A Hilbert Curve-Based Distributed Index for Window Queries in Wireless Data Broadcast Systems

Location-dependent spatial query in the wireless environment is that mobile users query the spatial objects dependent on their current location. The window query is one of the essential spatial queries, which finds spatial objects located within a given window. In this paper, we propose a Hilbert curve-based distributed index for window queries in the wireless data broadcast systems. Our proposed algorithm allocates spatial objects in the Hilbert-curve order to preserve the spatial locality. Moreover, to quickly answer window queries, our proposed algorithm utilizes the neighbor-link index, which has knowledge about neighbor objects, to return the answered objects. From our experimental study, we have shown that our proposed algorithm outperforms the distributed spatial index.