Classification Ad Hoc Networks Networking Research

Mobile Ad hoc NETwork (MANET) is a wireless multi-hop network without pre-established infrastructure. There is no central controller and MANET is completed distributed. Because of its convenience, quickness and robust, MANET can be used for emergency, temporary communication and military requirement.According to the structure MANET can be sorted into two categories: flat and hierarchical. Flat structure is mostly used in small and medium scale networks, where the nodes are completely equal to each other and the robusty is ensured. Hierarchical structure consists of clusters and is used in large scale networks for its high scalability. There are two communication methods in hierarchical networks: using single-frequency or multi-frequency. The large scale MANET needs self-organizing and working properly and efficiently under a series of protocols including clustering, routing, IP address assignment and mobility management, in which the routing protocol plays a key part because it determines the logical structure and communication performance of the network. Based on flat OLSR protocol, HOLSR (Hierarchical Optimum Link State Routing) is designed aiming to provide clustering, multi-level routing and members'management in hierarchical MANET.This paper proposes a build-up scheme for large scale heterogeneous MANET where a hierarchical architecture with multi-frequency is preferred. Optimized and combined operations of clustering, IPv6 address auto-configuration, HOLSR routing protocol and mobility management are proposed to reduce the control overhead and improve the scalability of the networks. And a mechanism of database backing up of cluster heads is designed to boost up the network's robustness. Simulation results demonstrate that the scheme improves the efficiency and performance of the organization of heterogeneous ad hoc networks and supports nodes'group mobility well.