A Publish/Subscribe Communication Infrastructure for VANET Applications

Vehicular Ad-hoc Network (VANET) can be envisaged as the network of moving vehicles communicating in asynchronous and autonomous fashion. Efficient and scalable information dissemination is a major challenge due to the movement of vehicles which causes unpredictable changes in network topology. Publish/Subscribe communication paradigm provides decoupling in time, space and synchronization between communicating entities, making it most suitable for VANET like environments. In this paper, we propose our publish/subscribe framework for information dissemination in VANET. In our approach, we assumed a hybrid VANET consisting of stationary info-stations and moving vehicles where each vehicle can take the role of publisher, subscriber or broker. Every major crossing of city is equipped with stationary info-stations that act as ultimate place holders for publications and subscriptions. These info-stations are assumed to be connected to internet and form Distributed Hash Table (DHT) based broker overlay among themselves. They act as rendezvous point for publications and subscriptions and send matching publications to interested subscribers. Further, these info-stations also provide services for locating any vehicle in the network. Simulation results indicate that our approach performs well with increasing number of vehicles which suggests the applicability of our approach.