Found some SO Q&A about how to send and receive USSD messages (exchanged with the cellular network) on Android. I understand that one needs to register a BroadcastListener to receive USSD message, but have further questions (so far, admittedly theoretical i.e. without having attempted to write code for this).
On Android it is possible (and if so what are the specific things to take care of) so that my application gets to receive the USSD message from cellular network, even though it is not the foreground application, and even though the screen is locked, or when the device is in sleep-mode ?
From what I have read so far, it seem that I'd need a background service that registers the BroadcastListener for USSD message, that can then send a local Notification, to wake up the application which can offer UI for interaction with user. Is that correct ?
Note that the desired behaviour is somewhat analogous to GCM/FCM Notification being used to wake-up an application from sleep (post user interaction responding to the Notification). However, in this case there is no GCM/FCM, but only USSD message from the network.
