This paper describes an indoor localization system based on RO-SLAM technique, which has been led to experimentation. The proposed system has been considered to have low power consumption. The nodes of the network are based on the well-known architecture TelosB. A distance estimation study has been developed in order to determine the relationship between radio power signal strength in a radio link and distance between nodes. This relationship has a high variability and given its importance for successful tracking, much of this work has been devoted to its study. This system could be applied as a usefull solution for localization in a warehouse, where GPS-based system does not work. Based on the results obtained, this system is deemed as feasible because the motes have been localized with an acceptable error (1.2 m) under real conditions.