Individual mobility plays a crucial role in our everyday life. Since people spend a lot of time being mobile, making mobility more efficient is a demand of most of them. Due to the latest developments in the fields of computer technology and wireless communication, computer applications became possible to meet the needs of mobile individuals. Since also positioning techniques have reached an acceptable accuracy, the location of users can be exploited by mobile applications, too. Thus, location-based services (LBS) evolved. They are preparing information and services according to a user's position. The data and operations they provide very much coincide with those available in GIS. For this reason, LBS can be understood as mobile GIS applications.

At the University of Stuttgart, a research project called Nexus has been initiated to create an open and global environment for mobile GIS.

The paper briefly introduces the idea of Nexus and describes the architecture and the data model of the platform. Then, approaches for spatial data integration are outlined.