Roadside Units Deployment for Efficient Short-Time Certificate Updating in VANETs

Roadside Units (RSUs) aided distributed certificate service is a promising approach for ensuring security and privacy preservation in vehicular ad hoc networks (VANETs), where the existence of RSUs is critical for such a scheme in order to allow On-Board Units (OBUs) to update their short-time certificates on time. However, RSUs may only be deployed at some critical points along roads due to the cost. In this paper, we propose a cost-efficient RSUs deployment scheme to guarantee that OBUs at any place could communicate with RSUs in certain driving time (DT), and the extra overhead time (ET) of adjusting routes to update short-time certificate is small. Based on a real-world map, several deployment examples are given illustrating the influence of key factors in RSUs deployment such as wireless communication range, DT and ET. Furthermore, extensive analysis demonstrates that our RSUs deployment scheme can meet the required design goals.