Broadcasting geographic information with levels-of-details to moving objects

In recent years, broadcast data delivery has been studied well with the spread of mobile terminals. In order to realize efficient data distribution, we have proposed a technique to group moving objects with respect to not only their positions, but also their direction and speeds. This paper aims at further improvements in the efficiency of information distribution by introducing the concept of LoD (levels of details) into broadcast data. Specifically, the geographic data are distributed with distinct granularities depending on distances between the data and moving objects. This is realized with the combination of source data written in XML and accompanying transformation scripts that extract coarse data from the source data. The proposed scheme makes it possible to lower the amount of transmitted data. Furthermore, we propose two algorithms for scheduling broadcast geographic data; One is based on speeds of moving objects, and the other is based on continuity of geographic data.