A System Architecture for Ubiquitous Tracking Environments - Huber, Manuel; Pustka, Daniel; Keitler, Peter; Echtler, Florian; Klinker, Gudrun (2007 6th IEEE and ACM International Symposium on Mixed and Augmented Reality, Mixed and Augmented Reality, 2007. ISMAR 2007. 6th IEEE and ACM International Symposium on, 2007)