Research And Simulation Of Routing Strategy Based On Ad Hoc Network

Ad hoc network is composed by a group of mobile nodes with wireless transceiver,which does not rely on the ground station or other infrastructure.Nodes in Ad hoc network communicate with each other by multi-hop forwarding and this network has the advantages of rapid networking,anti-destroy,especially suitable for assault and rescue,disaster relief and military coordination.As one of the core areas of Ad hoc,routing policy has great impact on its performance and routing metric also plays an important role in routing.This thesis has mainly conducted research on the routing of a TDMA Ad hoc network.Through an analysis of the Multi-hop transmission process of a TDMA Ad hoc network with a retransmission mechanism,this thesis has naturalized the factors affecting the quality of link layer into the time overhead,and presented the two measuring approaches of routing,namely,the total average time delay and the average receiving time delay.This thesis has also conducted a mathematical derivation about how the above routing measuring indexes,put up with their respective closed formula expression,and further verify this derivation through simulation.This thesis has testified that this measuring formula of the average receiving time delay is a more reasonable routing measuring approach with isotonicity.Finally,this thesis has designed an OLSR routing protocol on the basis of the minimum time cost of routing measurement,and illustrated the control message format,MPR selection and routing calculation process.The thesis has created a simulation environment of different scenes for the routing protocol through NS-3 simulator,and the simulation results has proved that the improved OLSR protocol has better performance in network throughput,average end-to-end time delay,and packet loss probability.