Deep reinforcement learning-based forwarding node selection algorithm in Internet of vehicles

Due to open communication environment, Internet of Vehicles (IoV) are vulnerable to many attacks, including the gray hole attack, which can disrupt the process of transmitting messages. And this results in the degradation of routing performance. To address this issue, a double deep Q-networks-based stable routing for resisting gray hole attack (DOSR) is proposed in this paper. The aim of the DOSR algorithm is to maximize the message delivery ratio as well as to minimize the transmission delay. For this, the distance ratio, message loss ratio, and connection ratio are taken into consideration when choosing a relay node. Then, to choose the relay node is formulated as an optimization problem, and a double deep Q-networks are utilized to solve the optimization problem. Experimental results show that DOSR outperforms QLTR and TLRP by significant margins: in scenarios with 400 vehicles and 10% malicious nodes, the message delivery ratio (MDR) of DOSR is 8.3% higher than that of QLTR and 5.1% higher than that of TLRP; the average transmission delay (ATD) is reduced by 23.3% compared to QLTR and 17.9% compared to TLRP. Additionally, sensitivity analysis of hyperparameters confirms the convergence and stability of DOSR, demonstrating its robustness in dynamic IoV environments.