Distributed Database Design for Mobile Geographical Applications

Advanced Traveler Information Systems (ATIS) require e cient information retrieval and updating in a dynamic environment at di erent geographical scales. ATIS applications are useful in yielding a better utilization of the limited costly transportation arteries and providing value-added traveler information. Many ATIS applications are built on the functionalities provided by Geographical Information Systems (GIS), which often cannot meet extra requirements like real-time response. We investigate GIS-based systems in ATIS and propose a system architecture based on GIS and distributed database technology. Issues on data modeling, data representation, storage and retrieval, data aggregation, and parallel processing of queries are discussed. This paper introduces a distributed system architecture for ATIS based on recent technology; presents new data models for information representation; proposes data shipping for e cient query processing and function shipping in reducing communication overhead; exploits network of computers for solving complex problems more timely; and incorporates privacy protection for sensitive data.