Message reply method by making use of node location advertisement in VANET

In late years, the ITS which aims at improvement of convenience and the comfort in the road traffic using an information technology attracts attention, and service to deliver useful information quickly by communication among vehicles is flourishing research area. However, vehicles may be distributed sparsely by traffic conditions in VANET, and it is difficult to maintain stability of the communication. Therefore, DTN technology that communication is enabled by permitting a delay even if vehicles are distributed sparsely can be applied in such an environment. However, a delay occurs for the delivery of data when I apply DTN environment. Therefore, it becomes difficult to deliver a reply message to the requesting vehicle due to movement of the vehicle before message arrival. For such a problem, we aim at the arrival rate improvement of the reply message by while the requesting vehicle waits for a reply, advertising the own position on neighboring appropriate vehicles. Then, we evaluated our method which distribute an advertisement to vehicles nearby and suggested the method using the flooding and the method using geocast. We investigated that an arrival rate of the reply message is improved by our proposed method by computer simulation.