XML Fragment Caching for Small Mobile Internet Devices

Whenever small mobile devices with low bandwidth connections to a server execute transactions on common XML data, then efficient data exchange between client and server is a key problem to be solved. However, a solution should also consider client-side cache management for the XML data, synchronization of concurrent access to the XML data, and lost connections during transaction execution. In order to reduce data exchange between client and server, our protocol reuses data stored in the client's memory instead of reloading data into the client's memory wherever possible. A key idea is that the server keeps a 'living copy' of the XML fragments in the client's memory for efficient cache management. Furthermore, our protocol integrates well with a validation based scheduler in such a way that offline work and transaction completion after lost connections are supported. Finally, we present some optimizations that further reduce client-server communication.