An Efficient Gateway Discovery in Ad Hoc Networks for Internet Connectivity

Integration of MANET with the Internet is a challenging problem. It is important that dynamically deployed wireless ad hoc networks should also gain access to Internet multimedia contents through these fixed networks. When a mobile node in an Ad Hoc network wants to communicate with a node on the Internet, it has to find an efficient and reliable Internet gateway. For this purpose, the node either can send solicitation message or may depend on periodic gateway advertisement. Gateway discovery time has strong influence on packet delay and throughput. In most of the cases, a mobile node uses a number of physical hops to a gateway to communicate with a fixed host connected to an Internet. However, a minimum hop path may not always be efficient if some nodes along the path have longer queue of waiting packets. The focus of this paper is on devising an efficient proactive gateway discovery algorithm that takes into account the size of interface queue in addition to the traditional minimum hop metric to select an efficient gateway. In the MANET domain, AODV routing protocol has been used. This approach also allows an efficient handoff from one gateway to another gateway and still maintains a seamless connectivity to a fixed host. In this paper, impacts of this new metric on the gateway discovery performance are investigated. Simulation results indicate that our protocol outperforms other approaches.