How programmaticaly replace internal mechanism for SMS sending

I want to use SMPP for sms sending rather then standard mechanism. Can I programmatically replace mech开发者_高级运维anism of SMS sending to my own?

You can create your own Android firmware and attempt to replace the SMS subsystem with one of your choosing.

You can write your own SMPP client and distribute it through the Market, presumably (I do not know much about SMPP).

You cannot modify the SMS subsystem on an existing phone via an app distributed through the Market, though.