ISSN 1000-1239 CN 11-1777/TP

计算机研究与发展 ›› 2017, Vol. 54 ›› Issue (11): 2475-2486.doi: 10.7544/issn1000-1239.2017.20170368

所属专题: 2017车联网关键技术与应用研究专题

• 网络技术 • 上一篇    下一篇

基于类哈夫曼编码的紧急消息广播方法

吴黎兵1,2,范静2,王婧2,聂雷2,王浩3   

  1. 1(软件工程国家重点实验室(武汉大学) 武汉 430072); 2(武汉大学计算机学院 武汉 430072); 3(岩土力学与工程国家重点实验室(中国科学院武汉岩土力学研究所) 武汉 430072) (wu@whu.edu.cn)
  • 出版日期: 2017-11-01
  • 基金资助: 
    国家自然科学基金项目(61472287,61572370,61772377);湖北省自然科学基金重点项目(2015CFA068);武汉市科技计划项目(2016060101010047)

Emergency Message Broadcast Method Based on Huffman-Like Coding

Wu Libing1,2, Fan Jing2, Wang Jing2, Nie Lei2, Wang Hao3   

  1. 1(State Key Laboratory of Software Engineering (Wuhan University), Wuhan 430072); 2(Computer School, Wuhan University, Wuhan 430072); 3(State Key Laboratory of Geomechanics and Geotechnical Engineering (Institute of Rock and Soil Mechanics, Chinese Academy of Sciences), Wuhan 430072)
  • Online: 2017-11-01

摘要: 城市的发展为车载自组织网络(vehicular ad hoc network, VANET)(也称车联网)提供了广阔的应用空间,其中紧急消息广播方法则是应用的一个重点研究内容.紧急消息广播需要满足低延迟、高可靠和高可扩展性等服务质量方面的要求.现有的紧急消息广播方法在选择下一跳转发节点时,假定每一个位置均有大致相等的概率被选为中继区域,对所有位置的节点一视同仁,缺乏针对最优节点位置分布规律的研究,不能较好地适应最优转发节点的分布情况.而降低紧急消息传播延迟的关键是快速确定合适的中继转发节点.因此,为了进一步提高紧急消息广播的及时性,降低传播延迟,提出一种采用类哈夫曼编码的紧急消息广播方法.首先分析了城市道路中最优转发节点的概率分布情况,然后在此基础上利用哈夫曼编码的原理,设计了一种能够最小化最优节点选取时间的快速分区方法,最终达到快速确定最优中继节点,降低紧急消息广播延迟,提高紧急消息传播速度的目的.仿真实验证明:该方法在不同场景中能够降低5.3%~18.0%的紧急消息广播时延,提高89%~24.5%的紧急消息传播速度.

关键词: 车联网, 多跳广播协议, 紧急消息分发, 干扰帧, 哈夫曼编码

Abstract: The development of urban city greatly promotes the application of vehicular ad-hoc network, among which the safety-related emergency message broadcast is one of the key research points. The emergency message broadcast needs to meet the requirements for the quality of service such as low latency, high reliability, high scalability and so on. Most existing emergency message broadcasting methods, when selecting the next hop forwarding node, assume that there is an approximately equal probability of being selected as the relay area for each location, and the nodes of all positions are treated equally, which lacks the study of the distribution of the optimal node position so that it cannot adapt well to the distribution of the optimal forwarding node. However, the key to reducing the delay in emergency messaging is to quickly determine the appropriate relay forwarding node. Therefore, in order to further improve the timeliness of emergency message broadcasting and reduce the propagation delay, in this paper, we propose a Huffman coding-based emergency message broadcasting method. Generally, we first analyze the probability distribution of the optimal forwarding nodes in urban roads. And based on it, we then use the principle of Huffman coding to design a fast partition method, which can achieve the goals of quickly selecting optimal relay node, reducing the delay of emergency message broadcast, and improving the speed of emergency message transmission by minimizing the optimal node selection time. Our simulation results show that the proposed method can reduce the delay of emergency message broadcasts in different scenarios by 5.3%~18.0%, and improve the speed of emergency message transmission by 8.9%~24.5%.

Key words: vehicular ad hoc network, multi-hop broadcast protocols, emergency message dissemination, black-burst, Huffman coding

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