Research On Key Techniques Of Mobile Ad Hoc Network

With the increasing demand for personal communication, the developments and applications of Ad hoc networks are promising. Because Ad hoc networks have the characteristics of multi-hop communication, highly dynamical topologies and limited resource etc., it is necessary to perform in-depth study on developing the algorithms and protocols that are applicable for Ad hoc networks. This paper concerns some key technologies such as constructing mobility mode, clustering algorithm and routing protocol.This paper makes a deep study on clustering algorithms. It focuses on different density Ad hoc networks, and two clustering algorithms based on computational geometry are proposed: Clustering Algorithm Based on Geometric Programming (GPBCA), Clustering Algorithm applied to Hierarchical Management (HMCA). GPBCA integrates network link planning, which uses triangulation method, in clustering algorithm. Therefore, GPBCA can balance the burden of certain clusterheads and control the size of clusters. Because proposes a concept of the relativity nodes and only need to send message to relativity nodes, GPBCA reduces bandwidth wastage. Finally, simulations perform performance comparisons and evaluations between GPBCA and LOWID algorithm. HMCA uses Voronoi diagram to describe the direct link between clusterheads, and modifies the three-level (Manager-Clusterhead-Member) network management. HMCA deploys clusterheads with Modified Voronoi diagram in order to increase the coverage areas of the network, and it puts the relative mobility into clustering, hence, it avoids complicated computing.With the more and more requirements to mobile communication, mobile multimedia communication becomes more and more popular. This paper proposes a mobility model called MCM that not only meets the requirement of multimedia communication but also fits for obstacle environment. MCM is designed in consideration of the presentation of obstacles. MCM not only provides network connectivity but also constructs enough redundant links, therefore, it can ensure massive data communication and provide standby route for link break. A routing algorithm called MRA, using MCM, is proposed for multimedia services in Ad hoc networks. MRA has two advantages: one is that this algorithm fits for multimedia communication, and the other is that it can be used in obstacle environment.