Closed James-Livesey closed 1 year ago
Test result:
According to the ModemManager logs, this is likely because the modem had become powered off at 14:12, which affects the modem's ability to receive cell broadcasts, but is not the result of receiving the cell broadcast. Hopefully we can re-test this on other planned test dates for minor tests in the future.
Further inspection shows that the CB might have been received, but ModemManager restarted and debug logging was therefore turned off before the CB was received.
With the UK Government planning to test the Emergency Alerts service at 3 PM on 23 April 2023, it will be a great opportunity for us to see if we can receive the planned cell broadcast. Here are the planned contents of it:
We can ensure that we receive all cell broadcasts by running the following command to accept all CB Message Identifiers:
To ensure a stable cell connection, we can run:
Ensure that a USSD response is received after running this (for example, for giffgaff, we can use
*100#
to reliably get the PAYG credit balance information). A response indicates that there is a working connection.To check the logs for the cell broadcast and other information (such as USSD responses and incoming SMS messages), run:
Interestingly, while the phone is asleep and it receives an SMS message, the modem will wake the main phone up using a GPIO wake line. We can observe when this is activated as the screen no longer sleeps and turns on. This indicates that the modem is always active during sleep, and so the cell broadcast should still be received.