What is USSD, do you mean
this? And by Rhino, do you mean the
Rhino JavaScript engine?
Those two are two totally different things and there is no answer to the question "how to use Rhino SDK to develop USSD service".
If you mean something else by "USSD" and "Rhino" then please explain in detail what you mean. Your questions is too vague to give any meaningful answer to it.