A Distributed Approach to GIS systems and Location-based Service for Internet-enabled Handheld Mobile Devices

摘要

Geographical Information Systems for PCs and mobile devices are rapidly gaining popularity. This paper presents a new server-based GIS architecture which is unique in that it is a totally WAP browser based application with user interface in HTML or WML and J2ME and relying entirely on Internet in mobile devices via wireless LANs or GPRS for accessibility. Wireless Internet-based Distributed GIS (WIDGIS) is a distributed two tier location information system. This distributed CIS architecture is based on a system of Java Servlets deployed in a system with fixed global IP address that regulates the flow of information to clients requesting service from it. The data can be textual or in the form of a map showing the relevant location information. A J2ME application, running at the client's handset, is capable of tracking GPS signals, downloading maps and indicating the user's exact position on the downloaded map, thus tracing out his movements. Also, it is possible to simulate a particular client's movements using a JAVA Swing application deployed in the server.