Hybrid gateway discovery mechanism in mobile ad hoc for internet connectivity

Prevalence of real-time service in Internet and mobile ad hoc network (MANET) is bound to stimulate the technical progress in the interconnection of MANET and Internet. The interconnection is achieved by using Internet gateways, which act as bridges between MANET and Internet. When a node in MANET wants to obtain a globally routable address for Internet connection, it has to first find route to a gateway. In some network conditions, performance of Internet connectivity will be degraded by obvious unidirectional links and broadcast storm due to the blind rebroadcast of gateway discovery packets. In this paper, an effective hybrid gateway discovery algorithm for MANET is proposed to remove unidirectional links from global route computation simultaneously and enhance Internet connectivity. The routing protocol called ad hoc on-demand distance vector (AODV) has been modified to set up support hybrid network. Results using NS2 simulation show this hybrid Internet connectivity approach can provide better performance than others due to avoiding unidirectional links with little overhead.