Research On The Information Dissemination System Of Traffic Congestion Events In Vehicular Ad-Hoc Networks

With the continuous increase of residents’ car ownership,traffic congestion has become a common problem faced by many cities in the world.Therefore,the research on Traffic Congestion Event Information Dissemination System(TCEIDS)is increasingly urgent.TCEIDS relies on Vehicular Ad Hoc Networks to spread traffic Congestion information to alleviate traffic congestion and reduce the occurrence of secondary accidents.In TCEIDS,vehicles causing congestion or vehicles in a congestion risk area can collect potential traffic congestion information and generate a standardized Traffic Congestion Warning Message(TCWM),Through vehicle-to-vehicle interaction and vehicle-intersection interaction,etc.to pass TCWM to vehicles that may be driving into a Potentially Congested Area(PCA).With the help of TCEIDS,drivers can obtain the risk of traffic congestion beyond the visible range and make route changes in advance to avoid congestion.This article focuses on the design,modeling and implementation of TCEIDS.The specific research contents are as follows:1.The structure of TCWM is designed,and a multicast routing protocol(reverse routing protocol)suitable for TCWM propagation is proposed,in this protocol,the destination node is determined to be a vehicle driving to PCA in a specific area,which is upstream of the accident and consists of a limited number of intersections and road sections between them,the forwarding node is identified as a vehicle traveling upstream of the accident and away from the PCA.The performance of the reverse routing protocol was compared with the flood propagation protocol.The results prove that the reverse routing protocol has higher value.2.Designed the basic framework of TCEIDS,in this framework,the data packet used is TCWM,and the propagation protocol used is the reverse routing protocol;The interaction behavior of vehicles and intersections in TCEIDS is analyzed,It includes that when a vehicle in the congestion area detects the congestion information and generates TCWM,TCWM will be updated every time it passes the intersection,and will be considered to be forwarded every time the vehicle meets.3.CPN modeling was performed on the three interaction behaviors in TCEIDS,showing the process of TCWM formation,update and forwarding;and the analysis of the model’s state space,the results show that the model is bounded,deadlock-free,there is no conflict and every desired state can be achieved in the model.This model makes TCEIDS easier to understand and improve the design efficiency.It has a high reference value for the analysis,design and development of TCEIDS.4.Using the CPN model as a reference,TCEIDS was developed based on JADE.The specific contents include: designing and implementing an Agent class that can be run in on-board equipment,completing the update of TCWM when the vehicle agent meets the intersection agent,and transmit TCWM to each other when vehicles meet.