Is Straight Talk the only AT&T MVNO?

[fuzzybabybunny]

Geez! You really are confused.

First, separate the frequency (800 MHz, 1700 MHz, etc.) from the communication protocol (HSDPA, LTE, etc.) in your mind. Any protocol can technically use any frequency.

Second, don't get hung up on the number of G's. It's just a term the carriers use to mark the next generation of speed improvements. AT&T and T-Mobile both used to call their HSDPA networks "3G," but they've made some speed enhancements in the past 2-3 years, so they decided to call those same networks "4G." Older "3G" HSDPA phones also connect to the "4G" HSDPA network.

Third, AT&T's LTE is not Verizon's LTE. While they are the same protocol, an AT&T phone will not pick up Verizon's LTE signal (nor will a Verizon phone pick up AT&T's LTE signal). That's all you really need to know about LTE at this point. Since no prepaid account is allowed to access LTE on any carrier, you can put that info on the back burner. Bottom line: you don't need LTE this go round.

Finally, T-Mobile gets "4G" speed of up to 42 Mbps from HSDPA in part because they actually use 1700 and 2100 MHz simultaneously. They use one frequency for the uplink, and the other for the downlink. (I forget which is which, but this effectively lets them dedicate more radio bandwidth to each task, which makes "room" to move more data at a time.) This simultaneous frequency usage is why most unlocked or unbranded phones don't connect on T-Mobile's 3G/4G HSDPA network. If you wish to use T-Mobile, this needs to be considered. Something like the Nexus is just the ticket for a true multi-carrier world phone.


Hope this helps.

Ok, so, to summarize, I should just simplify it.

1. The T-Mobile phone will support DC-HSPA+ for 42Mbit/s. BTW, today I did another speed test on the Nexus using the DC-HSPA+ and I only did 5Mbit/s.

2. The AT&T phone will support HSPA+ (I can get HSPA+ on T-Mobile if I use this phone) for 21Mbit/s. It cannot do DC-HSPA+.

3. I'm still leaning towards the AT&T version because I might want to go postpaid AT&T in the future and get LTE, but for now I'm going to use the $30/month T-Mobile plan. Considering that with DC-HSPA+ on the Nexus I'm only getting 5Mbit/s, using the AT&T phone and getting only HSPA+ shouldn't result in any differences, right? An AT&T GS3 on the T-Mobile prepaid network would still get 5Mbit/s, the same as a T-Mobile GS3 and Nexus, but offer the possibility of doing LTE in the future if I want to go postpaid.

 

[ImDonly1]

No. The AT&T version of the galaxy s3 won't work on tmobile. Forget about the AT&T model on tmobile. It won't get 3G or 4g on tmobile at all. You will only get 2g dialup speeds.

But the reverse is true. The tmobile phone will work on att and their HSPA network, but it doesn't have lte.

 

[Thegonagle]

The T-Mobile phone will support DC-HSPA+ for 42Mbit/s. BTW, today I did another speed test on the Nexus using the DC-HSPA+ and I only did 5Mbit/s.

Yeah, that'll happen due to cell congestion, not enough channels on the air, a slow link to the cell site, or QoS throttling. I doubt anyone's actually seen close to 42 Mbps on a live NON-LTE network. It's pretty rare even on LTE.

You should probably get the T-Mobile version... I think... I'm almost sure... (And if it doesn't work overseas where you go for lack of 900 MHz, buy a cheap little flip phone for calls, and find wi-fi when you need internet. Research which countries use 900 MHz and see if that matters where you go. Or get a Nexus.)