Research On High-efficient Data Delivery And Information Inquiry In Vehicular Networks

Vehicular ad hoc networks are a brand-new research direction incomputer networks, and one of the research hotspots in recent years. Based ona real trace dataset of more than4000taxies and2000buses in the urban areaof Shanghai, this thesis focuses on four key issues in vehicular networks,including neighbor sensing, warning message dissemination, routing protocol,and information inquiry. The researches in this thesis have positive practicalsignificance and potential application value, and they can provide services forintelligent transportation.First of all, in this thesis, for the problem of neighbor sensing, wepropose an efficient neighbor sensing protocol called ENS in vehicularnetworks. In ENS, every vehicle can perform efficient neighbor sensing withshort latency for both association and disassociation. In addition, for theproblem of warning message dissemination, by taking advantage of neighbors’information, we propose an efficient protocol called WMD for warningmessages dissemination, and WMD enables messages to disseminate in afaster speed. By taking advantage of real traces of vehicles, we haveconducted real trace-driven simulations. Performance results demonstrate thatthese proposed protocols can achieve the expected performance, andoutperform some other alternative protocols.Secondly, in this thesis, for the routing problem, we design areplication-based routing protocol called ERR for efficient routing invehicular networks, and it has the following three desirable design objectives:first, ERR delivers the majority of the messages generated in time-to-live;second, ERR achieves low end-to-end delay; third, ERR introduces as little delivery cost as possible. To achieve high delivery ratio at a low delivery cost,ERR adopts an adaptive strategy for the number of copies of a message in adistributed fashion. Performance results demonstrate that ERR can achievesignificantly high delivery ratio at a low delivery cost, when compared withsome other alternative routing protocols.Finally, in this thesis, for the problem of information inquiry, we proposean efficient information inquiry scheme called MIQ, and MIQ can achievehigher delivery ratio and lower delivery cost. In MIQ, we design queryrouting and reply routing based on vehicles’ trajectory, and a strategy ofpacket forwarding. Performance results demonstrate that MIQ can achieve theexpected performance, and outperform some other alternative protocols.