摘要
为提高车联网VANETs(vehicle Ad Hoc networks)中紧急消息的传输速度,提出一种无握手机制的紧急消息的广播UHA-BEM(un-handshake and ACK broadcasting emergency message)方案。基于消息的信噪比SNR(signal-to-noise ratio)和节点位置计算竞争窗口(contention window sizes),从窗口内随机选择一个时隙,用于转发紧急消息,避免RTB(request to broadcast)/CTB(request to broadcast)握手机制。一旦收到重播的紧急消息,节点则不再重播该消息,此消息扮演抑制源节点再广播紧急消息作用,避免ACK确认环节。仿真结果表明,与智能广播SB(smart broadcast)相比,UHA-BEM方案每跳平均时延降低了200%,吞吐量提高了两倍。
To improve the transmission speed of emergency message of vehicle Ad hoc networks（VANETs）,a un-handshake and ACK broadcasting emergency message（UHA-BEM）scheme was proposed.Signal-to-noise ratio（SNR）and location information were used to compute the contention window sizes,and a time slot was randomly chosen from the contention window sizes to transmit the emergency message,which avoided the RTB（request to broadcast）/CTB（request to broadcast）handshake mechanism.Once the re-broadcasted emergency message was received,the node did not broadcast the emergency message again,which inhibited source node to broadcast urgent message indicators,and avoided the ACK.Simulation results show that the proposed algorithm performs 200% better than SB in terms of average per hop delay,and the throughput is improved twice than SB.
出处
《计算机工程与设计》
北大核心
2016年第10期2602-2607,共6页
Computer Engineering and Design
基金
河南省科技攻关计划基金项目(122102210430)
河南省教育厅科学技术研究重点基金项目(13A520786)
关键词
竞争窗口
紧急消息
广播
握手机制
车联网
contention window
emergency message
broadcasting
handshake mechanism
VANETs
