To measure distance three messages needs to be exchanged. The Tag initializes TWR by sending Poll message to known address of Anchor in time referred to TSP (Time of Sending Poll). The Anchor records time of Poll reception (TRP) and replies with the Response message at time TSR. The Tag upon reception of Response message records time TRR and composes Final message, where its ID, TSP, TRR, TSF information are included. Based on time reception of Final message TRF and information provided in the Final message the Anchor can determine the Time of Flight of UWB signal. Optionally, the resulted distance can be send within the Report message back to Tag or any given UWB device in neighborhood. The experiment show that optimal distance between Tag and Anchor for TWR process is in range of 20-30 meters.