【作者】 王二宝；

【导师】 李红艳；

【作者基本信息】 西安电子科技大学 ， 控制理论与控制工程， 2007， 硕士

【摘要】 随着无线通信技术的发展,配备了无线收发装置的车辆越来越多,于是出现了车辆与车辆之间的通信和车辆与路边单元之间的通信。车辆之间的通信类似于ad hoc网络,因此称之为车辆ad hoc网络(VANETs),这种VANETs与无线移动自组织网络相比既有共同点,又有很多的不同之处,特别是自组织网络中的广播技术并不完全适合车辆网络报警数据的广播。在众多的车辆网络的应用中,用于车辆安全的报警信息分发是至关重要的,本文就车辆网络中报警数据分发技术进行了深入的讨论。首先,本文介绍了自组织网络中广播技术和专用短距离通信标准DSRC,分析了车辆网络环境中报警数据分发的要求。其次,当事故范围较小时,单跳的报警数据分发技术能够满足安全要求。根据这一事实,在总结最新技术的基础上,提出了一种自适应报警数据的分发策略,该策略能够提高报警数据发送的可靠性,并且减少报警数据的延迟。最后,本文分析了基于多跳的报警数据转发环境中所存在的转发冲突问题,在此基础上提出了一种基于802.11广播的报警数据分发策略,该策略中的分组转发时间随着网络局部节点密度变化而自适应地变化,仿真结果表明该策略可以减少分组转发的延迟时间。更多还原

【Abstract】 With the development of wireless communication technologies, there are more and more vehicles equipped with wireless communication instruments. Then wireless communication among vehicles and between vehicles and roadside infrastructure appear. Wireless communication among vehicles is similar to ad hoc networks, thus, it is also called as VANETs. Otherwise among vehicles is not entirely equal to ad hoc networks. Especially, broadcast technology in the ad hoc networks not adapt to warning message broadcasting in the VANETs.Safe application is the most important among the applications of the VANETs. Thus, this paper thoroughly discusses warning data dissemination in the VANETs.First, this paper introduces broadcast technology in the ad hoc networks and the standard of dedicated short range communication (DSRC) and analyzes the demand of warning data dissemination in the VANETs.Second, single-hop can meet to the demand of warning data dissemination while scope of accident is small. According to the fact, the paper proposed a strategy of adaptive warning data dissemination on the basis of summarizing the newest technology. The strategy can enhances reliability and reduce delay of warning data packets.Finally, the paper analyzes the collision problem of rebroadcast that exists in the environment of forwarding warning data based on multi-hop. On the basis of the foregoing analysis, the paper proposed a strategy of warning data dissemination that based on 802.11 broadcast in the VANETs. Packet forwarding time of the strategy changes adaptively with local node density in the VANETs. Simulation results show that the strategy can reduce packet forwarding the delay time.更多还原