Abstract
Local Dynamic Map (LDM) has been studied recently, with which cooperative ITS applications require to manage information based on objects such as vehicles, other objects, and roads. In LDM, information on a map are divided and layered into every feature. Although requirements of transmission delay differ in each layer of the defined map data, the current network technologies do not consider the situation and the transmission delay is increased. In this paper, we propose an efficient transmission method to approach the delay problem for all the transmission data with the increased data volume by using the position relativity of the data receiver automobile in inter vehicle communications and the difference of each layer’s characteristics and transmitting them, high-urgent data should be transferred as quick as possible, and even with low-urgent data they can be delayed, but transferred authentically. We also implement priority levels in the transfer data, and fulfill the band frequency assignments dynamically. Through the result of the evaluation of high and low vehicle density circumstances, we have confirmed that our proposed method is effective in high vehicle density circumstances.
