The next wave of information systems to be deployed over Wide-Area Networks will feature data sources residing on Internet-enabled handheld devices, mobile laptops, and other small devices. These hosts will manage important data sets (e.g., sensor readings, medical information, financial data), and change network location as their owners move with them across geographical regions. The goal of this project is the design, implementation, and evaluation of NetTraveler, a database middleware infrastructure that locates, dynamically federates and integrates data sources residing on mobile devices and enterprise servers. The core innovations in NetTraveler are its software abstractions, protocols, and algorithms that enable NetTraveler to efficiently run queries over sites that might be mobile hosts. NetTraveler provides a context-aware query processing framework to schedule query operators based on the nature of hosts, as specified in a dynamic profile submitted by each host. NetTraveler prevents loss of query processing effort due to intermittent connectivity by means of algorithms that either cache query results, or save minimal state information necessary to resume query execution once a previously disconnected source reconnects again. Regarding broader impacts, this project combines research and educational activities to provide Hispanic graduate and undergraduate students at UPRM with the opportunity to become immerse in database research. New courses will be developed in middleware systems, and application development for mobile hosts. Expected outcomes of these activities include the source code for NetTraveler, course materials, tutorials, seminars, and research papers. All materials for these activities are freely available from the project Web site (www.ece.uprm.edu/~manuel/nettraveler/).
