【摘要】 由于车载自组织网中节点拓扑动态变化,针对其中紧急消息传播速率以及覆盖有效性成为挑战,本文提出双向多车道场景下可自适应于车辆密度的紧急消息广播机制。该机制优先采用基于优先级排序的同向中继节点筛选策略快速传输紧急消息,以减少转播跳数、降低时延和丢包率。当无合适的同向节点作为中继时,以基于携带-转发的反向中继节点选举策略为补充,使紧急消息能够有效传播到目标区域。仿真表明,该机制对车辆密度变化具有自适应性,与洪泛转播机制相比,具有更高的消息覆盖率以及更低的平均转发次数。更多还原

【Abstract】 Transmission rate and cover ratio of emergency message in VANET become a challenge due to the variant topology. In this paper an adaptive emergency message broadcast mechanism in Two- way Multi- lanes is proposed. The mechanism is adaptive to the variation of vehicle density. When broadcast the emergency message,the sources prefer to choose the nodes in the same direction based on priority sorting strategy to relay. So,the hops,the end- end delay and packet loss ratio will be reduced. If there is no suitable relay node in the same direction,the sources try to find the nodes in the opposite direction based on carry- forward strategy to relay.Thus,the emergency message will cover the target area effectively. The simulation results verify the adaptivity of the proposed mechanism. It is also found that the performance of proposed mechanism is superior to flooding strategy on message coverage ratio and the average number of broadcast hops.更多还原