Location information about a communicating entity (41), in particular
a mobile entity, is derived by identifying intermediate nodes (42) along
the communication path being used by the entity, and then looking up, in a database
(44), the geographic significance of at least one of these nodes when considered
in a direction along the communication path towards the entity of interest. Preferably,
account is taken of any identified downstream/upstream nodes to refine the geographic
significance of a node. The geographic significance information can be compiled
by taking location fixes at a plurality of endpoint locations and associating the
location data thus obtained with the intermediate nodes traversed when communication
is effected from the corresponding endpoint locations.