차량 에드혹망을 위한 속도 인지 다중경로 라우팅 프로토콜

Abstract

The conventional routing protocols developed for mobile ad-hoc network (MANET) show low performance result when they are adapted in vehicular ad-hoc network (VANET) which has more unstable channel features such as short communication time, low packet delivery ratio, frequent link breakage, and rapidly changing topology caused by high mobility. Therefore, applications on VANET environment require a specific routing protocol to maintain stable communication between vehicles. Previous VANET routing protocols have been mainly designed by using vehicle position and/or digital map information which require installation of related devices onto all vehicles on the road. In this thesis, I introduce a new routing protocol supporting high mobility over VANET without using additional physical installations on the vehicles. It uses hopcounts, relative velocity between vehicles and surrounding condition to find the best routing transmission path. Nowadays digital vehicle velocity can be easily obtained from vehicles on the road. By exchanging vehicles’ relative velocities, the more stable and reliable paths are searched as compared to traditional MANET protocols that use only hopcount information at the time of routing path set-up. To evaluate proposed routing protocol, I compared original ad hoc on-demand multipath distance vector (AOMDV) with proposed routing protocol through NS2. Simulation results showed that proposed routing protocol achieves 5% to 10% better performance in terms of normalized routing overhead and packet delivery fraction. The proposed routing protocol doesn't need additional devices and shows better efficiency. Therefore it can be applied in vehicles easily. Also it allows stable communication environment with or without GPS system. For example, vehicle using geography routing protocol can not transmit data in undersea tunnel environment because it cannot receive signals from satellites. But proposed routing protocol ensures stability of communication and provides traditional services like video streaming services. Also the proposed routing protocol can be used to preventa traffic accident