“…Both groups assume that a set of tags storing the absolute positional information are deployed throughout a navigation environment. In one group, either active or passive tags are installed along the wall and they are used as beacons or landmarks to guide the navigation of a mobile robot (Kubitz, O., et al, 1997;Kantor, G., et al, 2002;Hahnel, D., et al, 2004;Kulyukin, V., et al, 2004;Penttila, K., et al, 2004;Yamano, K., et al, 2004;Kim, B.K., et al, 2006;Vorst, P., et al, 2008). However, in the other group, passive tags are installed on the floor and they are used to indicate the current position of a mobile robot (Bohn, J., et al, 2004;Choi, J., et al, 2006;Kim, B.K., et al, 2006;Han, S., et al, 2007;Kodaka, K., et al, 2008).…”