Extend the OsmoNITB SMPP implementation with support for USSD.
SMPP is a protocol that can not only carry SMS, but also USSD. However, the current SMPP 3.4 implementation in OsmoNITB doesn't support that yet.
The task would be to study SMPP 3.4 regarding USSD transfer, look at the current USSD code in OsmoNITB and extend it in a way to forward MT-USSD via SMPP
to an ESME.
A suitable test ESME would also have to be written for testing.