As 5G new radio (NR) networks continue to be deployed, indoor positioning has emerged as one of the most sought-after applications. However, achieving indoor positioning accuracy comparable to outdoor positioning using radio access network (RAT)-dependent technology remains a subject of extensive research and investigation. This paper delves into the investigation of the TDOA-based positioning architecture and presents the formulation of the DL-TDOA measurement methodology. Furthermore, the study examines three environmental settings: Line-of-Sight (LOS) propagation and random LOS propagation in the outdoor environment, as well as Non-Line-of-Sight (NLOS) propagation in the indoor environment. The study reveals that the UE position estimation errors remain consistent outdoors, but they are twice as large in the indoor environment compared to the outdoor scenario.