Scheduling temporal data for real-time requests in roadside-to-vehicle communication

Recent advances in wireless communication technologies have spawned many new applications in vehicular networks. Data dissemination via roadside-to-vehicle communication is a vital approach to enabling most of these applications. In this work, we investigate in the scenario where data items are broadcasted from the road-side unit (RSU) in response to requests submitted by passing vehicles. Data items are associated with temporal constraints and updated periodically to reflect dynamic states of traffic information. Each request may ask for multiple temporal data items, and it is associated with a deadline, which may either be specified by the driver or imposed by the time when the vehicle drives through the service region. In particular, we develop a real-time data dissemination model based on roadside-to-vehicle communication by formulating the time-constraint of requests and the consistency requirement of retrieving temporal data items. On this basis, we propose an online scheduling algorithm to enhance the system performance in terms of maximizing request service and improving bandwidth utilization. Lastly, we build a simulation model to evaluate the algorithm performance in a variety of situations. Experimental results demonstrate that the proposed algorithm outperforms existing algorithms significantly in both request serving and bandwidth utilization.