Research And Implementation Of Cluster Head Gateway On Interconnection Of MANET And Internet

MANET (Mobile Ad hoc Network) is a kind of temporary autonomous wireless network system, which consists of a group of mobile nodes that can serve as both host and router. MANET can be established quickly without any fixed infrastructures, thus it has been widely applied in military, personal communication, emergency service and other occasions where equipments and infrastructures can not be easily deployed, and it has become an important part of the next generation network.In recent years, more and more people want to use mobile terminals to access the Internet and enjoy the web services at any time and any place. Interconnecting MANET and Internet can not only make people convenient to access the Internet, but also make the web services extend to such region without any infrastructures. A gateway is a bridge to interconnect two heterogeneous networks, it has become a research focus on interconnection of MANET and Internet.This thesis presents a kind of cluster head gateway based on PSO clustering algorithm and inter-cluster multipath, which makes improvements mainly from three aspects. First, in this thesis, a MANET cluster head is just a gateway, a cluster head gateway acts as both the cluster head and the gateway. When the communication occurs within a cluster or among clusters, the cluster head gateway performs the original function of a cluster head, when a MANET node wants to access the Internet, the cluster head gateway opens the gateway mode. Second, network clustering belongs to an optimization problem, however, PSO algorithm is an effective solution. Based on the original PSO algorithm, the thesis introduces a monotone decreasing inertia weight strategy, which can not only prevent the algorithm from falling into local optimum, but also accelerate the convergence speed. After that, a clustering algorithm based on the improved PSO algorithm is proposed, named PSO-MDIW, which takes bandwidth, energy, intra-cluster distribution, inter-cluster distribution into account. Third, in order to improve the link fault tolerance and the bandwidth utilization, the thesis designs an inter-cluster multipath routing protocol according to the proportion of bandwidth, named BMR-AODV, which can effectively balance the network load.This thesis simulates PSO-MDIW clustering algorithm and BMR-AODV routing protocol in different scenarios based on NS2network simulation software. The simulation results show that PSO-MDIW clustering algorithm can well balance the global search and the local search, and BMR-AODV routing protocol has different improvements in terms of packet delivery ratio, average end-to-end delay, and network lifetime.