Architecture of a communication middleware for VANET applications.

As one of the main tasks of a project for developing an Advanced Cooperative Infomobility System (ACIS), we have devised and partly implemented a communication middleware for infomobility applications on vehicular ad-hoc networks (VANETs). Our VANET is a wireless nework established by the cars themselves, with support from a number of fixed roadside units. Both cars and roadside units are equipped with computing resources, wireless networking, and positioning devices. One of the main goals of the ACIS project is to turn each moving car into a sophisticated mobile sensor, able to report about various phenomena including traffic and road conditions. The sensed data are to be collected through the VANET and feed a remote application for traffic prediction and control. The ACIS communication middleware, called ACME (ACis Middleware for Emerging vanet applications), is broadly based on a publish-subscribe paradigm implemented according to a peer-to-peer distributed organization relying upon the vehicular network. In this paper we illustrate and motivate the architectural choices underlying the ACIS middleware. This work has been carried out within the project ACIS, which is partly funded by the Italian Ministry of Education and Research.