Iphone 4 with T-mobile service Research in United States

vip0071 · Jan 4, 2011

If you r using Iphone 4 in T-mobile in USA, could u pls give us your kind feedback here? The newcomers who r considering to jump out ATT highly appreciate your help!!

1. How do you feel about the internet speed under Edge (2G) comparing with 3G of ATT? How about using computer by tethering via Iphone 4 (such as downloading speed)?

2. Any inconvenience you find out using iphone 4 under T-mobile?

3. Do I have to jailbreak if we only switch to T-mobile? I know that Carrier Unlock is not available from ATT or Apple right now. Seems that other ways of unlock is based on the condition of Jailbreak, is that right?

4. A stable software for Jailbreak for IOS 4.2.1 is not available, right? Therefore, how shall I unlock or Jailbreak Iphone 4 updated to IOS 4.2.1?
I found two ways, but don't know whether it would work: (1) some advertisements on ebay or google show they could jailbreak IOS4.2.1. Is that reliable? (2) Some video show that I could downgrade 4.2.1 to previous version, then Jailbreak. I was wondering without any previous back up, can I downgrade it? Or I could download and use some other's back up?

5. In case I successfully downgrade it to the previous version, which software of jailbreak I shall use? Seems that Jailbreakme is very simple to use?

Thank you in advance!!

Dj101 · Jan 5, 2011

i am on att so the first two questions someone else can address

3...you have to jailbreak in order to apply the unlock...and unlocked phones are availible,mainly overseas,but they are availible.they are factory unlocked.

4.its not the firmware that matters in the unlock,its the baseband
so,technicly,you could have a phone with the unlockable 1.59 baseband with a currant firmware,but that is an undertaking to accomplish,and i personally wouldnt want to part with a phone i had put so much time and energy into.and that phone would most likely already be unlocked

so if your looking to buy a used phone and unlock it,make sure it has ios 4.01 with 1.59 baseband....i could be wrong,but i do beleive this is the only firmware and baseband that is easy to jailbreak and unlock
probly hard to find a phone in that state still

Bobik · Jan 5, 2011

well, what he said + you can unlock 4.0, 4.0.1, 4.0.2. I would recommend stick to 4.0.1. T-mobile 2G internet sucks!!!

vip0071 · Jan 7, 2011

Hi, Thank you!

I'm currently at att, thinking of switching to tmobile. I turned off the 3G on my iphone 4 to try 2G, it's not bad to use safari, but it really sucks to watch video. Then, it make no sense to have an unlimited data plan at Tmobile for so slow speed.