The Research Of QoS Multipath Routing Based On SWAN In Ad Hoc Network

Ad Hoc network is a dynamic multihop wireless network that is established by a set of mobile nodes on a shared wireless channel. Investigations on Ad Hoc network have received considerable interest in recent years due to its capability to deploy quickly without any infrastructure. Ad Hoc network is getting more and more extensive attention and has already become an important direction in mobile communication technology,and will occupy the important position in future communication technology. With the increasing need of multimedia services in Ad Hoc network,providing QoS support is proposed. However,considering the moving of nodes in Ad Hoc network and constantly variety of network topology, how to design routing protocols which support QoS require is challenging and have been the important content of Ad Hoc network research.This thesis firstly introduces the basic characteristic, the research actuality of routing protocols and the guarantee of QoS of Ad Hoc network. Due to most routing protocols at present in Ad Hoc network are unipath. These protocols need a new discovery whenever a path breaks. So frequent route discoveries can cause some problems such as packet delay too long and throughput of network too low, and can't support QoS very well. To avoid these problems, this thesis realizes a multipath routing protocol AOMDV. Through the simulation experiment under NS2, it analyzes the performance of AOMDV. This thesis then describes the principle and the three distributed algorithms of SWAN model. SWAN uses feedback based rate control mechanisms to control the best effort flows. The admission control and congestion control are strongly adaptive in their response to changes in resource availability. At last, it hangs AOMDV and SWAN together, and gets a new integrated system Q-AOMDV. Then it simulates Q-AOMDV under NS2, analyzes its advantages and disadvantages, and draws a conclusion.