The Research On Reliable Unicast Routing Protocols In Vehicular Ad Hoc Networks

Vehicular Ad Hoc Networks (VANETs) can be viewed as a special form ofMobile Ad Hoc Networks (MANETs). The main goal is to build a self-organizationnetwork platform for communications between vehicles in order to achieve somepromising applications that include accident warning, driver assistance, trafficinformation query, communications between vehicles and internet access. Comparedwith traditional MANETs, there are some important differences as follows: highlydynamic topology, frequently disconnected network, sufficient energy and storage,predictable trajectory, hard delay constraints, and so on. These characteristics,however, bring some great challenges in the routes designing in VANETs.In this paper, through studying and analyzing of the unicast routing protocols inVehicular Ad Hoc Networks, we sum up their main ideas and compare them with theform of a list. According to characteristics of Vehicular Ad Hoc Networks, we presenta reliable unicast routing algorithm based on mobility prediction for VANETs in cityenvironments. At the same time, positioning errors generally exist in the positioningtechnology. The impacts on routing protocol based on position are researched.The contributions are as follows:This paper presented a reliable unicast routing algorithm based on mobilityprediction for VANETs in city environments (RUMPR). Some routing protocols haverecently been proposed, without considering the real-time network connectivity andthe reliability of packet forwarding, which could cause data forwarding interruptionand low packet delivery rate. According to this situation, we present a reliable unicastrouting algorithm based on mobility prediction. First, each participating vehicle’smobility parameters, such as speed, direction and position were taken into account toupdate routing path in real time. Second, feedback information from the MAC layerwas used to ensure success of packet forwarding. The simulation results indicate thatthe proposed routing algorithm is more suitable for rapid topology changes inVANETs.Taking into account the positioning errors in the positioning technology, theimpacts on routing protocol based on position are researched in this paper. First, wetheoretically analysis the impacts on routing algorithm caused by positioning error.Second, form two perspectives, the routing algorithm with positioning errors aresimulated. The simulation results indicate that positioning errors bring a great deal of control overhead and have small influence on packet deliver rate. Finally, threesolutions are presented to reduce these impacts in this paper.