【摘要】：城市的發(fā)展為車載自組織網(wǎng)絡(luò)(vehicular ad hoc network,VANET)(也稱車聯(lián)網(wǎng))提供了廣闊的應(yīng)用空間,其中緊急消息廣播方法則是應(yīng)用的一個重點(diǎn)研究內(nèi)容.緊急消息廣播需要滿足低延遲、高可靠和高可擴(kuò)展性等服務(wù)質(zhì)量方面的要求.現(xiàn)有的緊急消息廣播方法在選擇下一跳轉(zhuǎn)發(fā)節(jié)點(diǎn)時(shí),假定每一個位置均有大致相等的概率被選為中繼區(qū)域,對所有位置的節(jié)點(diǎn)一視同仁,缺乏針對最優(yōu)節(jié)點(diǎn)位置分布規(guī)律的研究,不能較好地適應(yīng)最優(yōu)轉(zhuǎn)發(fā)節(jié)點(diǎn)的分布情況.而降低緊急消息傳播延遲的關(guān)鍵是快速確定合適的中繼轉(zhuǎn)發(fā)節(jié)點(diǎn).因此,為了進(jìn)一步提高緊急消息廣播的及時(shí)性,降低傳播延遲,提出一種采用類哈夫曼編碼的緊急消息廣播方法.首先分析了城市道路中最優(yōu)轉(zhuǎn)發(fā)節(jié)點(diǎn)的概率分布情況,然后在此基礎(chǔ)上利用哈夫曼編碼的原理,設(shè)計(jì)了一種能夠最小化最優(yōu)節(jié)點(diǎn)選取時(shí)間的快速分區(qū)方法,最終達(dá)到快速確定最優(yōu)中繼節(jié)點(diǎn),降低緊急消息廣播延遲,提高緊急消息傳播速度的目的.仿真實(shí)驗(yàn)證明:該方法在不同場景中能夠降低5.3%~18.0%的緊急消息廣播時(shí)延,提高8.9%~24.5%的緊急消息傳播速度.
[Abstract]:The development of the city provides a broad application space for the vehicle self-organizing network (vehicular ad hoc network,VANET (also known as the vehicle network), in which the emergency message broadcasting method is a key research content. Emergency message broadcasting needs to meet the quality of service requirements such as low delay, high reliability and high scalability. When the existing emergency message broadcasting method selects the next hop forwarding node, it is assumed that each location has an approximately equal probability of being selected as the relay area, and the nodes at all locations are treated equally. Lack of research on the optimal node position distribution law, can not adapt to the optimal forwarding node distribution. The key to reduce the delay of emergency message propagation is to quickly identify the appropriate relay forwarding node. Therefore, in order to further improve the timeliness of emergency message broadcasting and reduce the transmission delay, an emergency message broadcasting method based on Huffman-like coding is proposed. This paper first analyzes the probability distribution of the optimal forwarding node in the urban road, and then designs a fast partition method which can minimize the optimal node selection time by using the principle of Huffman coding. Finally, the optimal relay node can be determined quickly, the delay of emergency message broadcast can be reduced, and the speed of emergency message propagation can be improved. The simulation results show that this method can reduce the emergency message broadcast delay by 5.3% 鈮，

本文編號：2489903