NetClus: A Scalable Framework for Locating Top-K Sites for Placement of Trajectory-Aware Services

Optimal location queries identify the best locations to set up new facilities for providing service to its users. For several businesses such as fuel stations, cellphone base-stations, etc., placement queries require taking into account the mobility patterns (or trajectories) of the users. In this work, we formulate the TOPS (Trajectory-Aware Optimal Placement of Services) query that locates the best k sites on a road network for the prevailing user trajectories. The problem is NP-hard. The greedy approach, which is the state-of-the-art technique for this problem, is not scalable and practical for real urban-scale scenarios, primarily due to its high memory footprint beyond the capabilities of commodity machines. To overcome these challenges, we develop an indexing framework called NETCLUS that derives its power through an unique combination of FM sketches with network clustering. Empirical studies show that NETCLUS requires less than 100 s to answer the TOPS query on real datasets comprising of more than 250,000 sites and 120,000 trajectories.