Location-aware mobile applications based on directory services

Location-aware applications are becoming increasingly attractive due to the widespread dissemination of wireless networks and the emergence of small and cheap locating technologies. We developed a location information server that simplifies and speeds up the development of these applications by offering a set of generic location retrieval and notification services to the application. The data model and the access protocols of these services are based on the X.500 directory service and the lightweight directory access protocol LDAP since these are becoming the standard attribute-value-pair retrieval mechanisms for Internet and Intranet environments. This approach establishes a smooth migration path from conventional to location-aware applications. The paper presents the location information server concepts, defines its directory data model and access services, and discusses the implementation options of the location information server.