احمد علي حسين
Abstract
Autonomous vehicles are projected to dominate transportation, necessitating enhancements to Intelligent Transportation Systems (ITS) for efficient message transmission. VANET (Vehicular Ad-hoc Network) technology is becoming an integral part of intelligent transport systems, and message propagation enhancement is crucial for an efficient on-road communication system. However, message exchange among vehicles faces challenges due to varying communication conditions (e.g., interference) and dynamic topology changes with intermittent connectivity. Therefore, the proposed method will consider a methodology based on delay-tolerant networks (DTN). The proposed method is applied to two types of VANET: vehicle-to-vehicle communication and vehicle-to-roadside unit (RSU) using IEEE 802.11p. Moreover, performance metrics related to message connectivity assess the quality of service and average information delay. The findings of the proposed method can be applied to network planning in VANET-based ITS. Due to the highly dynamic topology and potential connectivity disruptions, the proposed method will store messages until the connection is re-established or alter the transmission path to choose an alternative route for sending the reminder message. The proposed method uses a greedy flooding control message-passing routing algorithm. It switches to perimeter forwarding mode if greedy forwarding fails and uses DTN for message transport if both modes fail. Utilizing NS2 simulations to assess the method and employing SOMU to generate road and vehicle movement, the results demonstrate an enhanced packet delivery ratio (PDR). For 20 vehicles, the PDR reaches 0.93, while for 100 vehicles, it attains 0.96. This improvement is attributed to the expansion of cluster size, which accommodates more message relay vehicles, consequently augmenting the probability of successful message delivery. Additionally, the end-to-end delay is reduced, indicating the proposed method's effectiveness in improving network performance in VANETs.
