  This report presents a survey on how to group together in a static way planar
nodes, that may belong to a wireless network (ad hoc or cellular). The aim is
to identify appropriate methods that could also be applied for Point Processes.
Specifically matching pairs and algorithms are initially discussed. Next,
specifically for Point Processes, the Nearest Neighbour and Lilypond models are
presented. Properties and results for the two models are stated. Original
bounds are given for the value of the so-called generation number, which is
related to the size of the nearest neighbour cluster. Finally, a variation of
the nearest neighbour grouping is proposed and an original metric is
introduced, named here the ancestor number. This is used to facilitate the
analysis of the distribution of cluster size. Based on this certain related
bounds are derived. The report and the analysis included show clearly the
difficulty of working in point processes with static clusters of size greater
than two, when these are defined by proximity criteria.
