Adaptive Gateway Discovery in Mobile Ad Hoc Networks. A Low-overhead and Scalable Solution based on Proxies.

In the last years, many authors have addressed the problem of interconnecting Mobile Ad Hoc Networks (MANET) to the Internet, via one or more attachment points called gateways. The protocol employed to discover available gateways and set up routes to the Internet should not incur in a big overhead, due to the scarce resources of ad hoc networks. However, previous proposals do not meet this requirement either when the number of traffic sources or available gateways increases. In this paper, we develop a gateway discovery algorithm which dynamically adapts its behavior depending on the number of active traffic sources which are in the MANET. In addition, the approach employs proxies (intermediate nodes which make use of available local information) to further reduce the control overhead. A mathematical model for this algorithm and the previous approaches is provided. By means of both an analytical and a simulation-based study, our proposed scheme is shown to greatly outperform the remaining solutions in terms of overhead reduction, while it is still able to provide a high packet delivery ratio. Besides, our proposal scales well regarding the number of sources and gateways.