Supporting geographical queries onto DHTs

Location-based services (LBS) are currently receiving world-wide attention as a consequence of the massive usage of mobile devices, but such location services require scalable distributed infrastructures in order to resolve spatial queries efficiently. We propose a novel methodology to enable geographical query support to distributed hash tables (DHTs). The contributions of our methodology are the following: a) our technique is DHT-generic, b) it makes an effective clusterization of nodes and information into geographical areas, c) providing data locality without sacrificing routing and data load balancing, d) it is able to answer classical spatial range queries, as well as e) a new kind of queries we call geocast, all of them in a distributed, scalable way. We demonstrate the feasibility of our approach through representative simulations.