1. A method of identifying at least one node close to a first node in a network, comprising: selecting a set of candidate nodes from a plurality of nodes based on location information for the candidate nodes and the first node, wherein the selection is made based on comparing a distance from the first node and a distance from each node of the plurality of nodes to each one of a plurality of global landmark nodes; applying a clustering algorithm, using a computer processor, to the location information for the candidate nodes and the first node; and identifying a subset of the set of candidate nodes closest to the first node based on results of applying the clustering algorithm.