Flooding-based Strategy Mobile Ad Hoc Networks By The Selection Algorithm And Implementation,

An ad hoc network is a self-organizing system of mobile nodes without any form of existing infrastructure. Such network can be built quickly and easily, and not limited by time and space. As it does not rely on existing infrastructure, this network can be deployed rapidly in the areas where traditional infrastructure is unavailable or unusable, such as battlefield deployment, emergency rescue and so on.Due to movement of the nodes, the topology of ad hoc network may change frequently, so traditional protocols will not suitable for such network. Research of routing protocols becomes the core of the research of ad hoc network. First, this thesis presents a study of existing ad hoc routing protocols, then provides a comparison and discussion of their respective merits and drawbacks, and analyses the flooding policies of different routing protocols. At last, this thesis gives a discussion of the flooding policy in ad hoc network to show its benefit and weakness, and makes a detailed research in directional flooding.This thesis chooses a typical directional flooding routing protocol, Distance Routing Effect Algorithm for Mobility (DREAM), and presents a particular study. According to the study of primitive DREAM protocol, this thesis proposes an improvement. The improved algorithm adds movement direction of the node as a parameter for the purpose of reducing total number of packets in the network. At last, using the NS-2 network simulator, this thesis presents the results of a detailed performance evaluation on primitive DREAM protocol and improved DREAM protocol from four aspects: end-to-end delay, data packet delivery ratio, control packet overhead and total number of packets. Compared to the primitive DREAM protocol, the improved DREAM protocol can reduce end-to-end delay, control packet overhead and total number of packets notably.At present, the research of ad hoc network is in the ascendant, and the routing protocols are the key factor. So this thesis is significant to the research and implement of the routing protocol based on flooding in theory and reality.