Abstract
This paper identifies requirements for querying andaccessing context information in mobile and pervasivecomputing environments. Furthermore it studiesexisting query languages showing that they satisfy onlya subset of these requirements or cover some of themonly to a limited extent. A new context query languageis presented to overcome these shortcomings,improving the state of the art in several respects:heterogeneous representations of context information,definition of complex filtering mechanisms, elaborateaggregation functions and ontology integration, all inone language.