A power-saving protocol for exact GkNN search in wireless broadcast environments

Abstract

Data broadcasting provides an effective way to disseminate information in wireless mobile environments using a broadcast channel. Such a technology can be applied to many services, including the location-based service. In this paper, we consider how to provide the group k nearest neighbors (GkNN) queries using data broadcasting. Given a dataset D and a group of points G, GkNN retrieves the k closest data points to G in D. We assume that the data is indexed by an R-tree. Since the data are broadcast sequentially on broadcast channels, adapting the previous proposed algorithms to the broadcasting environment may result in a longer latency (time elapsed between issuing and termination of the query) and a larger tuning time (the amount of time spent listening to the broadcast). We propose a simple but efficient protocol for exact GkNN queries on a broadcast R-tree in terms of the tuning time, latency, and memory usage on the clients. We last validate the proposed protocol by extensive experiments.