The world of spatial data is split into individual data source islands that have different thematic or spatial focuses. When attempting to integrate those data sources, severe challenges arise, since for most GIS application domains a spatial integration schema does not exist. This is also true for the newly emerging domain of mobile, context-aware applications. Since the users of these systems are mobile, transborder access to spatial data or context models is crucial for global deployment. The basis for this work is the Nexus Augmented World Schema, a conceptual schema that serves as an integration standard for autonomous spatial context servers. This paper analyzes some major spatial data standards, especially with respect to the requirements of a spatial integration schema for context-aware applications and illustrates the Nexus approach.