What is TWR?

TWR (Two Way Ranging) is an algorithm for two-way ranging. First, the tag transmits a signal to the anchor. The anchor receives the signal and then returns it to the tag. Finally, the tag sends a receipt of the data to the anchor. The anchor calculates the distance between the anchor and the tag by averaging the time the radio waves took to travel three times between the anchor and the tag (tag à anchor à tag à anchor).