A Proactive Load-Aware Gateway Discovery in Ad Hoc Networks for Internet Connectivity

When a Mobile Ad Hoc network (MANET) is connected to the Internet, it is important for mobile nodes to detect available Internet gateway (IGW) providing access to the Internet. Gateway discovery time have strong influence on packet delay and throughput. In most of the cases, a mobile node uses minhops to the gateway to communicate 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 interface queue of waiting packets. Thus, the focus of the paper is to first analyse existing load-aware routing protocols in MANET and then based on this analysis, devise a proactive load-aware gateway discovery scheme that takes in to account size of interface queue in addition to the traditional min hop metric. This approach also allows an efficient handoff from one Internet gateway to another Internet gateway and still maintains a seamless connectivity to a fixed host. We examine the impact of traffic load and node mobility in terms of two metrics: throughput and average end-to-end delay to assess the performance of the proposed protocol. Simulation results indicate that our protocol outperforms existing solution.