Incremental Data Prefetching for Map Service in Mobile Navigation Application

Map service, the most frequently used service in mobile navigation application, is always the bottle-neck due to the continual map refresh, limitation capacity of wireless network and the vast data volume of the vector map. Data prefetching, responsible for fetching data from Map Server forehand, is considered to be an efficient way to increase map refresh. However, the sticking point is to decrease the data participant in transfer and display. Other than treat all the data objects equally, this paper take the objects´ display level into account during prefetching, and presents a hierarchical data management and incremental prefetching strategy based on Hierarchical Hilbert grid, which extends traditional Hilbert grid and curve to multi-level map space, and uses a binary serial number to serialize sub-grids for the sake of describing both spatial and neighborhood relationship among objects.