The latest source was uploaded to the Google Drive and includes a working RIL that supports PPP and SMS at the same time.
The Huawei Generic RIL was used to replace the Allwinner RIL which would not send or receive SMS.
The new one also supports USSD but needs the phone interface to use this so the build includes this now.
The only outstanding issue is that SMS’s don’t seem to be removed from the SIM so I am still working on code to sort this. You can use the Messaging App to read and delete these from the settings menu. For now I delete any SMS’s stored on boot up as they have already been read. This is done before the system is connected to the network so any new SMS waiting to be delivered are not affected.
I’ll post up the fix once I have it working and fully tested.
Get the code here. Android Source