Research On Multicast Routing Protocols Of Ad Hoc Network Based On NS2

Wireless mobile Ad Hoc networks formed by a collection of mobile nodes through radio links are typically characterized by their multi-hop, temporary and un-center. They can be quickly built up in anywhere and at anytime, and needn't be supported by basic network devices. In these networks every terminal is equal and can move freely. Minimal configuration, absence of infrastructure, and quick deployment, make them convenient for emergency situations other than military and civilian applications and so they become widely concerned by more and more people. Multicasting plays a very crucial role in the application of Ad Hoc networks. But limited by the mobility, bandwidth and energy, the multicast protocols in traditional wire networks can't be applied in the Ad Hoc networks directly. So research and design of stable and highly efficient protocols have been very hot issues for current Ad Hoc networks.This paper mainly introduces current typical multicast routing protocols, analyzes and compares their performances in sum. MAODV(Multicast Ad Hoc Distance Vector) has been described in detail and simulated in NS2(Net Simulator2) successfully. Because the packet deliver ratio decreases sharply with the increasement of mobile speed in MAODV, a new improved protocol- MAODV-PTM(MAODV with Proactive Tree Maintenance) and its theoretical model using the mobility prediction have been invented. In this protocol the mobility and link status have been detected according to the specified algorithm before the node transmit the packet. And it selects a new valid routing to transmit the packet if the link breakage occurs soon. This method improves packet deliver ratio greatly. We implement and simulate these two protocols in NS2, and conclude that MAODV-PTM has a better performance than MAODV.This article has seven chapters as follows.Chapter 1 introduces the concepts of Ad Hoc networks. And its history, characteristic, future application and research hotspot are also simply concerned. Atlast it presents the significance and innovation about the research.Chapter 2 describes the multicast routing protocols in detail and their performances are compared and analyzed.Chapter 3 introduces the detailed process of simulating Ad Hoc protocols in NS2.Chapter 4 describes the principle of MAODV in detail.Chapter 5 implements MAODV in NS2.Chapter 6 puts forward a newly improved multicast protocol-MAODV-PTM. It is simulated in NS2 and the result shows that it has a better performance than MAODV.Chapter 7 summarizes this paper, and suggestions for future research are also given.This paper is supported by National Natural Science Foundation of China (Project No: 90304018).