Joined: 22/03/2008 00:37:15
Location: Cambridge, UK
In a first instance I'd suggest contacting the operator or the SMSC/USSD GW vendors. The SMPP specification allows sending/receiving USSD messages over SMPP. Therefore, if the SMSC vendor supports it, you may not need any USSD specific product.
However, note that OpenCloud's application server (Rhino) supports apps with the MAP protocol (ie, for USSD messages directly to the HLR) and the SMPP protocol. Rhino has been considered on implementations of USSD gateways and SMPP related solutions.