iPhone 3GS tether w/o JB

[krishna]

My iPhone 3GS 3.0.1 since last two weeks started having issues with Battery life. It just acts funky. 100% charge left on desk would depletes so quickly in 5-10mins phone is dead. sometimes phone stays charged fine. Other times it reports 100% to 70% to 18% to dead just in 5mins. So i called Apple care and they are sending a phone overnight. I believe phone probably will come with iOS 4.2.1. Now i cannot tether with unless I do JB.

The question: I used benm profile hack to tether the phone with 3.0.1 iOS. Does benm supports higher iOS like 3.1.2? Is 3.0.1 better OS or 3.1 or 3.1.2 (as long as it can tether?)

Thanks

[Shadrack]

I don't think that the profile hack still works on updated iOS versions. You can tether through most providers w/ a service fee (AT&T is $20/mo). That doesn't require JB. If you don't want to pay the fee I believe there is a 4.2.1 JB, and that would be the only way (that I know of) to get tethering w/o paying a monthly fee for it.

[krishna]

I'm thinking to downgrade to iOS 3.x.x to get that tether if higher iOS is not possible. If I downgrade which iOS does benm supports upto? which guide is good to use for downgrading?

[Shadrack]

I'm thinking to downgrade to iOS 3.x.x to get that tether if higher iOS is not possible. If I downgrade which iOS does benm supports upto? which guide is good to use for downgrading?

There is no way of doing any downgrading (that I know of) unless you JB your phone. Apple authenticates iOS installs via their server and require the latest version to be installed.

You would need the SHSH Blob for 3.x.x for your hardware in order to downgrade. Most people make an effort to Jailbreak just to have these SHSH blobs saved for their hardware in case they need to downgrade. I think that if you were to Jailbreak it at 4.2.1 you may be able to obtain those SHSH Blobs using a program like TinyUmbrella or enabling them to be saved to Saurik server via Cydia (then follow directions found here or do some Google searching).

I'm not 100% sure this will work, however. I think if you JB your device the furthest SHSH Blob would be v4.0.x which would be the earliest firmware of iOS you can downgrade to.

Alternatively, you can Jailbreak and install MyWi (free trial, $20) which enables USB, Bluetooth, and WiFi Hotspot tethering. Only other way that I know of is paying your service provider for tethering.

Edit: Looks like TinyUmbrella doesn't require JBing your phone. I would look more into that if I were you.