Smartphone That Works With T-Mobile and AT&T

[SpicyCurry]

Does anyone have a suggestion for a high end smartphone that works with both T-mobile and AT&T? I currently have an unlocked 2G iPhone, and am looking for an upgrade. Been trying to search whether the Samsung Vibrant can work with both carriers, but I didn't find a clear answer. And when I say works with both carriers, I mean you can hot-swap the SIM cards into the phone and either will work.

I am also not in a rush to upgrade so if you have suggestions on upcoming phones, that would also be appreciated. I've read about two phones T-mobile expected in Q4, the HTC Vanguard and HTC Emerald. Again though, I don't know if these are compatible with AT&T.

 

[abaez]

Any GSM phone would work on either carrier.

3G won't work on either carrier until a 4 band 3G phone is released that works with both carrier's frequencies, which hasn't happened yet.

 

[AMDZen]

Any GSM phone would work on either carrier.

Any unlocked phone. If its a T-mo phone, T-mo will unlock it for you if you've been a customer for any length of time

Any iPhone can be unlocked as of now except the 4 and that is only a matter of time. Maybe the 3GS if you like your 2G. Otherwise, I suggest whatever T-mo has and getting it unlocked after you buy it - or look online but make sure its an "unlocked" version which costs a lot more.

 

[Nebor]

Any GSM phone would work on either carrier.

3G won't work on either carrier until a 4 band 3G phone is released that works with both carrier's frequencies, which hasn't happened yet.

What he said. I believe we should see a 4 band 3g phone from Nokia by the end of this year.

 

[BigSmooth]

The upcoming Nokia N8 will supposedly have both ATT and T-Mo 3G U.S. bands, but who knows about pricing or availability at this point. If you don't want to wait or get onto a contract, I'd suggest a Nexus One in whatever 3G flavor you'd use more often and then just deal with EDGE on the other carrier.

 

[pm]

As has been said, excepting for 3G access, any AT&T cell phone, and most tri-band and all quad-band international GSM cell phones will work on T-Mobile in the US. The trick is that to take the T-Mobile SIM, they need to be unlocked, also called "simfree". For 3G access, as Nebor said, at least one Nokia phone is rumored to use both AT&T's and T-Mobile's 3G frequencies, but all the rest are stuck on either AT&T's 3G network, or T-Mobile's 3G network, and a most European 3G phones won't work on either in 3G mode.

As far AMDZen's suggestion of an iPhone 3GS as a replacement, I would caution that unlocking an iPhone 3GS is decidely trickier than a 2G or the 3G. With the 2G iPhone, you could just BootNeuter it and do whatever you wanted. With the 3GS, they implemented some form of encrypted handshaking thing which the hackers call "SHSH blobs" and it's definitely funkier than it was on a 2G. I speak from experience. It's not rocket science, but it's definitely not as easy as it is with a 2G (or 3G) iPhone. Unless a miracle occurs (and that's not likely now that GeoHot has thrown in the towel), the iPhone 4 unlock will have this issue too. So... either accept that it's a bit more painful to hack, or be very careful to buy a "factory unlocked" iPhone 3GS on Ebay.


If it was me, I would first decide what OS I want - iPhone, Blackberry, or Android. And then figure out what I want to spend and then figure out what devices fit in that list that are unlocked. One suggestion that I never see anyone mention is an Acer Liquid (Android, 1Gz Snapdragon, 800x480 pixel screen, quad-band) which can be found for around ~USD325 unlocked if you look around.

 

[s44]

I see the Liquid has gotten some OS updates, but its smallish screen still makes it less tempting than if we could get the Captivate at the announced price.

 

[pm]

I see the Liquid has gotten some OS updates, but its smallish screen still makes it less tempting than if we could get the Captivate at the announced price.

I wouldn't call the screen "smallish". It's 3.5" - which is smaller than the newer 4" screens, but it's the same as the iPhone and most other smartphones except the most recent crop. But aside from that, I agree. If it was available for $350, the clear choice would be the Captivate. At $450, the choice becomes harder. If you can score an unlocked Liquid for $300-350, and a 4" screen isn't a necessity then I'm not sure the 50% higher price tag for the Captivate is a great deal. Although I don't know that I'd call the pre-release rumor an announcement despite the official channels it seemed to come from.

 

[AMDZen]

As far AMDZen's suggestion of an iPhone 3GS as a replacement, I would caution that unlocking an iPhone 3GS is decidely trickier than a 2G or the 3G. With the 2G iPhone, you could just BootNeuter it and do whatever you wanted. With the 3GS, they implemented some form of encrypted handshaking thing which the hackers call "SHSH blobs" and it's definitely funkier than it was on a 2G. I speak from experience. It's not rocket science, but it's definitely not as easy as it is with a 2G (or 3G) iPhone. Unless a miracle occurs (and that's not likely now that GeoHot has thrown in the towel), the iPhone 4 unlock will have this issue too. So... either accept that it's a bit more painful to hack, or be very careful to buy a "factory unlocked" iPhone 3GS on Ebay.

Some of what you are saying is true, but the reality is that SHSH blobs only come into affect if you accidentally update and need to go back to an older firmware. Otherwise, Jailbreaking any 3GS right now is as simple as its ever been (a few clicks), and unlocking it is as simple as downloading ultasn0w from Cydia. The exception is if you update to 4.0 on the 3GS with the newest bootloader. Cydia will automatically backup your SHSH blobs also so you are good on that front.

See Howard forums for details, this is a good matrix to keep up with firmware.

http://www.howardforums.com/showthr...atrix-(Jailbreak-or-unlock-anything-after-2.x)

 

[pm]

As the owner of a iPhone 3GS which was upgraded to 4.0 accidently when my wife plugged it into her laptop and clicked a couple of dialog boxes and Cydia somehow didn't back my SHSH blobs up... I disagree.

I'm travelling in the UK now and when my iPhone 3GS relocked itself, life became a bit more annoying. I had never heard of SHSH blobs until I discovered that somehow I don't have mine.

Right now my 3GS is stuck on 4.0 and there's no unlock or jailbreak in sight. They've been saying it's coming for weeks...

Like I said, it's not rocket science (so I agree with the spirit of what you wrote)... but back with my iPhone 2G if it relocked itself, I knew how to undo it... I wasn't stuck with an AT&T locked brick for the better part of a month.

But since I'm living the annoyance of my iPhone 3GS not working and I'm reading in a thread that you are recommending it as an upgrade option, I thought that I'd add my caution.

 

[SpicyCurry]

If it was me, I would first decide what OS I want - iPhone, Blackberry, or Android. And then figure out what I want to spend and then figure out what devices fit in that list that are unlocked. One suggestion that I never see anyone mention is an Acer Liquid (Android, 1Gz Snapdragon, 800x480 pixel screen, quad-band) which can be found for around ~USD325 unlocked if you look around.

I'm leaning more towards an Android phone. One of the main things I'm looking for is a fast, snappy phone. I've played with a couple 1GHz Snapdragon phones running 2.1 Eclair. It's pretty fast (faster than my current 2G iPhone obviously), but not as fast as I was hoping for. Hopefully the 2.2 Froyo update will give the performance boost that I'm looking for.

With that said, does anyone have a Android phone running 2.2 Froyo with a 1GHz CPU? What's your personal experience with them?

Also, a lot of people mentioned that the 3G on current phones is not compatible with both AT&T and T-Mobile. If I were to buy T-Mobile phone now and use it's 3G network, can I potentially switch carriers next year and use AT&T 3G with the exact same phone? Is it possible through changing APN settings, etc.?

Thanks for all the advice.

 

[pm]

Also, a lot of people mentioned that the 3G on current phones is not compatible with both AT&T and T-Mobile. If I were to buy T-Mobile phone now and use it's 3G network, can I potentially switch carriers next year and use AT&T 3G with the exact same phone? Is it possible through changing APN settings, etc.?

In a word, no.

It's a matter of frequencies and the antenna and the chips inside the phone.

T-Mobile USA is using 1700MHz (Uplink) and 2100MHz (Downlink) for it's 3G network.
AT&T is using 850MHz (U/D) and 1900MHz(U/D) for it's 3G network.

There are no shipping phones that cover both sets of frequencies. So you can get a 3G phone that works on AT&T or you can get one that works on T-Mobile, but you can't have both. If you are content to run it on EDGE, then you can take a 3G phone from one network and run it on the other on EDGE.

As far as 1GHz, well, just quoting the processor isn't the whole story - even though I do it all the time. The new Samsung Galaxy line have dedicated video processors and they do a very nice job speed up the feel of the phone - I tried one the other day in a Carphonewarehouse here in the UK (Samsung Galaxy i9000 - the equivalent of the Captivate and Vibrant) and it was really slick. I would recommend trying either the T-Mobile Vibrant or the AT&T Captivate (same phone more or less) and seeing what you think of that.