A study of Multi-Priority Opportunistic Directional Routing for VANET

In Vehicular Ad-hoc Network (VANET), the multi-hop routing frequently breaks off, which has a negative effect on the reliability and transmission quality of the network. The paper proposes a new routing algorithm based on the geographical position, called Multi-Priority Opportunistic Directional Routing (MPODR). The algorithm improves the existing Opportunistic Directional Forwarding Strategy from two aspects. Moreover, it works together with 802.11p protocol, and adds a strategy to process the security alarm packets with high-priority, which makes the algorithm reliable and efficient. We compare the performance of GPSR and MPODR using network simulator NS2, with a specialized node mobility model simulator called VanetMobiSim to produce realistic vehicular movement trace. In the simulation, MPODR shows a much better performance than GPSR, the packet loss rate is reduced by about 80%, and the delay of the high-priority packet is within 300ms. As a result, MPODR is more suitable for vehicular network.