The routing in vehicular delay tolerant networks (VDTNs) does not presume an end-to-end connectivity from source to destination. One substitute is to use the real-time geographical information of vehicles to relay messages. However, if mobile destination is considered, then real-time information might not be generally available due to the sparse network density in VDTN. In this paper, a geographical routing approach based on the probability delegation replication (GR-PDR) is proposed. The functionality of GR-PDR is categorized into forwarder node selection phase and buffer management phase. The forwarder node selection utilizes the advantages of delegation replication approach to conquer the constraints of routing decisions and local maximum problem. Further, the buffer management is employed to prioritize packets to ensure delivery before the expiration of message lifetime. The proposed GR-PDR ensures that the message will be forwarded to higher quality node, resulting in a high delivery ratio. The approach utilizes the advantages of single-copy and multiple-copy forwarding approaches by avoiding redundant replication and enhancing delivery probability, respectively. The performance results show that the proposed GR-PDR outperforms in terms of packet delivery ratio, average delay and network overhead, when compared with the protocols of the same segment. Statistical analysis validates the effectiveness of the proposed protocol.

中文翻译：

---

VDTN中基于概率委托复制（GR-PDR）的地理路由方法

车载延迟容忍网络 (VDTN) 中的路由不假定从源到目的地的端到端连接。一种替代方法是使用车辆的实时地理信息来中继消息。但是，如果考虑移动目的地，则由于 VDTN 中的网络密度稀疏，实时信息可能通常无法获得。在本文中，提出了一种基于概率委托复制（GR-PDR）的地理路由方法。GR-PDR 的功能分为转发节点选择阶段和缓冲区管理阶段。转发节点选择利用委托复制方法的优点来克服路由决策和局部最大值问题的约束。进一步，缓冲区管理用于对数据包进行优先级排序，以确保在消息寿命到期之前交付。提出的 GR-PDR 确保消息将被转发到更高质量的节点，从而实现高传递率。该方法分别通过避免冗余复制和提高传递概率来利用单副本和多副本转发方法的优点。性能结果表明，与同一段的协议相比，所提出的 GR-PDR 在数据包传递率、平均延迟和网络开销方面均优于其他协议。统计分析验证了拟议协议的有效性。该方法分别通过避免冗余复制和提高传递概率来利用单副本和多副本转发方法的优点。性能结果表明，与同一段的协议相比，所提出的 GR-PDR 在数据包传递率、平均延迟和网络开销方面均优于其他协议。统计分析验证了拟议协议的有效性。该方法分别通过避免冗余复制和提高传递概率来利用单副本和多副本转发方法的优点。性能结果表明，与同一段的协议相比，所提出的 GR-PDR 在数据包传递率、平均延迟和网络开销方面均优于其他协议。统计分析验证了拟议协议的有效性。