一种用于高速公路上防车辆连环碰撞的V2V广播协议

目前,V2V网络主要通过周期性广播紧急预警消息(emergency warning message,EWM)来解决高速公路上经常发生的连环碰撞事件,但是周期性广播EWM容易产生广播风暴,造成大量消息的传输失败和传输延时,从而影响了预警网络的可靠性和效率.通过研究V2V网络中的各种无线广播协议,提出了一种用于高速公路上防止车辆连环碰撞的广播协议.协议在方向性广播的基础上,通过发送ACK帧选择广播车辆并由广播车辆负责广播EWM来解决广播协议中的EWM冗余问题.仿真实验表明:协议能有效地控制EWM的冗余问题,提高EWM传输的可靠性并降低传输延时.

A V2V Broadcast Protocol for Chain Collision Avoidance on Highways

As the speed of a vehicle on the highway can reach as high as over 100km an hour, so drivers on highways have less reaction time than drivers in other road situations. That's why chain collision happens frequently on highways. In this paper, V2V (vehicle to vehicle) network is applied to solve the problem of chain collision on highways. Currently, the V2V network relies on periodic broadcast to disseminate the emergency warning messages (EWM) to locations beyond the transmission range of individual nodes on highways. But along with it, there comes the problem of broadcast redundancy, which reduces the reliability and efficiency of the warning system. In this paper, by studying different broadcast strategies, a new efficient IEEE 802.11 based broadcast protocol of communication in vehicle group is proposed for preventing chain collision on highways. The proposed protocol designs to figure out broadcast redundancy, transmission latency, reliability problems of multi-hop broadcast on highways, and achieves the purpose by sending the ACK frame to choose broadcast vehicles on the basis of directive broadcast. The simulation result shows that it can effectively handle the broadcast redundancy problem of EWM and achieve higher reliability but lower transmission latency of message dissemination among vehicles on highways.