I. Introduction
Cooperative services in vehicular scenarios are becoming essential for the future connected vehicle within the ITS (Intelligent Transportation Systems) research field. They are supposed to decrease road fatalities, improve the capacity of roads, diminish the carbon footprint of road transport and enhance the user experience during travels. Although there are many vehicular services envisioned for the short, medium and long term, these can be categorized in the next groups [1], [2]: safety, traffic efficiency and infotainment. Although many of these services have hitherto been proposed together with application-level protocols designed from scratch, this is not a scalable way of developing services within the same information system. With the exception of some services, such as multimedia or common Web access, many ITS services have common communication requirements:
Periodic status exchange. ITS services typically need to know about the status of vehicle or roadside terminals. This implies the periodic exchange of data packets with information about location, speed, identifier, etc.
Asynchronous notifications. This kind of messages are used to inform about a specific service event. In contrast to the previous status messages, the reliable delivery of these messages to a single terminal or a group of them is usually a key requirement.