# T-mo S3 on at&t network with HSPA+



## pokedroid (Jun 24, 2011)

I was considering buying the T-mobile variant, as I do not need or want LTE, but I also don't want to pay what the European sellers I've found are asking for. My question is, will the T-mo version work with at&t's HSPA+? I don't want the battery drain of an LTE radio, but would still like to have "4g" speeds. Also, if anyone wants to inform me why this might be a BAD idea, then please feel free. I've had LTE and don't think I'll miss it if I have +, but if throwing that radio out won't help on battery life, then i guess i might as well go w/ the LTE model.

Thanks!


----------



## pokedroid (Jun 24, 2011)

Nothing









Sent from my Galaxy Nexus using Tapatalk 2


----------



## PhantomGamers (Sep 27, 2011)

Apparently the LTE radio on the S3 doesn't affect battery life at all... or at least the impact is so minimal it's not even noticeable.
The tests were done with AT&T LTE but I would assume it's the same for Verizon and any other carrier that offers an LTE model.


----------



## pokedroid (Jun 24, 2011)

Oh, that's good news! I still haven't been able to find any confirmation on hspa+ compatibility so this holding true would essentially solves all my problems! Then I could buy one on contract and get the subsidy. One more contract won't kill me, I suppose









Sent from my Galaxy Nexus using Tapatalk 2


----------



## snobrdr2324 (Jan 19, 2012)

All sources point to yes it will work with ATT. Its iffy though because tmobiles website doesn't list the 1900 band for HSPA but all other websites and the FCC filings say that the tmobile version does indeed support ATT's frequencies. So take it for what you will, however, the issue I see that is more pressing is unlocking the Tmobile version to work on ATT even if it does for sure have the hardware needed.

*Edit:* I found an AnandTech article which is very reuputable that also claims that the Tmobile version supports ATT's frequencies, so it looks like it will work if you can get it unlocked.
*"Like the HTC One S, the T-Mobile SGS3 can be used on AT&T's 3G network if you can manage to unlock one. This is a definite plus if you don't care about LTE but do care about having a phone with a ton of WCDMA bands supported."*

http://www.anandtech...-usa-variants/8


----------



## pokedroid (Jun 24, 2011)

snobrdr2324 said:


> All sources point to yes it will work with ATT. Its iffy though because tmobiles website doesn't list the 1900 band for HSPA but all other websites and the FCC filings say that the tmobile version does indeed support ATT's frequencies. So take it for what you will, however, the issue I see that is more pressing is unlocking the Tmobile version to work on ATT even if it does for sure have the hardware needed.
> 
> *Edit:* I found an AnandTech article which is very reuputable that also claims that the Tmobile version supports ATT's frequencies, so it looks like it will work if you can get it unlocked.
> *"Like the HTC One S, the T-Mobile SGS3 can be used on AT&T's 3G network if you can manage to unlock one. This is a definite plus if you don't care about LTE but do care about having a phone with a ton of WCDMA bands supported."*
> ...


Thank you for this info! As someone who is new to GSM tech, when the author says "3g network", that includes HSPA+ right? I realize that LET and + are not technically 4G, but they're always advertised as such, so I wanted to ensure that their 3G and beefed-up 3G still mean the same thing.


----------



## snobrdr2324 (Jan 19, 2012)

In short, yes the 3g and '4g'/beefed up 3g are exactly the same technology and run on the same frequencies, just one is simply upgraded with more backhaul to support higher throughput. So the Tmobile GS3 will work as a '4g' phone on ATT in that it can connect to the HSPA+ 21 network that att dubbed 4g.

ATT's 3g and '4g' networks don't operate simultaneously like the 4g LTE and 3g network on Verizon or even att's 4g LTE network. This is because their '4g' is a simply a 3g network that ATT's marketing team rebranded to keep up with Verizon's in the 4G race while the rest of the world still calls the exact same thing 3g. When one of ATT's towers is upgraded to HSPA+21(4g) it replaces the slower HSPA+ 7/14.4 that ATT at one time called 3g. Tmobile did the exact same thing except they use HSPA+42 which is actually more comparable to Verizon's 4g LTE network, but is still simply an evolution of of 3g technology still. And you are right that LTE isn't actually a 4g technology either but it is much closer to LTE-Advanced which is true 4g where HSPA+ is only very loosely related to LTE in that they are both considered GSM, but in practice are very different technologies.

Now all of this is theoretically possible, but I'm not sure I fully understand your plan still. You want to buy a subsidized Tmobile GS3, then pay the ETF and use it with ATT? To answer your question as to why this might be a bad idea, as I said, it is theoretically possible, but all of the big 4 carriers lock their phones to only be used on their network. The GSM carriers and a few phones on Verizon can be unlocked to accept an international sim card by calling customer service. But as far as I know, none of them will ever unlock the phone to be used on other US carriers despite there being no technical limitations to do so. They just don't want you taking the phone to a local competitor. So the only way I see what you want to do being possible is to root the phone and hope that someone comes up with a 3rd party developer Sim unlock mod, which is iffy at best and might never happen. My opinion would either buy the very nice international version with its better GPU and better developer support and just pay the couple hundred extra. Or just buy the ATT version turn off the LTE radio which wouldnt have any adverse affects on battery or very minor at worse, but saves the huge hassle of trying to get a Tmobile phone to work on ATT.

If you have any other questions about what you want to do or about GSM/CDMA technology as a whole I'll be happy to try and answer.


----------



## imneveral0ne (Jun 18, 2011)

snobrdr2324 said:


> In short, yes the 3g and '4g'/beefed up 3g are exactly the same technology and run on the same frequencies, just one is simply upgraded with more backhaul to support higher throughput. So the Tmobile GS3 will work as a '4g' phone on ATT in that it can connect to the HSPA+ 21 network that att dubbed 4g.
> 
> ATT's 3g and '4g' networks don't operate simultaneously like the 4g LTE and 3g network on Verizon or even att's 4g LTE network. This is because their '4g' is a simply a 3g network that ATT's marketing team rebranded to keep up with Verizon's in the 4G race while the rest of the world still calls the exact same thing 3g. When one of ATT's towers is upgraded to HSPA+21(4g) it replaces the slower HSPA+ 7/14.4 that ATT at one time called 3g. Tmobile did the exact same thing except they use HSPA+42 which is actually more comparable to Verizon's 4g LTE network, but is still simply an evolution of of 3g technology still. And you are right that LTE isn't actually a 4g technology either but it is much closer to LTE-Advanced which is true 4g where HSPA+ is only very loosely related to LTE in that they are both considered GSM, but in practice are very different technologies.
> 
> ...


what he said ^^


----------



## pokedroid (Jun 24, 2011)

snobrdr2324 said:


> In short, yes the 3g and '4g'/beefed up 3g are exactly the same technology and run on the same frequencies, just one is simply upgraded with more backhaul to support higher throughput. So the Tmobile GS3 will work as a '4g' phone on ATT in that it can connect to the HSPA+ 21 network that att dubbed 4g.
> 
> ATT's 3g and '4g' networks don't operate simultaneously like the 4g LTE and 3g network on Verizon or even att's 4g LTE network. This is because their '4g' is a simply a 3g network that ATT's marketing team rebranded to keep up with Verizon's in the 4G race while the rest of the world still calls the exact same thing 3g. When one of ATT's towers is upgraded to HSPA+21(4g) it replaces the slower HSPA+ 7/14.4 that ATT at one time called 3g. Tmobile did the exact same thing except they use HSPA+42 which is actually more comparable to Verizon's 4g LTE network, but is still simply an evolution of of 3g technology still. And you are right that LTE isn't actually a 4g technology either but it is much closer to LTE-Advanced which is true 4g where HSPA+ is only very loosely related to LTE in that they are both considered GSM, but in practice are very different technologies.
> 
> ...


What an amazing response. Thank you so so much! So something that I thought would be super easy based on the popularity of the device (a sim unlock) is "iffy at best". My plan wasn't to buy one on subsidy, as i think at the end of the day it would be more expensive. Honestly, i do know of an authorized retailer store where I used to live that will unlock phones for a phone but I don't know what his ability to unlock a sgs3 would be. I guess I could call sometime and see...

Anyway, now my question becomes battery/heat efficiency. From what I've read the battery life is similar on both varieties, but i know that the S4 chipset with the integrated LTE runs very efficiently. I'm currently using a VZW galaxy nexus and having my phone hover around 90 degrees a LTE on and reaching over 125° when using GPS sucks.

At the end of the day, I think I'm just gonna go with the at&t version. Seems like the extra money I'd spend wouldn't net me enough value to be worth it. Most discussion I've read so far says the 2gb of RAM is more valuable that the quad-core processor.

Thanks for everyone's help and feel free to keep the discussion going if you like.

Sent from my Galaxy Nexus using Tapatalk 2


----------



## snobrdr2324 (Jan 19, 2012)

pokedroid said:


> What an amazing response. Thank you so so much! So something that I thought would be super easy based on the popularity of the device (a sim unlock) is "iffy at best". My plan wasn't to buy one on subsidy, as i think at the end of the day it would be more expensive. Honestly, i do know of an authorized retailer store where I used to live that will unlock phones for a phone but I don't know what his ability to unlock a sgs3 would be. I guess I could call sometime and see...
> 
> Anyway, now my question becomes battery/heat efficiency. From what I've read the battery life is similar on both varieties, but i know that the S4 chipset with the integrated LTE runs very efficiently. I'm currently using a VZW galaxy nexus and having my phone hover around 90 degrees a LTE on and reaching over 125° when using GPS sucks.
> 
> ...


Glad I could help . Now I might be wrong about the sim unlock being iffy, this will be a very very popular phone and I'm sure there will be some work done to unlock the sim for other US carriers, this was just my guess based on a tiny bit of experience. If/when it does come it typically isn't a simple process and limits your options when updates roll out for fear of removing the sim unlock in the update. I couldn't speak for the ability of the authorized retailer to unlock it, but I guess in theory it is possible as well, again it seems like more hassle than it is worth imho.

I also have the Verizon Gnex and understand your fear of heat as this thing gets hot just looking at it even when underclocked, which is incredibly annoying. I can't speak for the heat generation of the s4 obviously because I don't have one lol, but this article might help a little and all reports point toward this being one of the coolest chipsets to date from many other sources. It is a 28nm manufacturing process as well which is the smallest and most heat efficient yet.

http://www.extremetech.com/computing/131263-is-qualcomms-snapdragon-s4-the-coolest-soc-on-the-block-you-butter-believe-it

The battery life, especially with the more efficent GSM radios running even on LTE should be much much better than the awful battery life this CDMA Gnex gets. The anandtech article I linked earlier gives you the battery life reports from the ATT and Tmobile versions alike on HSPA+, but the reviewer says he has to drive to an ATT LTE area to test LTE battery life which he will do when he gets a chance. Even without LTE, the ATT model scored almost identical and in a few tests a good margin better than the Tmobile version surprisingly, so it appears that there is no advantage to getting the Tmobile version from a battery standpoint.

So all this considered I would definitely support just getting the ATT version. It's cheaper even at full price than the Tmobile version, it gets equal and possibly better battery life, it wont require any difficult unlocking/modifications and it will get updates as quickly as all the other ATT phones do(which is still quite slow). Who knows, maybe one day you might even want to use LTE and this gives you that option in the future, especially given that the HTC One X which uses the same chipset gets very good battery life on ATT LTE.


----------



## pokedroid (Jun 24, 2011)

This is very true, and regardless of my reservation everything has echoed what you said so far, that the LTE won't affect the battery life. Plus with the money I'm saving I can afford the 16gb model and still throw my class 10 32 in it and never run out of space and FINALLY get some premium accessories to compliment it.

Sent from my Galaxy Nexus using Tapatalk 2


----------

