220-1102 Question 325
Single answerMobile digital keyA property management company issues mobile digital keys to staff smartphones so they can unlock office suites without physical badges. One employee reports that their phone shows the key as active in the app, but the door reader does not respond when they hold the phone near it. The same employee can still use Wi-Fi and cellular data, and another employee's phone works at the same door. Which action should the technician check FIRST to most likely restore access?
- A
Verify that NFC is enabled on the employee's smartphone
- B
Factory reset the smartphone and reinstall the digital key app
- C
Disable the phone's screen lock because it can block door-reader communication
- D
Replace the building's Wi-Fi access point nearest the door reader
Show answer and explanation
Correct answer: A
Explanation
The best first step is to verify that NFC is enabled on the employee's phone. In real-world mobile credential environments, digital keys may be provisioned in a vendor app or wallet and then transmitted to the reader using short-range wireless technologies, especially NFC. A phone can still have normal Wi-Fi and cellular service while NFC is off, so general connectivity does not rule out an NFC issue. Standard troubleshooting best practices for A+ Core 2 scenarios favor checking the simplest, least invasive cause first before taking disruptive actions such as resetting the device. Vendor documentation for mobile access systems and smartphone support documentation commonly instruct administrators and users to confirm that the required radio, such as NFC, is enabled and that the device is held close to the reader.
- A. Correct.
Correct. Many mobile digital key deployments use NFC for short-range communication with a compatible door reader. If the digital key appears active in the app but the reader does not react when the phone is held near it, checking whether NFC is enabled is the most appropriate first troubleshooting step. This fits the symptom because the phone's general network connectivity can still work even when NFC is disabled.
- B. Incorrect.
Incorrect. A factory reset is far too disruptive as an initial step and is not justified by the symptoms. Since the app shows the key as active and another user's phone works at the same reader, the issue is more likely related to a local phone setting such as NFC rather than a need to erase the entire device.
- C. Incorrect.
Incorrect. Screen lock is typically a security requirement for devices storing credentials such as mobile digital keys, not something that should be disabled. In many enterprise and wallet-based credential systems, device security features help protect the key. Disabling screen lock would reduce security and is not a standard fix for reader communication problems.
- D. Incorrect.
Incorrect. The fact that another employee can use the same door reader successfully indicates the door system is functioning. In addition, proximity-based mobile digital key systems commonly rely on NFC or Bluetooth Low Energy rather than the nearby Wi-Fi access point for the actual unlock interaction.