Towards predictable vehicular networks

Communication primitives consider information delivery with different guarantees regarding their reliability. The provision of reliability and predictability needs to overcome a number of challenges with respect to failures and a number of known impossibility results. This chapter covers a number of these challenges in the context of vehicular systems and networks. We start by showing the medium access control (MAC) protocol for wireless mobile ad hoc networks can recover from timing failures and message collision and yet provide a predictable schedule in a time-division fashion without the need for external reference, such as commonly synchronized clock. We then consider the case of transport layer protocols and show how to deal with settings in which messages can be omitted, reordered and duplicated. We also consider how mobile ad hoc networks and vehicular networks can organize themselves for emulating virtual nodes as well as emulating replicated state-machines using group communication. In this context, we discuss the different alternatives for overcoming well-known impossibilities when considering cooperative vehicular applications. Finally, we exemplify applications and discuss their validation.