Anycasting and Geocasting in Mobile Ad Hoc Networks

This technical report considers the problem of providing a geocast service, which is useful for sending messages to everyone in a specified geographical region, in mobile ad hoc networks. In the report, a novel geocasting algorithm combining unicasting and flooding is proposed for an efficient geocast packet delivery. TORA (unicast) routing protocol is first modified to be able to perform anycasting service. Our geocasting algorithm is then obtained using a small variation on the anycasting protocol. The proposed protocol, named "GeoTORA", also incorporates flooding, but flooding is limited to nodes within a small region. This integration of TORA and flooding can significantly reduce the overhead of geocast delivery, while maintaining reasonably high accuracy.