USA Sim Card from T-Mobile

[bamnutsak]

^ You can also buy bundles (SIM + plus $60 credit) on eBay, sometimes at significant discounts.

Make sure you get the proper size SIM for your phone. I ordered a batch ($4.14 each/eBay) of micro-SIMs for Thai people traveling to the U.S. I pre-activated two while in the U.S. so they'd have numbers and service when they arrive.

You can port in an existing number (fixed-line, mobile, even VoIP) to T-Mo, or you can choose your own number.

Activating the T-Mo SIM is very easy, you can choose a number in a certain area code, although the number pool is limited.

Managing your account via the web interface is very easy.

They also have a $10/7 day unlimited talk/text option.

A T-Mo SIM does roam here in Thailand; good for OTP SMSes - I'm not certain a t-Mo MVNOs SIm (like Simple, StraightTalk, etc.) would roam here?

[TallGuyJohninBKK]

If this is the OP's phone, it shows the frequencies available... no problem for voice and text via 2G in the U.S., but getting 3G data he'll need to match up with the right carrier offering those bands.

900/2100 only for 3G is OK for Thailand given all the majors run on 2100 Mhz, but it's pretty limiting in terms of U.S. 3G carriers. For example, it looks like AT&T is running 850 and 1900 Mhz for their 3G.

Edited August 30, 2015 by TallGuyJohninBKK

[rapom]

Sorry I mean one of the sim cards I buy in the states. Thanks

I think the OP's question has been answered. Numerous posters have strayed from the question asked. He is not asking about what T-Mobile sim to buy. He wanted to know if the phone he purchased in Thailand can be used in the US, when he gets back home. It has been answered that it will work, if it is unlocked , it can be used on att, t-mobile or gsm networks in the US. That is the answer.

[gk10002000]

Yes.

T-Mobile/U.S.A. has a roaming agreement here with AIS.

My pre-paid T-Mo/US SIM does work fine here, but I haven't used it since the bombing. Not sure how the authorities plan to deal with foreign SIMs roaming here in Thailand. Obviously tens of thousands of diplomats, VIPs, business people need to come to Thailand and have their phones roam. But then I can see the Junta cracking down on this.

what about one million or so tourists that have phones from their home countris? Many of them I would think would work in Thailand. I am told my ATT phone will work on the Thai networks, compatible frequency and mode wise and according to ATT folks. Unless Thailand is not letting any phones from outside the country work for any travelers?

[TallGuyJohninBKK]

what about one million or so tourists that have phones from their home countris? Many of them I would think would work in Thailand. I am told my ATT phone will work on the Thai networks, compatible frequency and mode wise and according to ATT folks. Unless Thailand is not letting any phones from outside the country work for any travelers?

In recent years, I've typically bought AT&T origin phones from the U.S., and they've usually come with tri-band 850 / 1900/ 2100 Mhz 3G radios, which means they work fine on the 850 / 2100 Mhz 3G bands that are the main ones in use in Thailand by AIS, DTAC and True.

However, as things transition to LTE, that seems like it's going to become more of an incompatibility, unless you are using a relatively expensive phone that has LOTS of different LTE bands, enough to cover both the U.S. and Thai primary LTE bands.

Right now, it seems, the main U.S. carrier LTE bands are not the same ones as Thailand is using and heading toward using, which seems to be LTE Bands 1 (2100 Mhz) and Band 3 (1800 Mhz). And the more mid-range priced phones in the U.S. often just have the LTE bands to match their originating carrier, but not all the other various ones used elsewhere.

[TallGuyJohninBKK]

He wanted to know if the phone he purchased in Thailand can be used in the US, when he gets back home. It has been answered that it will work, if it is unlocked , it can be used on att, t-mobile or gsm networks in the US. That is the answer.

I'm not sure your statement above is entirely correct, if the OP is using the Galaxy J1 with the specs I posted above.

Yes, based on those specs, he should be able to make calls and send texts via GSM/2G pretty much anywhere or with any carrier in the U.S.

But since the phone seems to be limited to only the 900/2100 Mhz 3G bands for data, those aren't going to match up with all or many U.S. carriers for 3G data, though he may be able to find some carrier supporting those 3G bands. As I noted above, it looks to me like AT&T is using the 850 and 1900 Mhz bands for its 3G service, which his 900/2100 Mhz 3G phone doesn't support. And of course, the J1 has no LTE service at all.

The U.S. carriers have been in transition lately with the movement from 3G to LTE, so the best thing to do is check directly with whatever carrier he's thinking to use and ask if their network will support 3G on the 900/2100 Mhz bands.

Edited August 30, 2015 by TallGuyJohninBKK

[balo]

But he can use T-mobile for data or anything else as we already have mentioned several times. Forget AT&T

[glassdude007]

Be sure too check the Rates for text voice and data use while roaming ......roaming is a total ripoff..

Each country is diferant all ALL charge way too much for use while roaming.

Top up your phone from home before you leave

as it is very hard too top up again unless you have something set up in advance

Better yet just get a cheap phone and set it up in what ever country your in and then use there local cheap international calling plans very cheap too call usa from Thailand with one of these plans.

When I go back too USA I go too 7/11 buy a 20dollar "crack phone" top it up and have cheap international calling no roaming cgarges

[TallGuyJohninBKK]

But he can use T-mobile for data or anything else as we already have mentioned several times.

For voice and texting and very slow 2G Edge data, yes. But for 3/4G data with the OP's Samsung J1 phone, apparently not.

Unfortunately, a lot of folks in this thread were giving out incorrect advice, not even knowing what phone model the OP had until he finally posted it later in the thread. And it's a 900/2100 Mhz 3G only model.

If you look at the T-Mobile website for network coverage, it seems to show their 3G and 4G coverage runs only on Band 4 (1700/2100) and Band 3 (1900 Mhz), neither of which are supported by his phone.

https://support.t-mobile.com/docs/DOC-4988

Balo, your Samsung Galaxy S3 supports 3G data on the 1900 Mhz band, which means it works fine with T-Mobile. But the OP's phone doesn't support that band.

Edited August 31, 2015 by TallGuyJohninBKK

[TallGuyJohninBKK]

BTW, here's a good example of what I was mentioning above about what seems like will be the increasing incompatibility between Asia vs U.S. market devices when it comes to LTE data service compatibility.

Turns out, Samsung also has a 4G/LTE variant of the Samsung Galaxy J1, which is primarily a non U.S. market phone. And it supports a bunch of 4G/LTE bands (in addition to 850/900/2100 3G).... Unfortunately, NONE of the bands currently offered by T-Mobile for their LTE service.

_______________________________________________________________

So, even if the OP had this model phone, it wouldn't match with T-Mobile for any of their 3G, 4G or LTE bands.

Edited August 31, 2015 by TallGuyJohninBKK

[keemapoot]

To be very precise, you have to check two things:

1. The actual GSM network specs on your phone (easy to google the phone model and siamphone for this). Somewhat older phones may not be 4G capable and you are better off with a more extensive 3G network while in the States.

2. Check the network maps by each carrier at the bottom of this page, which shows you exactly the coverage in both 3G and 4G by each carrier by each metro area or rural area. It depends on where you are traveling. Check which frequencies they use in that area.

http://www.phonearena.com/news/4G-LTE--3G-cellular-data-speed-comparison-AT-T-vs-Verizon-Wireless-vs-Sprint-vs-T-Mobile_id64056

Edited August 31, 2015 by keemapoot

[TallGuyJohninBKK]

2. Check the network maps by each carrier at the bottom of this page, which shows you exactly the coverage in both 3G and 4G by each carrier by each metro area or rural area. It depends on where you are traveling. Check which frequencies they use in that area.

http://www.phonearena.com/news/4G-LTE--3G-cellular-data-speed-comparison-AT-T-vs-Verizon-Wireless-vs-Sprint-vs-T-Mobile_id64056

Yes, the T-Mobile map shows you, for any given location, what kind of coverage they have available there... 2G, 3G, LTE, etc. But it doesn't show you what frequency bands they're providing that service on.

So, in the end, someone's still going to have to compare the available frequencies on their phone with the frequencies that their desired carrier is running on. And the maps don't tell you any of that.

[balo]

Ok I think OP mentioned early in this thread he also owned an S3 but check the network settings of your phone before you decide to use it in the US. I have upgraded to Galaxy S5 bought in Bangkok and it worked perfect in Vegas with T-mobile a few months ago.

Edited September 1, 2015 by balo

[TallGuyJohninBKK]

Generally speaking, it tends to be the more expensive phones that are equipped with radios that cover a wider range of 3G and LTE frequency bands.

On the other hand, it's the more economy oriented phones, like the one the OP has, that tend to be more narrow and support only a few bands.

[bamnutsak]

Ok I think OP mentioned early in this thread he also owned an S3 but check the network settings of your phone before you decide to use it in the US. I have upgraded to Galaxy S5 bought in Bangkok and it worked perfect in Vegas with T-mobile a few months ago.

Yes, the OP's SGS3 would be a much better option (than his J1), already covered that in previous posts, as it supports 3G 850/1900. But he did mention he had some sort of problems with that handset?

The SGS5 (SM-G900F is the variant sold here in Thailand) also supports 3G 850/1900 so should work fine on T-Mo's 3G network. It will NOT work on T-Mo's 4G network as it does not support AWS (1700x2100); you'd need the SM-G900T variant.

This SGS5 variant may work on some of AT&T's LTE frequencies (like bands 2 & 5) but these are not available everywhere, and may not be available to PAYG/MVNO customers/

I hacked my Nexus 4, the underlying HW supports AWS, to work on T-Mo's 4G network; it works fine. My Nexus 5 (D821) and SGS5 (SM-G900F) work fine on T-Mo (3G/1900 mostly).

Most "World" phones sold by carriers in the U.S. can/may accept third-party SIMs, and/or can roam on Thai networks.