Dynamic Feature of the Reserve Margin Space for Broadcast Storm Mitigation in VANETs

摘要

The necessity to improve safety measures and reduce accident risks on public roads has led to the development of the Wireless Access in Vehicular Environment (WAVE) technology. This has become a prominent and efficient candidate for future vehicular communication. In a view to achieve its main objective under the WAVE standard, all vehicular nodes (VNs) involved should exchange safety messages at the rate of 1 to 10 Hz, depending upon the congestion state of the network. However, during peak hours, when several VNs are in the same vicinity with any one of them broadcasting at the prescribed rate, a phenomenon known as Broadcast Storm (BSt) occurs - and this exhausts the available channel bandwidth making future transmission and reception uncertain. To mitigate BSt, the Improved Dynamic Broadcast Storm Mitigation Algorithm (IDBSMA) was proposed, and caters for both Cooperative Awareness Messages (CAMs) and Decentralized Environmental Notification Messages (DENMs) continuously. The proposed IDBSMA approach was tested by simulation under two scenarios. The results demonstrated that IDBSMA outperformed the DBSMA algorithm in three areas, namely: broadcasting delay, performance within the preset range, and in terms of the Reserved Margin Space (RMS) accounting for the DENMs messages. Accordingly, a strong motivation for IDBSMA is given and this paper ends with further work recommendations that are needed to take this technology further.