[论文解读] Bus Trajectory-Based Street-Centric Routing for Message Delivery in Urban Vehicular Ad hoc Networks

Gang Sun, Yijing Zhang+4 more|arXiv (Cornell University)|Apr 7, 2018

Vehicular Ad Hoc Networks (VANETs)参考文献 29被引用 8

一句话总结

该论文提出了一种基于公交轨迹的街道中心型路由（BTSC）算法，用于城市车辆自组织网络（VANETs），利用固定公交路线作为可靠的多跳中继。通过建模街道一致性概率（PSC）和路径一致性概率（PPC），BTSC选择高密度、低偏差的路径，并采用蚁群优化进行转发，相比现有方案实现了更高的交付率、更低的延迟以及更好的适应性。

ABSTRACT

This paper focuses on the routing algorithm for the communications between vehicles and places in urban VANET. As one of the basic transportation facilities in an urban setting, buses periodically run along their fixed routes and widely cover city streets. The trajectory of bus lines can be seen as a sub map of a city. Based on the characters of bus networks, we propose a bus trajectory-based street-centric routing algorithm (BTSC), which uses bus as main relay to deliver message. In BTSC, we build a routing graph based on the trajectories of bus lines by analyzing the probability of bus appearing on every street. We propose two novel concepts, i.e. the probability of street consistency (PSC) and the probability of path consistency (PPC) which is used as metrics to determine routing paths for message delivery. This aims to choose the best path with higher density of busses and lower probability of transmission direction deviating from the routing path. In order to improve the bus forwarding opportunity, we design a bus-based forwarding strategy with ant colony optimization (FACO) to find a reliable and steady multi-hop link between two relay buses in order to decrease end-to-end delay. BTSC makes the improvements in the selection of routing path and the strategy of message forwarding. Simulation results show that our proposed routing algorithm has a better performance in transmission ratio, transmission delay and adaptability to different networks.

研究动机与目标

• 为解决由于高移动性和车辆密度稀疏导致的城市 VANET 中消息传递不可靠的问题。
• 利用可预测、高频率的公交路线作为城市环境中稳定的通信中继。
• 设计一种以街道为中心的路由算法，基于公交可用性和轨迹一致性选择最优路径。
• 通过基于蚁群优化的转发策略，提高消息转发的可靠性并降低端到端延迟。

提出的方法

• 使用历史公交轨迹数据构建路由图，以建模街道级别的公交可用性。
• 将街道一致性概率（PSC）定义为衡量公交在街道路段上持续存在的可能性的指标。
• 引入路径一致性概率（PPC）以评估候选路径与整体公交流向的一致性。
• 采用基于公交的转发策略，利用蚁群优化（FACO）识别中继公交之间的可靠、低延迟多跳链路。
• 将 PSC 和 PPC 作为联合度量，优先选择公交密度更高、方向偏差更低的路由路径。
• 集成动态路径选择与自适应转发，以在不同网络条件下提升性能。

实验结果

研究问题

• RQ1 如何利用公交轨迹提升高移动性城市 VANET 中的路由可靠性？
• RQ2 哪些度量能够有效捕捉街道级网络中潜在路由路径的一致性和可靠性？
• RQ3 如何优化公交之间的多跳转发以最小化端到端延迟并提高交付成功率？
• RQ4 所提出的 BTSC 算法在交付率和延迟方面相较于现有路由方案的优越程度如何？

主要发现

• BTSC 算法在高移动性城市场景下相比传统 VANET 路由协议实现了更高的消息交付率。
• 由于使用了高密度公交路线和优化的转发路径，端到端延迟显著降低。
• PSC 和 PPC 度量的集成提高了路径选择的准确性，从而带来更稳定、可预测的路由性能。
• 基于 FACO 的转发策略通过选择方向偏差最小、公交可用性最高的多跳路径，增强了可靠性。
• 该算法在不同城市网络拓扑和交通条件下均表现出强适应性。
• 仿真结果证实，BTSC 在交付率和延迟方面均优于现有方案，尤其在车辆密度较低时表现更优。