Supporting spatial data queries for mobile services

In the last few years, many GIS applications have appeared on the Web giving users access to both spatial and non-spatial (attribute) data. Web access to GIS resources needs to address the possibility of access via handheld devices such as mobile phones, PDAs or pocket computers. Currently, only a few research studies are available on high-level user interface for spatial queries on such devices. Thus, an important research problem is to design user-friendly interfaces for mobile Web GIS. Query-by-example (QBE) is a user-friendly language developed for a relational database management system (RDBMS). Many RDBMSs have included support for spatial extensions. In this paper, we make an effort to create extensions for QBE to support spatial queries on mobile devices. It is called spatial mQBE. We show that spatial mQBE is a simple and user-friendly interface. The main strengths of this interface are its simplicity to express a query and its expressive power.