Design And Implementation Of An Efficient Broadcast Protocol For ITS Safety Application

With the popularity of vehicles and the development of mobile Ad-Hoc Networks technology, VANET (Vehicle Ad Hoc Network) has been a popular research field. Meanwhile, ITS (Intelligent Transport System) has also become a hot topic in the traffic area all around the world.IEEE 802.11p (also referred as WAVE, Wireless Access in the Vehicular Environment) is a new wireless communication protocol used in ITS. Compared with the traditional ones, WAVE provides the fast-moving vehicles with more reliable communication services and a data transfer rate up to 27Mbps within the 1000-meter communication range.Safety application which improves the traffic safety is one of the most important and basic ITS applications. And it always propagates warning messages in multi-hop broadcast, as the target is often a group of nodes rather than a single one.The well integration of WAVE and safety application may have positive effects on the development of the whole ITS industry and enable the drivers to enjoy higher safety.Therefore, this article proposes a novel On-demand Virtual Backbone Broadcast Protocol (OVB-CAST) for ITS safety application based on WAVE architecture. It can not only mitigate the broadcast storm and also transmit the messages to all the nodes with low delay as possible as it can. Besides, it has the function of load balancing.Having well studied the NCTUns simulator and the architecture of the protocol module, we develop a new protocol module using the NCTUns APIs to implement the OVB-CAST.Finally, we prove the correctness of our implementation of the OVB-CAST in a simple simulation scenario. Then we compare OVB-CAST with Flood in another simulation scenario, and show its high performance and adaptation for ITS safety application by a group of evaluation criteria.