| Today's Internet is a logical network designed to move data from point-to-point or from point-to-multipoint. As it currently exists, however, the Internet has no awareness of the geography of the regions that it services. However, the coming omnipresence of communications networks and the rise of new precise location-determining technologies, such as the Global Positioning System, challenge us to enhance the infrastructure of the Internet to leverage some notion of geography so that new applications and capabilities can be introduced to the benefit of users and the applications that they use. This dissertation presents new algorithms that enhance the Internet in order to achieve a scalable internetwork-wide geographic messaging service.; Geographic routing, or geocasting, bridges the gap between a network's topology and its inherent geography. Geocasting provides the general ability of transporting data packets over multiple hops through an internetwork using only geographic coordinates as the destination criteria. Recipients within the target geographic region receive the data packets regardless of the topology or the addressing structure of the internetwork.; In order to create the new geographic routing algorithms and protocols, the following contributions were made: (1) A new geographic addressing service model for datagram networks. Based on this model, the geographic routing problem was defined. (2) A design to seamlessly integrate geographically routed packets with the Internet Protocol and a range of unicast and multicast routing protocols. (3) A set of new geocast routing algorithms that have low additional overhead, high performance, and scalability as good as, or better than, multicast routing. (4) A reference geocast routing system that adheres to the geographic addressing service model was designed and implemented.; The performance of all of the new routing algorithms and protocols were evaluated by means of simulations and by measurement of a prototype geographic routing system. |
