Accessing Internet from the MANET: Discovering and Selecting Gateways

Integration of mobile ad hoc network and the Internet allows ubiquitous Internet services for mobile users in a MANET. We proposed a new gateway discovery and selection scheme to rescue the network from the problems of current schemes. Our scheme uses a triggered broadcast of gateway advertisement messages at the gateways when hit by gateway discovery messages. We also bounded the dissemination of the gateway advertisement messages up to the requesting mobile node from the gateway. We combined hop count, traffic load (interface queue length), and the total number of neighbors along a route to the gateway in order to formulate a new metric for gateway selection. Our metric chooses the gateway which is not only closest but also has the route from the mobile node with less load and less dense. Simulation results show that our scheme outperforms other schemes.