Proceedings of the 6 AGILE Dates – Lieu A PORTABLE SVG-VIEWER ON MOBILE DEVICES FOR SUPPORTING GEOGRAPHIC APPLICATIONS

An important development in the area of Geographic Information Science is the use of the eXtensible Markup Language (XML) [1] for representing, transmitting and visualizing spatial data. XML allows the definition of markup languages. A well-known example is the Geography Markup Language (GML) [2] as an XML encoding of geographic features. Current Geographic Information Systems (GIS) already support GML. Another – more general example – is SVG. Scalable Vector Graphics [3] is a standard of the W3C consortium for representing vector data. Location-based services are another important development. The development of mobile applications is strongly influenced by the introduction of new mobile communication standards. Currently, the (intermediate) standard GPRS has been launched in Europe. By introducing the new mobile communication standard UMTS, this trend will be dramatically enforced. The appearance of mobile applications has also an impact on the devices used for presenting data: Instead of personal computers and workstations, Personal Digital Assistants (PDAs) or mobile telephones are used as Internet clients. However, the computing power of such devices is rather restricted compared to traditional computers. In addition, the speed and throughput of wireless networks are limited and are subject to large variations. In this paper, the support of XML-represented simple features on mobile devices will be investigated. In order to be independent of the operating system of the mobile device, Java will be assumed as programming language. The paper starts with a presentation of existing XML encodings for the representation of geographic features (sect. 2). The variants and limitations of Java on mobile devices is topic of the next section (sect. 3). Then the processing of XML documents is discussed (sect. 4). The fifth section characterizes a corresponding object model. Observing this model and the limitations and differences of the Java versions, SVG parsers and SVG viewers are designed. The paper concludes with a summary (sect. 6).