Among the solutions for indoor real-time locating systems (RTLS), the use of ultra-wide-band (UWB) ranging is indispensable. However, the common approach of the existing system in literature, require three or more reference points to determine the position of a tag. It will consume significant power and costly for the large-scale implementation. In this paper, we presented our initial work, a design of indoor RTLS by use of the UWB TOA-based algorithm with only two sensor nodes as the references from a set of 802.15.4a WSN positioning scheme. In order to determine the position of a tag, we selected the minimum distance between the initial tag position and estimated tag positions resulted in the intersection between two reference points. The evaluation shown root mean square error of estimation is about 12.79 cm and 22.26 cm within the R95 accuracy. It is shown that our approach is feasible to be implemented.