Analysis And Research On Traffic Hole Phenomenon In Vanet

VANET is a new type of Moblie Ad Hoc Network (MANET), vehicles driving onthe road are virtual into a moblie node in the network, and communication facilities onthe side of the road are virtual into static nodes, and between nodes can be wirelesscommunication through multiple hops. Its application scope is very broad, in thetransportation system, it can enhance the safety of the vehicle, query the current trafficconditions, traffic accident early warning and so on, in business, it can access to theInternet provide various services for passengers. Therefore, VANET cause the attentionof a large number of research scholars; become a research focus in the MANET. Due tothe characteristics of VANET, such as topology changes fast, uneven distribution ofnodes, network link status is not stable and so on, VANET routing protocol design isvery challenging.Based on this reason, this paper studied the routing protocols of VANET, foundthat most of the current routing protocols can choose vehicle density larger sections fordata forwarding, and doesn’t take into account due to external factors such as trafficlights cyclical change caused by the uneven distribution of vehicles, vehiclecommunication interruption phenomenon. Through in-depth analysis the influence ofthe traffic hole, this phenomenon to routing protocol performance, found that whenpackers are chosen to be the traffic hole for transmission, its transmission delayincreases while submitting rate will reduce, which seriously affect the data transmissionefficiency of the network. Due to traffic hole will degrade the performance of therouting protocol, and at present most of the routing protocols are not deeply consider theimpact of this phenomenon, so this paper accordingly puts forward a based traffic holerouting protocol. The agreement first compute connectivity vehicles in all directions ofroad when packers arrived intersection, of course, taking into consideration the trafficlights change in the computing cycles, and then calculate accordingly delay of eachdirection, the direction of the minimum delay is to select the best direction. Theagreement when calculating the route considering the traffic lights change cycle, so it can avoid to appear on the data traffic hole sections for transmission. Finally, this papercombined with NS-2network simulation tools and VanetMobiSim traffic simulationtool has carried on the simulation to the protocol. Results show that the new protocol inpacket transmission delay shorter than the other protocol, on the submitted packets rateis higher than the other protocol. But it is higher in network load, it is because it canproduce a copy of the packet in the network. When the vehicle off the road after thecache clean up of its own, so its impact on network load will not last a long time. Chain,on the whole, the performance of the protocol on the whole is better than several otherprotocols.