General Terms Algorithms

Density queries are of practical importance in many mobility related applications. In this paper, we employ the location sensors, which are placed in a geographical area and can only detect the amount of objects moving in vicinity, to estimate the dense regions of objects. Our approach partitions the region of interest into subregions, and deploys in each subre-gion both location sensors and a processing node that issues and answers density queries. Three algorithms are proposed to process density queries on those processing nodes. Their accuracy and efficiency are empirically evaluated