AT&T / T-Mobile 3G frequency bands

**bmold86** · 04-15-2012, 08:24 PM

Hi all,

Living in China and returning in two months, planning on buying some unlocked smartphones here for a good price before returning to the States. Just wondering about the difference between AT&T and Tmobile's 3G frequencies. If I'm not mistaken, AT&T uses 850/1900 and Tmobile uses 1700/2100...

It seems that a bunch of phones over here support just 850/900/2100 for 3G which would mean the 1900 3G band for AT&T would be missing, with the 850 still intact. Does this mean that if I bought a 850/900/2100 phone here and used it on AT&T it would still work whenever there was an 850 band to be had, and not work if 1900 was needed? Same for Tmobile, the 1700 band is missing. What kind of coverage exists between the two 3G bands for both companies? Is this idea just asking for trouble or is it a risk worth taking? Are there any maps that detail differences in coverage between the two 3G bands?

Thanks in advance for any advice!

**Guest 214** · 04-15-2012, 09:44 PM

T-Mobile uses a specific kind of frequency calls AWS and it's the 1700mhz band, if the phone just has 2100mhz it will not receive any kind of 3G signal whatsoever.

Also with AT&T there are some market's with only PCS 3G, and in many area's the 850mhz band is congested to they have surplus capacity on the 1900mhz band, so you may experience poor service quality if you are using a phone with only 850mhz 3G on AT&T, you may see dropped call's and no to slow internet or getting kicked back to GSM regularly.

Ideally for AT&T you need a phone with 1900/850mhz GSM and UMTS/HSPA 3G and for T-Mobile 1900/850mhz GSM and the 1700mhz band for 3G.

**GSMinCT** · 04-16-2012, 09:19 AM

If you're on AT&T you pretty much NEED 850/1900 UMTS/GSM. Otherwise, don't bother. T-Mobile will be rolling out 1900 over their network soon for the iPhone, but it's not done yet, and no official guarantee when/if it will even be completed.

**BuffaloTF** · 04-16-2012, 10:58 AM

Originally Posted by bmold86

Hi all,

Living in China and returning in two months, planning on buying some unlocked smartphones here for a good price before returning to the States. Just wondering about the difference between AT&T and Tmobile's 3G frequencies. If I'm not mistaken, AT&T uses 850/1900 and Tmobile uses 1700/2100...

It seems that a bunch of phones over here support just 850/900/2100 for 3G which would mean the 1900 3G band for AT&T would be missing, with the 850 still intact. Does this mean that if I bought a 850/900/2100 phone here and used it on AT&T it would still work whenever there was an 850 band to be had, and not work if 1900 was needed? Same for Tmobile, the 1700 band is missing. What kind of coverage exists between the two 3G bands for both companies? Is this idea just asking for trouble or is it a risk worth taking? Are there any maps that detail differences in coverage between the two 3G bands?

Thanks in advance for any advice!

Do you see any phones marked penta-band? Galaxy Nexus comes to mind (but not a sales pitch)... That would basically cover you worldwide.... and for sure in the US. T-Mo is also migrating 3G to PCS 1900 currently and now has a roaming agreement with AT&T for 3G on that band as a result of the failed merger... they're planning to ultimately use AWS for LTE. So there may be much more coverage overlap than before.

**Morphling27** · 04-20-2012, 12:48 PM

Originally Posted by BuffaloTF

Do you see any phones marked penta-band? Galaxy Nexus comes to mind (but not a sales pitch)... That would basically cover you worldwide.... and for sure in the US. T-Mo is also migrating 3G to PCS 1900 currently and now has a roaming agreement with AT&T for 3G on that band as a result of the failed merger... they're planning to ultimately use AWS for LTE. So there may be much more coverage overlap than before.

Many Nokia phones come in pentaband flavors.

**mrcamp** · 04-20-2012, 05:15 PM

There are some pentaband Nokia smartphones out there, however not sure about many.

*Sent from my HTC inspire using HowardForums*

**iali76** · 11-16-2012, 01:44 PM

Can someone update this thread as I would like to know if t-mobile finally switched their 3g/4g frequencies to use any compatible ATT device? if,so, can I use my unlocked i747 with tmo 4g prepaid plan?

**i0wnj00** · 11-16-2012, 05:15 PM

Originally Posted by iali76

Can someone update this thread as I would like to know if t-mobile finally switched their 3g/4g frequencies to use any compatible ATT device? if,so, can I use my unlocked i747 with tmo 4g prepaid plan?

Not yet. Only in select areas is the 3G upgrade complete.
4G/LTE support will come next year.

An unlocked Samsung Galaxy S III (i747) will work once everything is completed.
This device works on some parts of the upgraded 3G network with a T-Mobile line,

Check this link for updates.
http://airportal.de/

**bmold86** · 03-19-2013, 07:17 AM

Sorry to reopen an old topic but does anybody know if it's possible to find a map of where at&t has 850 3G coverage and where they have 1900 3G coverage and where they overlap? I live in a rural area (Vermont, 05850) and not sure if one is more prevalent than the other.

**i0wnj00** · 03-19-2013, 11:34 AM

Originally Posted by bmold86

Sorry to reopen an old topic but does anybody know if it's possible to find a map of where at&t has 850 3G coverage and where they have 1900 3G coverage and where they overlap? I live in a rural area (Vermont, 05850) and not sure if one is more prevalent than the other.

http://maps.mobileworldlive.com/netw...nited%20States

I'm not sure of the NEK region since I haven't driven through this area in a long time, however I would use devices with 3G 850 MHz seeing that this was the first band AT&T deployed 3G in Vermont. I'm going to bet that either Newport or St J will both have 3G 1900/850 by now, however the 3G 1900 MHz signal from either town won't likely reach you. I'm not sure about the site near your town or the one located inside Darling State Park, but the 1900 MHz overlap will be small with gaps.

**dmarkson** · 03-19-2013, 11:36 AM

AT&T was handed the Unicel 850 GSM network for all of VT when Verizon was forced to divest it several years ago. They had very littlle (if any) 1900 built out at the time. There may be pockets of 1900 (read Burlington and around the NH border on I-89) but figure 850 for the most part. Based on your zipcode and looking at the map it's definately a 850 area. Look over into NH where AT&T is 1900 only and you can see what happens to coverage!