You can upgrade your baseband, but not downgrade for unlocking solutions until Apple still signs required firmware.
What happens when we have new SHSH servers ?
If you are following the jailbreak and unlock scene you would know this is not entirely new but with these SHSH Servers you can downgrade your "unbelievable" 4.11.08 baseband ?
The BeijingiPhonerepair today reported that he received e-mail from Chinese Hackers in which they wrote that the Hackers group developed SHSH Server that Allows you to downgrade from 4.11.08 to 4.10.01 Baseband ( Described below ) :
Downgrade 4.11.08 Baseband - Translated text:
"Downgrade baseband service is available to those who have mistakenly updated to iOS 5.0 or 5.0.1 and stuck on baseband 4.11.08.
Software downgrade service: Downgrades to firmware 4.3.5, baseband 04.10.01, no SHSH backup required.
Guaranteed non-hardware type of downgrade, disassembling is not required, will not break your device in any way. You can put a tamper proof sticker on the screws (to prove that the iPhone is not taken apart)"In addition, no other description or explanation of how the downgrade "mechanism" works. We think that behind this is probably the Gevey SIM developers team.
We come to think of it, maybe this is really sensible answer because downgrading to 4.10.01 will allow more continued sales of his Gevey SIM which became obsolete after releasing the iOS 5.0 firmware in October 2011.
One of the most popular iDevice Chinese forum is also talking about this downgrade solution.
What you think ? Whoever's behind this ? Stay tuned to unlockboot and expect more about this.