An economical, deployable and secure vehicular ad hoc network

With the significant development of wireless technologies, vehicular ad-hoc network (VANET) has gradually become the killing application for automobile industry. Many VANET systems have been developed in recent years. However, the majority of them have the assumption that all or most vehicles have wireless communication devices installed along with an elaborate road side infrastructure. This assumption is not true for the critical and long transition period when only a small portion of vehicles will be equipped with wireless communication devices (we refer them as smart vehicles) and limited roadside infrastructure will exist. In this paper, we present an economical, scalable and deployable VANET system design that could facilitate the gradual deployment of wireless communication among vehicles. Economical roadside service units (RSSU) that do not need expensive Internet access (especially in rural areas) can be incrementally deployed along critical road sections. They behave as traffic information storage and relay points to serve any passing by smart vehicles, while smart vehicles report/receive traffic information to/from RSSUs and relay information between RSSUs. In addition, RSSUs provide strong but economical information assurance to VANET similar to the public-key base Internet Web service-RSSUs behave like Web servers with certificates and vehicles behave like client computers. In this way, the mature Internet-like public-key infrastructure can be directly deployed in VANET without requiring digital certificate for every smart vehicle, which is complicated to manage and very expensive considering the huge vehicular population. We show that we can achieve connectivity with a high degree of confidence with a small number of smart vehicles and few RSSUs.