Abstract
Geocasting can be employed as a mechanism to deliver messages to mobile nodes, which are present within a specified geographical area. As opposed to traditional multicast mechanisms where a node becomes a member by explicitly joining a multicast group, in geocasting, a host automatically becomes a geocast group member if its location belongs to the specified region of the geocast. This thesis presents a variation to the GeoTORA algorithm called GridGeoTORA and compares its performance with the GeoTORA algorithm. The GeoTORA algorithm maintains a geocast region oriented DAG (directed acyclic graph) for mobile nodes present in the geocast region. In the proposed protocol, the network space is now divided into regions called cells. A node having data to send to the geocast region maintains a DAG for the nodes present in all the cell(s), which include(s) the geocast region. Using a grid based network for geocasting increases the scope of the geocast packet flood in order to achieve higher accuracy of geocast flooding and also reduce the delays required to establish the DAG to the geocast group. This algorithm aims to maintain a contant number of DAGs (the maximum number of DAGs being equal to the number of cells in the network grid) even when the number of geocast regions increases to an arbitrarily large number.
Macwan, Mikin (2001). Geocasting in mobile ad hoc networks: a grid based approach to GeoTORA. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2001 -THESIS -M336.