Q1. Consider the following statements about Kavach data, authentication and failure handling: 1. Stationary and onboard Kavach units verify the CBC-MAC code for every message before processing. 2. In case both GPS/GNSS and the real-time clock fail, the Onboard Kavach unit stops radio communication and switches to System Failure mode. 3. The onboard vital computer has real-time clock synchronization facility with GNSS clock. 4. If both GPS/GNSS and real-time clock fail, the Onboard Kavach unit continues normal radio communication without reporting to the Network Monitoring System. Which of the statements given above are correct?
Explanation
Statements 1, 2 and 3 are correct. Statement 4 is false: the specification requires stopping radio communication, switching to System Failure mode and sending a message to NMS through GSM/LTE.