Fig. 2.

An illustration of a face-to-face interaction measured with RFID badges. In this example, badge B detects the signal from badge A and sends the information to the RFID reader that then passes that information on to the server computer. The time of the interaction together with the information that badges A and B are interacting is recorded. Details on the tests determining the distance and angle for signal detection between two badges can be found in “Pretests”