【摘要】 为了满足VANET中交通安全信息实时可靠传输的需求,文中提出了一种基于自适应认证重传机制的多跳广播路由算法(ACR-BA).首先,为了节省网络资源,ACR-BA算法设计了两种短控制包,有效地抑制了传输冗余;其次,为了降低竞争信道的碰撞概率,基于地理位置划分了候选节点集,并结合控制包认证机制在一个候选节点集中仅确定出唯一的转发节点;然后,根据网络负载状况设计了一种基于单位基准时隙的自适应机制,设置尽量小的退避等待时间,提高信息广播的实时性;最后,设置了针对短控制包和数据包的超时重传保障机制,在保证算法实时性的基础上最大限度地提高可靠性.理论分析和仿真结果表明,与传统洪泛算法和时隙1坚持算法相比,ACR-BA算法有效地降低了网络中的冗余数据量,在实时性和可靠性两方面均有较大的性能提高.更多还原

【Abstract】 In order to improve the safety,vehicles in the event of traffic jams,accidents or other emergency conditions should distribute the safety related information out reliably and timely.An Adaptation and Certification Retransmission based multi-hop Broadcast Algorithm(ACR-BA)for VANET(Vehicular Ad-Hoc Networks)is proposed in the paper.Firstly,by introducing two short certification packets(RTF/ATF:Request To Forward/Answer To Forward)and dividing all nodes into different parts with different priorities,only one node is selected to rebroadcast in ACR-BA algorithm.This method can reduce the probability of collision during the nodes contending for the channel and the amount of data redundancy.According to the network’s load,we then use the adaptive unit slot time to reduce the backoff time and the time for information broadcasting.Finally,both ATF and data packets retransmission mechanism is proposed to improve the block error rate.Theoretical and simulation results demonstrate that,compared with the Mflood and Slotted 1-persist algorithms,the proposed ACR-BA algorithm can reduce the redundant data,shorten the time for broadcast,and also improve the reliability.更多还原