Selective Relaying Strategy for Vehicular Communication with Big-Vehicle Shadowing

Vehicle-to-Vehicle (V2V) communication is a core technology for enabling safety and non-safety applications in next generation intelligent transportation systems (ITS). However, the reliability of V2V communication may degrade drastically if the communication links are blocked by big vehicles. Message relaying is an effective approach to enhancing the communication reliability, and in this scenario, the big vehicles are the ideal candidates of the relay node due to their height advantages. However, extensive message relaying may consume excessive communication resources and lead to severe network congestion. To this end, we propose a selective message relaying strategy which sorts the messages received by the big vehicles according to their “importance” and the messages in front of the queue are relayed with higher priority. The proposed selective relaying strategy can be incorporated with various metrics of the messages and implemented efficiently at the relay node. As an illustrative use-case, we show that the “importance” of the messages can be simply characterized by the relative position between their generating cars and the relaying nodes when the packet delivery ratio (PDR) is the design objective. Numerical results show that the proposed selective relaying strategy based on relative distance metric can substantially enhance the overall PDR as compared with the random relaying strategy.