Intuitively, if we construct a Voronoi diagram using service
providers (i.e., actors) as creating nodes and let each of them distribute its location along the perimeter of its
Voronoi polygon, then the Voronoi diagram becomes a
distributed service directory with bounded per-node
storage load. In this case, distance-sensitive service lookup
becomes localized (restricted in a Voronoi polygon). That is,
a service consumer (i.e., a sensor) queries in an arbitrary
direction, and will find the closest service provider once
it hits the perimeter of its home Voronoi polygon. This
intuitive solution possesses all the properties that we are
looking for; but it requires global computation. Hence, to
make it practical, as service directory, we must substitute
the Voronoi diagram with a localized planar structure with
good proximity property.