Continuous detour queries in indoor venues

In this paper, we study continuous detour queries in the indoor space. A continuous detour query finds the nearest indoor detour object like an ATM or a printer for a moving user walking towards a target location in an indoor venue, where the detour distance for an indoor object is measured as the total indoor distance of the object from the user's current and target locations. The continuous detour query has been already studied for the outdoor space, but the solutions are not adaptable for the indoor space due to the unique characteristics of indoor venues. We develop the first solution for efficient processing of the continuous detour query in the indoor space. The novelty of our solution comes from the computation of safe zones for the indoor objects by exploiting the geometric properties of hyperbolas, additively weighted Voronoi diagram and indoor partitions. The safe zone represents an area such that the nearest detour object remains unchanged as long as the user is in this area. The key ideas behind the efficiency of our solution are reducing the number of re-evaluation of the detour queries for the location change of a moving user, pre-computing the safe zones, and indexing them using a grid structure. The experiments show that our solution can process continuous detour queries efficiently and reduces the communication overhead.