Geocast
Geocast refers to the delivery of information to a subset of destinations in a wireless peer-to-peer network identified by their geographical locations. It is used by some mobile ad hoc network routing protocols, but not applicable to Internet routing.
Geographic addressing
A geographic destination address is expressed in three ways: point, circle, and polygon, P,..., P, P). A geographic router calculates its service area as the union of the geographic areas covered by the networks attached to it. This service area is approximated by a single closed polygon. Geo Routers exchange service area polygons to build routing tables. The routers are organized in a hierarchy.
Applications
Geographic addressing and routing has many potential applications in geographic messaging, geographic advertising, delivery of geographically restricted services, and presence discovery of a service or mobile network participant in a limited geographic area