基于网络编码的车联网信标广播方案研究

发布时间：2018-04-17 14:11

本文选题：车载自组织网络 + 信标　；参考：《南京邮电大学》2014年硕士论文

【摘要】：汽车持有量的不断增长,虽然在很大程度上便利了人们的日常出行和生活,但是交通堵塞和交通事故出现的频率也随之升高。为了解决这个难题,特别是为了确保道路行车安全,人们将目光转向了车载自组织网络(Vehicular Ad hoc Networks, VANETs)上。 VANETs中的应用分为两类：安全应用和增值应用。安全应用是为了改善道路行车安全,它需要在车辆间实时的交互一些与车辆安全相关的信息。这些信息主要分为两种：一种是车辆的状态信息,称为信标消息,信标消息是以周期性的广播发送出去的,对广播接收率、时效性以及公平性要求较高；另一种是由事件驱动的紧急报警消息。为了提高信标消息的广播接收率和覆盖范围,本文提出了一种基于行驶方向的网络编码重传算法(Direction-based Network Coded Repetition, DNCR。 DNCR中车辆节点通过采样可以估算出邻近节点信标消息的接收概率,再使用编码候选节点收集机制维护两个方向的候选节点权重表。车辆节点在转发时会从这两个权重表中分别选择一个权重最大的信标消息进行异或编码,这样选出的候选编码包是属于不同行驶方向的车辆节点,并且由此产生的编码包有很大的概率能够被解码。最后本文使用VanetMobiSim口NS-2.35仿真器对提出的DNCR算法进行仿真分析。并与已有的网络编码重传(Network Coded Repetition, NCR)算法和原始的IEEE802.11p协议进行对比分析,仿真结果表明DNCR算法在车辆密度不是很高时能够有效的提高广播接收率,并且DNCR算法所带来的网络负载要小于NCR算法。
[Abstract]:With the increasing of car ownership, traffic jams and traffic accidents appear more frequently, although it greatly facilitates people's daily travel and daily life.In order to solve this problem, especially in order to ensure road safety, people turn their attention to the vehicular Ad hoc Networks (VANETs).The application of VANETs is divided into two categories: security application and value-added application.Safety application is to improve road traffic safety, it needs to exchange some information related to vehicle safety in real time.These information are mainly divided into two types: one is the vehicle status information, called beacon message, the beacon message is sent out by periodic broadcast, which requires high broadcast reception rate, timeliness and fairness;The other is an event-driven emergency alarm message.In order to improve the broadcast reception rate and coverage of beacon messages, this paper proposes a direction-based Network Coded repeat algorithm based on driving direction.Vehicle nodes in DNCR can estimate the reception probability of beacons in neighboring nodes by sampling, and then maintain the weight table of candidate nodes in both directions by using the encode candidate node collection mechanism.When the vehicle node forwards, one of the most weighted beacon messages is selected from the two weight tables for XOR coding, so the candidate coding packet is a vehicle node with different driving directions.And the resulting coding packet has a high probability that it can be decoded.Finally, the VanetMobiSim port NS-2.35 simulator is used to simulate the proposed DNCR algorithm.Compared with the existing network coded retransmission network Coded replication (NCRR) algorithm and the original IEEE802.11p protocol, the simulation results show that the DNCR algorithm can effectively improve the broadcast reception rate when the vehicle density is not very high.And the DNCR algorithm brings less network load than the NCR algorithm.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U495;TN911.2

【共引文献】