Design and Evaluation of Intervehicle Dissemination Protocol for Propagation of Preceding Traffic Information

In this paper, we propose an intervehicle information dissemination protocol called received message-dependent protocol (RMDP) that propagates the preceding traffic information to the following vehicles and discuss its performance. The proposed protocol autonomously changes the dissemination interval, depending on the number of reception messages and detected reception errors, in order to avoid message collision among vehicles. We have constructed a realistic simulation environment of intervehicle communication by combining a traffic-flow simulator and an ad hoc network simulator. Our simulation results show that, by using RMDP, a lot of vehicles can acquire their preceding traffic information within short periods at both the conditions with light and heavy traffic. In addition, we have also shown that selection policy of disseminated data affects preceding-traffic-information acquisition time. Each vehicle holds other vehicles' traces for some period. Depending on the number of preserved other vehicles' traces and their preserved periods, the propagation ratio of the preceding traffic information varies. Some simulation results are explained.