5.3.8 UWB Communication

The UWB communication functionality can be tested using the CARS PC application running on the host PC as follows:

  1. If not done already, follow the procedure detailed in CARS Kit PC Evaluation Utility.
  2. If not done already, follow the calibration procedure detailed in Fob Calibration Process .
  3. Position the fob at the desired distance from the base station hardware that will be used for the fob’s relay attack threshold.
  4. Navigate to View > PEPS Messaging to open the PEPS Message Status window (see Figure 5-7).
  5. Select the Unilateral Authentication radio option, click the Unlock button and, after the authentication sequence completes, note the value of the number in the “TOF Measured (cm)” field of the PEPS Message Status window. Enter this value in the “Relay Attack Threshold (cm)” field of the System Configuration window (see Figure 5-18).
  6. Move the fob closer to the base station hardware.
  7. Select the Unilateral Authentication radio option, click the Unlock button within the PEPS Message Status window to execute the unilateral authentication sequence.
    Note: The “LF Encrypted Challenge” field is not populated as this data is not transmitted to the fob.

    For example, the results of a PEPS unilateral authentication sequence display (see the following figure). With the “Relay Attack Threshold (cm)” as 20 cm and the measured value distance scale, “TOF Measured (cm)” as 19 cm, the system is not experiencing a relay attack; therefore, no Relay Attack icon is displayed.

    Figure 5-21. PEPS Unilateral Authentication with No Relay Attack Icon
  8. Move the fob further away from the base station hardware, beyond the location used in step 3 but still within the UWB operating range.

  9. Select the Bilateral Authentication radio option, then click the Unlock button within the PEPS Message Status window to execute the bilateral authentication sequence. Confirm that the “LF Encrypted Challenge” field is now populated.

    For example, the results of a PEPS bilateral authentication sequence display (see the following figure). With the “Relay Attack Threshold (cm)” as 20 cm and the measured value distance scale, “TOF Measured (cm)” as 34 cm, the system is experiencing a relay attack; therefore, the Relay Attack icon displays.

    Figure 5-22. PEPS Bilateral Authentication with Relay Attack Icon
Note:
  • Use either the Unilateral Authentication or Bilateral Authentication radio option for checking the UWB ToF measurement.
  • Each time any of the PEPS command buttons (Start/Stop, Unlock or Lock) are clicked, a new PEPS wake-up signal is generated. Once the fob receives the wake-up signal, the LED on the fob blinks and the PEPS Message Status window information is updated.
  • A continuous polling sequence can be achieved by checking the “Polling” check box in the “PEPS Features” section of the System Configuration window. Use this polling feature to dynamically determine the PEPS and UWB fob area coverage in real-time with the results displaying in the PEPS Message Status window.