Cellular.RSSI() returns an instance of
CellularSignal class that allows you to determine signal strength (RSSI) and signal quality of the currently connected Cellular network.
This function queries the cellular modem for the RSSI. This is normally quick, and does not use cellular data.
However, it is possible that the call will still block for an indeterminate amount of time, possibly for as long as 10 minutes. This can occur if the system thread is busy trying to reconnect to cellular and is unable to do so. Doing operations that access the cellular modem or require access to the system thread from a separate worker thread is a good workaround.