A Road Layout Based Broadcast Mechanism for Urban Vehicular Ad Hoc Networks

Safety services of Vehicular Ad Hoc Network (VANET) require reliable broadcasts. We propose a reliable broadcast mechanism for urban roads called VANET Broadcasting for Urban areas based on Road Layout (VBURL), which tries to minimize the dependency on information that may become inaccurate to maximize the efficiency of broadcast. Specifically, the proposed mechanism takes into account the road layout information accessible from the digital map and only the real-time information obtained from the broadcast messages or beacons. VBURL basically makes the vehicle that is farthest from the current forwarding vehicle take the role of next forwarding vehicle and, if possible, makes an additional broadcast happen at the intersections where the effect of signal attenuation caused by the road side obstacles is low in order to have prompt and reliable dissemination of safety messages towards all roads connected to the intersections. The simulation results verified that VBURL achieves the same high performance as that of the compared legacy schemes in terms of reliability with much higher efficiency. Even though the message reception delay of VBURL is slightly longer than those of compared schemes, it is far less significant to impair the original purpose of safety message.