Resumen
A Vehicular Adhoc Network (VANET) is a generic conceptualisation that can be applied to the communications domain of an Intelligent Transportation Systems (ITS). It defines requirements that allow the exchange of information between applications and services running on equipment that form a VANET, mainly moving vehicles, fixed road infrastructure's systems and mobile personal devices. In this unique and demanding environment, interoperability is attained through the use of specific wireless communications technologies and protocols which have been addressed by several international standardisation organisations in an effort to boost the development of applications that could help users in very important application areas such as traffic safety and efficiency, infotainment and personal comfort. The great heterogeneity on the capabilities of the interconnected devices, the scale of the number of devices that could be involved, the various degrees of density and the complexity on the mobility patterns, makes interoperability at the application level a challenging problem.Apart from the technical restrictions imposed by those specific technologies, standard communications architectures for ITS present additional limitations due to the strategy used to access the communications technologies inside an ITS station, which is based on classic routing and switching mechanisms, signalling methodologies and facilities middle-ware layers. They also lack important implementation details for deployment of collaborative applications in real-world heterogeneous scenarios, favouring the development of these applications in a closed ecosystem, mainly dominated by the automotive industry leaders.This paper presents an agnostic VANET architecture, adapted from ETSI and ISO modern standards, to be deployed on ITS as a mean to overcome those limitations. This new approach permits the use of different communication technologies and network/transport protocol stacks in an open and modular framework, facilitating the creation of ITS cooperative applications and services, using traditional network programming paradigms where applications use the available medium transparently.The proposed architecture and its design principles have been used during the development, implementation and deployment of a Platooning application that the authors have developed on top of commercially available On Board Units.