Survey of adaptive gateway discovery mechanisms

MANET is a short range network which enables various mobile nodes to communicate with each other. The communication range of a mobile node is limited to small area in this network so nodes of different networks which are located far are unable to share the information. Utility of MANET can be enhanced by providing internet connectivity to the mobile nodes. Since MANET and fixed networks are different in their architectures so they need an interface to connect with each other. So in this situation, Gateway, a device which act as an interface and a router provides the MANET nodes connectivity to fixed networks. In order to use the Gateway, it needs to be discovered and selected. For this process various approaches have been proposed in the past. The popular approaches are reactive, proactive and hybrid gateway discovery mechanisms. But in recent years a new approach, adaptive gateway discovery has become very popular which is very dynamic in nature. In this paper, we present a critical study of some of the proposed adaptive gateway discovery approaches with future direction.