Extension of Geography Markup Language (GML) for Mobile and Location-Based Applications

摘要

Geography Markup Language (GML) has been extended for mobile and location-based applications. Three schemas are included in the extension, i.e., voice schema, tracking schema, and POI (Point Of Interest) schema. In order to handle effectively the extension, we also have designed a Spatial XQuery language and its processing modules. Because our work is based on a spatial database system, the Spatial XQuery statements are first translated into SQL statements. By working on an existing spatial database system, we can use of the existing amenities of database systems such as query optimization, spatial indexes, concurrency control, and crash recovery. Translation of the Spatial XQuery into SQL has been explained using examples. Because the results from the spatial database system are in the form of tables, we need to translate again the results into XML statements. A working example of the proposed system as an Emergency Support System is also presented. Prospected application areas of the proposed system are almost all mobile and location-based systems such as LBS (Location-based System), POI systems, tracking systems, ubiquitous systems, and distributed control and management systems.