DESKS: Direction-Aware Spatial Keyword Search

Location-based services (LBS) have been widely accepted by mobile users. Many LBS users have direction-aware search requirement that answers must be in the search direction. However to the best of our knowledge there is not yet any research available that investigates direction-aware search. A straightforward method first finds candidates without considering the direction constraint, and then generates the answers by pruning those candidates which invalidate the direction constraint. However this method is rather expensive as it involves a lot of useless computation on many unnecessary directions. To address this problem, we propose a direction-aware spatial keyword search method which inherently supports direction-aware search. We devise novel direction-aware indexing structures to prune unnecessary directions. We develop effective pruning techniques and search algorithms to efficiently answer a direction-aware query. As users may dynamically change their search directions, we propose to incrementally answer a query. Experimental results on real datasets show that our method achieves high performance and outperforms existing methods significantly.