Fault Tolerant Architecture for Infrastructure based Vehicular Networks

Abstract

Wireless vehicular communications have been a trending topic in the last few years, leading to the development of a complete set of new standards and the emergence of innovative vehicular applications. Despite the obvious benefits of vehicular networks, it has been a challenging issue to design dependable vehicu- lar communication systems. This is mainly due to the high speed mobility scenarios that are involved and the open nature of these networks. As a consequence, there are scalability problems with the proposed medium access control (MAC) methods under highly dense traffic environments. This results in large values for the end-to- end delay and for the probability of packet drops, compromising the reliability of vehicular communications. Besides that, there are few strategies to enhance fault- tolerance in vehicular systems, whose operation strongly depends on the dynamic topology of the network and on the real-time guarantees provided by the communic- ations protocol. Based on these arguments, this chapter presents a fault-tolerant ar- chitecture to improve the dependability of infrastructure-based vehicular networks. The presence of road-side units (RSUs) and a backhauling network adds a degree of determinism that is useful to enforce real-time and dependability, both by providing global knowledge and supporting the operation of collision-free deterministic MAC protocols. One of such protocols is V-FTT, for which the proposed architecture was designed as a case study. Notice, however that this architecture is protocol inde- pendent and can be adapted to any wireless communications system. The chapter’s final sections specially focus on the design of fail silent RSUs, by presenting the purposed implementation and the obtained experimental results.