Research On QoS Routing Of Ad Hoc Networks And OMNET++Simulations

Because of the unstable topology, lowed compute-capability, limited storage capacity as well as constrained-energy in Ad hoc networks, the traditional technologies(such as OSPF, RIP) of wired network are not applied to the need of Ad hoc networks. In fact, there are a lot of research related with Ad hoc routing, which QoS (Quality of Service) and multi-path routing is the two hot spots in this field.This thesis tries to propose a limited bandwidth link stability multi-path routing routing protocol (MRBS) based on AODV according to the research of QoS routing and multi-path routing in the Ad hoc network. The purpose of MRBS is in order to find maximum muti-path routing with Bandwidth Constrained. We hope the introduction of multi-path routing methods is another good method helped to QoS requirements in wireless networks. We select OMNET++ as our protocol's simulation experiments platform. In the experiment, we compare with three protocols (AODV, Q-AODV, and MRBS). The result of experiment in the same simulation environment tell us that MRBS has some performance advantages, which is higher data-transmission rate, smaller delay and modest overhead in the condition of bigger network's load and higher node's speed.MRBS has three improvements different from original AODV. First, an added bandwidth constraint QoS services is more adapted to multimedia real-time operational requirements.Secondly, the new multi-path routing discovery and traffic simultaneously transmit across multi-path with a distribution method largely reduce the capacity of link bandwidth and data-transmission delay. Thirdly, a link stability forecast mechanism based on the received power is helpful to warn the source node timely when the route will be broken. Then, source node will redistribute the traffic or rediscover the new route to reduce the data-loss rate at this time.This thesis has six chapters as follows:Chapter 1 introduce the basic concepts, features, applications and technical hotspots of the Ad hoc. The main topic and background of this thesis are also given at last.Chapter2 discuss some Ad hoc protocols and QoS technology in Ad hoc.Especially, Author give a detailed analysis of AODV protocol and QoS routing protocols.Chapter3 introduce the application of multi-routing in Ad hoc, including concept, features, performance, and stability, as well as some existing multi-routing protocols in Ad hoc.Chapter4 give a MRBS protocol based on the AODV, meanwhile, Author have explain this protocol from the following aspects: limited bandwidth, multi-path finding, and mobility forecasting in detail. .Chapter5 select OMNET++ as protocol's simulation platform and compare with three protocols (AODV, Q-AODV, and MRBS) to prove the feasibility and practice of MRBS.Chapter6 make conclusions for completed work and prospect for directions of future research in this field.This thesis is supported by National Natural Science Foundation of China (90304018).