车载自组织网络中基于地理位置的路由协议研究

发布时间：2018-07-07 17:11

本文选题：车载自组织网络 + 路由协议　；参考：《南通大学》2016年硕士论文

【摘要】：车载自组织网络是一种特殊的移动自组织网络,其独有的特点包括车速变化快、网络拓扑变化快、车辆沿道路行驶等。基于无线设备的特点,通信模型被分成两种类型:车与车之间的通信和车与路边基础设施之间的通信。作为智能交通系统的关键部分,车载自组织网络提供大量的应用,可以分为娱乐应用和安全应用。尽管这种网络场景下的路由协议已经被广泛的研究过,但是在地理位置路由协议中仍有很多问题需要去解决。本文针对基于地理位置的路由协议做了详细的研究。首先,为了解决由于道路上车辆密度快速变化,而传输半径却保持不变所带来的不稳定的连通性和较高的误比特率,提出一种基于车辆密度的可变传输范围路由(VRR)协议,节点根据道路车辆密度调节信息最大传输距离,降低信息传输时延,确保网络的高连通性。我们采用齐次的泊松点过程模型进行研究,在此基础上推导出传输半径与车辆密度之间的变化关系,通过理论分析得到平均时延的数学表达式,最后利用仿真软件将VRR协议与固定传输范围路由(FRR)协议的性能进行了详细的比较。仿真结果表明VRR协议能够应用到实际环境中,且在整个网络连通性很高的条件下,将数据分组快速地转发到目的节点。其次,数据分组在转发过程中需要在其转发范围内寻找一个中继节点进行转发,为了降低转发过程中寻找中继节点的复杂程度,使源节点和目的节点之间链路的平均跳数得到降低,提出一种基于定向传播的自适应路由协议(ARPBDT)。该路由协议有两个关键参数:转发角度和平均每跳前进距离。首先为了缩小转发范围,设置一个始终朝着目的节点方向的转发角度,从而减小转发范围内节点数以及寻找中继节点的计算量;其次为了减小平均跳数,在转发范围内根据前进距离自适应地选择较优或次优的邻居节点作为中继节点进行转发。仿真结果表明与OBDR相比,所提路由协议的平均跳数较少,平均每跳前进距离较大,能够使数据分组快速地到达目的节点。最后,为了降低转发节点在转发范围内直接寻找一个最优或次优节点的复杂度,减少平均跳数,以及使路径的可靠性得到很大的提高,提出一种基于车辆密度的可靠性路由协议(RRPBVD),转发节点首先根据道路车辆密度设置最优区域块的大小,并将转发范围分割成若干大小相等的区域块,然后选择其中一个距离转发节点最远的区域块,最后在被选中的区域块里根据可靠性原则选择连接时间最长的邻居节点作为中继节点进行转发。仿真结果表明与EG-RAODV相比,所提路由协议的平均跳数较少,平均每跳前进距离较大,能够使数据分组快速地到达目的节点。
[Abstract]:The vehicle-mounted ad hoc network is a special mobile ad hoc network. Its unique characteristics include fast speed change, fast network topology change, and vehicle driving along the road. Based on the characteristics of wireless devices, the communication model is divided into two types: vehicle-to-vehicle communication and vehicle-to-road infrastructure communication. As a key part of intelligent transportation system, vehicle-borne ad hoc networks provide a large number of applications, which can be divided into entertainment applications and security applications. Although the routing protocols in this network scenario have been widely studied, there are still many problems to be solved in geographical routing protocols. In this paper, the geographical location based routing protocol is studied in detail. First of all, in order to solve the unstable connectivity and high bit error rate caused by the rapid change of vehicle density on the road while the transmission radius remains constant, a variable transmission range routing (VRR) protocol based on vehicle density is proposed. The node adjusts the maximum information transmission distance according to the road vehicle density, reduces the information transmission delay, and ensures the high connectivity of the network. On the basis of the homogeneous Poisson point process model, the relationship between the transmission radius and the vehicle density is derived, and the mathematical expression of the average delay is obtained by theoretical analysis. Finally, the performance of VRR protocol and fixed range routing (FRR) protocol is compared in detail with simulation software. The simulation results show that the VRR protocol can be applied to the real environment, and under the condition of high network connectivity, the data packets can be quickly forwarded to the destination node. Secondly, in order to reduce the complexity of searching for relay nodes in the process of forwarding, the data packet needs to find a relay node within its forwarding range to forward. The average number of hops between the source node and the destination node is reduced. An adaptive routing protocol (ARPBDT) based on directional propagation is proposed. The routing protocol has two key parameters: forwarding angle and average forward distance per hop. First of all, in order to narrow the forwarding range, we set a forwarding angle that is always oriented to the destination node, so as to reduce the number of nodes in the forwarding range and the amount of calculation to find the relay node; secondly, to reduce the average number of hops, According to the forward distance, the best or sub-optimal neighbor nodes are adaptively selected as relay nodes in the forwarding range. Simulation results show that compared with OBDR, the proposed routing protocol has less average hops and a larger average forward distance per hop, which enables the data packets to reach the destination node quickly. Finally, in order to reduce the complexity of searching for an optimal or sub-optimal node directly in the forwarding range, reduce the average number of hops, and improve the reliability of the path greatly. A reliability routing protocol based on vehicle density (RRPBVD) is proposed. The forwarding node first sets the optimal area block size according to the road vehicle density, and divides the forwarding range into several equal area blocks. Then select one of the region blocks farthest away from the forwarding node and select the neighbor node with the longest connection time as the relay node according to the reliability principle in the selected area block. The simulation results show that compared with EG-RAODV, the proposed routing protocol has less average hops and a larger average forward distance per hop, which enables the data packets to reach the destination node quickly.
【学位授予单位】：南通大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN929.5;U495

【相似文献】