a dynamic part. In this paper we suggest a new approach in designing dynamic attributes. In order to illustrate the working of these – so-called - active attributes we introduce a positioning service for heterogeneous networks. KEYWORDS Adaptable System, Active Attribute, Communication Profile, Positioning