A Moving Point Indexing Using Projection Operation for Location Based Services*

The progress of wireless communication technology causes to increase the concerns about contents services related to locations of mobile users. Objects in the LBS move freely and change their position and/or shape continuously over time. And it would be difficult to rapidly provide the moving object location to the mobile user. In order to efficiently process this information, we propose a MP-tree(short for Moving Point Tree) using the projection operation, which is an indexing technique for moving point data. The projection operation extracts the common boundaries of child nodes and stores the boundaries into the projection storage of all axes, so each of the projection storage has the aligned boundaries of subordinate nodes. The ordered boundaries of each projection storage are effective in not only processing moving object query such as point and range queries but also having smaller storage space and less cost of split, because they reduce unnecessary search nodes for overlap and dead space as well as the number of non-leaf nodes. Moreover the MP-tree is able to process combined trajectory queries effectively using linked list. The proposed MP-tree would be useful in the car management using GPS, and the navigation system for LBS.