A Content-Based Publish/Subscribe System for Efficient Event Notification over Vehicular Ad Hoc Networks

Pub/Sub systems over VANETs can be employed to disseminate information in terms of events to vehicle users who desire the information. This paper describes the design, implementation, and evaluation of APUS, a content-based Pub/Sub system for VANETs. APUS can handle the subscriptions with complicated spatial-temporal constraints and forward the notifications to the specified areas so that vehicle users can pick up the notifications there. In regards to the implementation, APUS exploits RSUs (Road Side Units) to relay messages and match subscriptions with events. Simulation experimental results show that APUS achieves high delivery ratios and stable low costs in event notification no matter how the traffic statistics such as vehicle density and vehicle speed change.