A Trajectory-Driven Opportunistic Routing Protocol for VCPS

By exploring sensing, computing, and communication capabilities on vehicles, vehicular cyber-physical systems (VCPS) are promising solutions to provide road safety and traffic efficiency in intelligent transportation systems. Due to high mobility and sparse network density, VCPS could be severely affected by intermittent connectivity. In this paper, we propose a trajectory-driven opportunistic routing (TDOR) protocol, which is primarily applied for sparse networks, e.g., delay/disruption tolerant networks (DTNs). With geographic routing protocol designed in DTNs, existing works primarily consider the proximity to destination as a criterion for next-hop selections. Differently, by utilizing GPS information of on-board vehicle navigation system to help with data transmission, TDOR selects the relay node based on the proximity to trajectory. This aims to provide reliable and efficient message delivery, i.e., high delivery ratio and low-transmission overhead. TDOR is more immune to disruptions, due to unfavorable mobility of intermediate nodes. Performance evaluation results show TDOR outperforms well-known opportunistic geographic routing protocols, and achieves much lower routing overhead for comparable delivery ratio.