Patent ID: 7330726

Claim:
A method of determining if a geographically-based service is available to a source node, comprising: (A) formatting a requesting service message that is associated with a higher-layer protocol at a source node, the requesting service message including an indicator of a message type, the indicator indicating that a first geographical position of a target node and a radius associated with a maximum distance from the first geographical position is being requested; (B) merging the requesting service message in a header of a requesting datagram; (C) sending the requesting datagram to the target node; (D) in response to (C), receiving a reply datagram from the target node; and extracting a reply position message component from the received reply datagram, the reply position message component including a reply service message that is associated with the higher-layer protocol, the reply position message component extracted from a header of the reply datagram; (E) determining the first geographical position of the target node and the radius from the extracted reply position message component; and (F) determining whether a service area of a geographically-based service is within the extracted radius defined relative to the extracted first geographical position.