G. Cheng

School Of Resource And Environmental Science in WuHan University, Wuhan, China



Achieving the full value for location-based services depends on the consistent communication across different regions, technology platforms, networks, application domains, and diverse heterogeneous databases. Therefore, data sharing is a necessity for the widespread adoption of location-based services.

The solution of this study to real-time feature-level geospatial data sharing over the wireless web for location-based service applications uses OGC web services. The framework uses Geography Markup Language(GML) for geospatial data encoding and feature relationship, which provide a basis to propagate the data update from one source to related other sources and applications, and to search and extract data at the feature level. For instant remote data access and exchange, the Web Feature Service(WFS) is used for data access and manipulation operations on geographic features from different sources through the web, the Web Map Service (WMS) produces maps in a standard image format(PNG, JPEG, SVG) of spatially referenced data dynamically from geographic information from heterogeneous geospatial databases and the Web Coverage Service (WCS) supports electronic interchange of geospatial data as "coverages". These approaches ensure basic conditions for interoperability by using standard exchange mechanism between diverse spatial data sources connected over the web. Finally, the Mobile SVG standard is used for data display on the clients browser, due to the low memory, low CPU power and limited display of mobile devices.

In this study GPS is considered a first-choice solution for the mobile positioning applications. A PDA is used in the prototype acting as a mobile device which will send request to and get responses from the LBS provider and display the results on the browser.

Several geospatial databases are used in the prototype case study to implement the proposed framework. The prototype allows the LBS clients to access and extract data at the feature level on the browser from distributed sources without downloading the full data file which will solve the problems of limited capacity of the terminal equipments. It shows that the proposed data-sharing framework is capable of sharing data without conflation, accessing and exchanging geospatial data in real time at the feature-level which will satisfy the needs of LBS clients. The prototype also shows the changes in one database will be automatically reflected on the browser of the users. Assisted by the technology of GPS, Location-based Service clients can get access to the Position of interest and the other information related to the position.