A Gateway Discovery Method for MANET Accessing Internet Based on Overhead Control

Looking for usable gateway is a process, which brings the biggest overhead, in MANET accessing Internet. For controlling the routing overhead effectively, a gateway discovery method for MANET accessing Internet based on overhead control, which is according to the similar between ant searching path and mobile node searching gateway, is proposed in this paper. By simulating the pheromone´s update process in ant colony algorithm, this method uses information carried in route reply packet to update gateway pheromone. According to the pheromone density on the link, link bandwidth and delay, the node computes transmission probability and transmits the route request packet. This method is simulated by NS2.29. The test result indicates that though it increases average delay appreciably, it reduces normalized routing overhead effectively and increases packet delivery radio. The validity of the method is validated.