Need Help Unlocking iphone baseband 05.16.02 firmware 4.3.5

[needhelp#IM]

i have the iphone with a baseband of 05.16.02 and firmware of 4.3.5. i am aware that ultrsn0w doesnt have an unlock for these versions. what would be the best way to unlock the phone? upgrade to baseband 06.15.00?

please help and thank you

 

[Peligro911]

What iPhone 3GS ?

 

[needhelp#IM]

iphone 3gs yes.

 

[Peligro911]

I would say yes but 4.3.5 does not have a unteathered JB