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Publish-Subscribe Communications for V2I Safety Applications in Intelligent Transportation Systems

Road situation awareness plays an essential role in road safety where the emerging Vehicle-to- Infrastructure (V2I) communications are used to issue safety messages to enable awareness among users. It is generally agreed the 4G mobile broadband services can support such V2I road applications. However, how well 4G mobile services can meet the requirements is less understood. In this paper, we propose 4G based V2I road data communication mechanism supporting publish- subscribe paradigm to multicast road safety messages according to the user location. In fact, we introduce advanced filtering method based on the travelling road and the heading direction of the users to filter the most relevant road events, not only limited to the conventional proximity based filtering. Thus communicating road event notifications to the most relevant road users through an infrastructure-less decentralized application layer system is the main focus of our work. A prototype system called "CoRES: Cooperative Road Event Sharing app" is developed to evaluate the approach using an actual on-the- road experiment showing that users can receive reliable notifications at low latency and high reliability.