Research On The Gateway Discovery Of Internet Connectivity For Mobile Ad Hoc Network

For the application restrict of wired communication networks, people invent wireless communication networks. In recent years, the wireless networking is rapidly becoming a prevalent form of communication. But generally speaking, the wireless communication networks are mostly in the form of cellular networks or wireless local area networks, and they need the support of infrastructures or access points. On the other hand, the deeper Internet digs into people's daily lives, the stronger the requirement of expanding wireless application space of it.A mobile ad hoc network (MANET) is defined as a collection of wireless mobile nodes forming an autonomous network without the aid of any infrastructure providing centralized administration. Each node moves randomly in the network and operates as a specialized router while communicating with others. With some characteristics as high flexibility, easy deployment and non-infrastructure, the future of MANET in the civilian sector becomes more and more brilliant.Boom of real-time service in Internet and prevalence of MANET is bound to stimulate the technical progress in the interconnection of MANET and Internet. By interconnecting MANET with Internet, people anticipate widening the wireless application space and making worldwide network seamless. Researching on the interconnectivity of MANET and Internet has become an active area of mobile access.Of course, intemetworking of mobile ad hoc networks and Intemet is a complex, systemic work and contains many important aspects of these two different networks. In this paper, author mainly concerns on the gateway discovery methods about MANET mobile access into Internet. The main tasks are as follows:1. Analyses some key techniques of intemet connectivity between mobile ad hoc networks and Internet, such as address allocation, gateway discovery, route traffic to the Intemet, load balance, microcosmic moving management and QoS guarantees.2. Reviews the researches about the gateway discovery methods at home and abroad briefly. Then the author makes a detailed description of reactive, proactive and hybrid gateway discovery methods. According to the simulation results with NS2, the author first optimizes the parameters in hybrid gateway method and then gives a comparison and analysis in various network scenarios of the three methods.3. Proposes a new adaptive intemetworking scheme that not only can adjust the scope of the gateway advertisement packets dynamically, but also can relieve broadcasting storms of flooding gateway advertisement packets with HELLO Scheme. Simulation results with NS2 show that this approach can adapt to the changing of mobile ad hoc networks' scale and node density well and can achieve good connectivity while keeping overhead costs low.