What are the AT commands to send a flash SMS?
I’m not sure if it’s possible for a general device to do this - it might be something that only the network can do (or is allowed to do)?
See: dreamfabric.com/sms/ (which suggests that it’s also phone-specific)
If it’s possible (or permitted), You’ll probably have to do it in PDU mode so that you can set the necessary flags?
Or perhaps go via an SMS service provider…?
I have an HSDPA Modem (Option GlobeSurfer), it has the ability to send a flash SMS. And I recall an old SONY mobile phone (Z70), it had the a ability to send a flash SMS too. There must be a code/command from the devices for the flash SMS.
It is described in the Link I gave earlier.