Development of a Roadside Unit Middleware for Vehicular Ad-Hoc Network Based Intelligent Transportation Systems

Vehicular Ad-hoc Networks (VANETs) are an emerging technology used to construct wireless networks among vehicles and between vehicles and roadside units (RSUs) for Intelligent Transportation Systems (ITS). In this paper, an RSU middleware which supports communication with on-board units (OBU) and a cloud center is proposed, and several core modules are implemented, including communication management, traffic policy management, and remote management modules. The RSU can control the traffic signals according to current traffic conditions and be managed by a remote client, it can also provide an early warning to drivers via the traffic event identification and warning system, and thus perform rerouting to avoid traffic congestion. The proposed RSU middleware is implemented on Linux and tested on a PC, and deployed to an embedded development board. The performance evaluation results show that the RSU middleware can concurrently handle more than 5,000 (simulated) OBUs, and it works well in a stability test for more than one month while handling more than 100 (simulated) OBUs per second. The proposed RSU middleware is an open source framework, which allows developers to customize it for more VANET-enabled ITS applications.