Database Info

Investigation: The mysterious 850 MHz band

I want to figure this out once and for all.
What services does this phone support on the 850 MHz band?
The big question is whether UMTS/HSPA works. NYC area has amazing 850 band coverage on AT&T.
If I were to put a prepaid AT&T SIM in my phone, set my phone to only operate on the 850 MHz band, and set the proper APNs (necessary for 3G?); would I be able to get data beyond EDGE?

Only one way to find out...

There's no mystery to it if you read through the [GUIDE] Set up Verizon Galaxy S3 as World GSM Phone (confirmed working) thread and the [BOUNTY] ($205 so far) Enable HSPA+ on 1900 MHz / 1700MHz for VZW Galaxy S3 i535 threads completely....
With the radio software verizon has on the phone, the galaxy s3 is quad band GSM (850/900/1800/1900) and single band WCDMA (2100).
We don't know if it has the hardware for WCDMA 850/900/1900 and until now, nobody has successfully flashed a different radio due to the bootloader lock. Keep an eye on the "enable WCDMA 1700/1900" thread for updates.
And just to answer another question that you might have, when my S3 was rooted and set up to work in Germany, I tried both T-Mobile and AT&T sim cards here in town. The problem with the S3 is that even if you try to select a different WCDMA band in the field test menu, the radio firmware will not allow you to change it from 2100. So in an area with T-Mobile PCS (1900) and AT&T PCS/CELLULAR (1900/850) WCDMA, each test I tried only ran on EDGE.
Sent from my Nexus 4 using xda premium

Wow... That really sucks.
So, there's literally no way to get 3G outside of Verizon aside from MetroPCS EVDO?

LLStarks said:
Wow... That really sucks.
So, there's literally no way to get 3G outside of Verizon aside from MetroPCS EVDO?
Click to expand...
Click to collapse
The first step is to experiment with different radio files, as one user in the 1700/1900 thread wants to do, but we need to get the secure-boot/bootloader unlocked so those files can be written.
Phones like the Rezound had the hardware for Quad-band WCDMA (3g), but took a radio file flash to make it work. The reason there is a bounty is because we -think- the Verizon S3 has the hardware, it will just take some work to get the software on the phone to talk to that hardware.

I know. I've been following the thread.
Was a little unsure of the details regarding frequencies.
As far as I understand, they're at a dead end. They need JTAG/UART to continue without worrying about bricks.

LLStarks said:
I know. I've been following the thread.
Was a little unsure of the details regarding frequencies.
As far as I understand, they're at a dead end. They need JTAG/UART to continue without worrying about bricks.
Click to expand...
Click to collapse
Yeah, and sadly, I lack the skills and the bounty probably isn't enough to attract a dev with JTAG and a phone to fiddle with to solve our issue

Verizon cdma is ran by nortel dual urban base stations the frequencies are 810-910 and 1840-2000mhz. The LTE is 690-760mhz 1x means that your on 850. 3g means your on 1900 or 850 depending on how far away from the site you are, and 4g means your on LTE. The LTE base station is ericsson but speeds will vary depending on whether or not the site is on fiber or T1 transport. Normally they keep the pre pay customers on the nortel dual urban... Oh by the way we are starting to decommission the lucent cdma on metro pcs sites and convert them to t-mobile GSM but luckily metro uses ericsson for LTE too so there's hope.
Sent from my SCH-I535 using xda app-developers app

[Q] 1800MHz LTE Band

This phone is the first phone Verizon is selling (except the iPhones) that has the 1800MHz LTE Band (band 3).
When I saw this I was particularly excited as I visit Australia often and that's the band Telstra uses. I am currently in Australia now, and I am unable to pick up any LTE on this phone. I have gone through every possible mode in the phoneinfo app, but none will get any LTE signal.
I am using a Telstra SIM that has LTE service and I put in the correct APN settings.
The only possible explanation that comes to mind is that Verizon is blocking the 1800MHz LTE band from being used, just like the S4 came with AWS but only a software update pushed later on was able to unlock that band. If that were the case, is there any way around it?
Any other ideas why it's not working?

I tested my SIM in the same location in a iPhone and it got lte
Sent from my HTC One M8 using Tapatalk

levilib said:
This phone is the first phone Verizon is selling (except the iPhones) that has the 1800MHz LTE Band (band 3).
When I saw this I was particularly excited as I visit Australia often and that's the band Telstra uses. I am currently in Australia now, and I am unable to pick up any LTE on this phone. I have gone through every possible mode in the phoneinfo app, but none will get any LTE signal.
I am using a Telstra SIM that has LTE service and I put in the correct APN settings.
The only possible explanation that comes to mind is that Verizon is blocking the 1800MHz LTE band from being used, just like the S4 came with AWS but only a software update pushed later on was able to unlock that band. If that were the case, is there any way around it?
Any other ideas why it's not working?
Click to expand...
Click to collapse
Bit of a necro-post, but I asked both HTC and Verizon associates and they said that it should work...so don't know if some bad information has been passed my way or GSM/LTE is just being funky (I do remember reading that has been, or was, a problem)

Can we unlock the 3G and 4G bands of Moto G 2015?

Hi,
I brought a Moto G from India, before coming the US for doing my masters.
The thing is here it does not pick up 3G or 4G bands. It just works on EDGE.
I wanted to ask if i can use the QPST method to unlock the bands? because I can see no information on it in the forums(for this phone). I am especially confused since it says nothing about dual sim phones and this is the dual sim variant of moto G
It would be great if someone would guide me how i could unlock the bands on my phone.
Regards,
Naved.

I'm almost a 100% sure this wont work but try installing a USA stock rom and a USA stock kernel. But I think the problem is with Sim card though.

Thanks for the help man. I am currently on T-Mobile planning to switch to at and t soon. You think that it'll at least pick up 3g after that?
Sent from my MotoG3 using XDA Free mobile app

Dear Akonsand, finally do you know if I can use the QPST method to unlock the bands of the Moto G3 (XT1541)?
I have the same problem that you...

I'm bumping this just in case there are some news on the subject.
I'm stuck on EDGE with an XT1541 in Argentina and i'm not really sure of what to do... Is there some sub-forum with phone exchanges around the world?
Maybe someone's interested on a trade!
There were some successful attempts at unlocking the bands on the Moto E 2015, but for now there's no hope for the G...
How do you guys see it? Do we have any chance? Should we wait?
Thanks everybody!

Very interested as I have a xt1550 but am on o2 UK and would like to enable lte for this carrier

akonsand said:
Hi,
I brought a Moto G from India, before coming the US for doing my masters.
The thing is here it does not pick up 3G or 4G bands. It just works on EDGE.
I wanted to ask if i can use the QPST method to unlock the bands? because I can see no information on it in the forums(for this phone). I am especially confused since it says nothing about dual sim phones and this is the dual sim variant of moto G
It would be great if someone would guide me how i could unlock the bands on my phone.
Regards,
Naved.
Click to expand...
Click to collapse
I am a little confused here... Your Indian model phone should get 3G in the US, but not LTE (I hate it when people say "4G", technically speaking even LTE isn't 4G but that is for another thread), in fact, assuming you have the correct SIM and APN settings, your model should get HSPA+ speeds. LTE is out though... let me explain
3G (HSPA/HSPA+) in the US is 850Mhz and 1900Mhz, in India it is 800Mhz and 1800Mhz, the Moto G supports all 4 of these bands, so it should work in the US just fine.
In the US, several bands are used for LTE such as 2, 4, 5, 12, 13, 17, 25, 26, and 41 (granted some bands are very limited or carrier specific), but in India LTE use is exclusively Band 40 by both Aircel and Airtel, and the LTE setup in the Moto G is specific for those countries and does not inter-operate.
So, long story short, with a GSM US carrier SIM and correct APN setup, you should get 3G HSPA+ data connections with no issues on your Indian Moto G, which is probably good enough for most uses and can exceed 8mbps down speeds in many areas.

acejavelin said:
I am a little confused here... Your Indian model phone should get 3G in the US, but not LTE (I hate it when people say "4G", technically speaking even LTE isn't 4G but that is for another thread), in fact, assuming you have the correct SIM and APN settings, your model should get HSPA+ speeds. LTE is out though... let me explain
3G (HSPA/HSPA+) in the US is 850Mhz and 1900Mhz, in India it is 800Mhz and 1800Mhz, the Moto G supports all 4 of these bands, so it should work in the US just fine.
In the US, several bands are used for LTE such as 2, 4, 5, 12, 13, 17, 25, 26, and 41 (granted some bands are very limited or carrier specific), but in India LTE use is exclusively Band 40 by both Aircel and Airtel, and the LTE setup in the Moto G is specific for those countries and does not inter-operate.
So, long story short, with a GSM US carrier SIM and correct APN setup, you should get 3G HSPA+ data connections with no issues on your Indian Moto G, which is probably good enough for most uses and can exceed 8mbps down speeds in many areas.
Click to expand...
Click to collapse
Hey thanks for the reply man.
I think even HSPA or HSPA+ might not work for me on this phone. I am using a T Mobile family plan here, and comparing th bands given on the website:
"4G (HSPA+)
With 4G, theoretical maximum download speeds range from 21 Mbps up to 42 Mbps. You can take advantage of incredibly fast download speeds, and even use voice and data services at the same time.
Frequencies: Band 2 (1900 MHz), Band 4 (1700/2100 MHz)
3G (HSPA)
With 3G, theoretical maximum download of 14 Mbps. With 3G, you can use voice and data services simultaneously.
Frequencies: Band 4 (1700/2100 MHz)"
and the bands my phone supports(from the motorola website)
"Moto G (XT1550)
LTE (1, 3, 7, 8, 28,40) UMTS/HSPA+ (900, 2100, 850 MHz)
GSM/GPRS/EDGE (850, 900, 1800, 1900 MHz)"
It seems that the uplink is unsupported by my phone and so the phone is unable to use the HSPA/HSPA+ bands. I think the only way to use it is to unlock the 1700 MHz band on my phone.
(BTW Tmobile quotes HSPA+ as 4G and thats hilarious lol)

akonsand said:
Hey thanks for the reply man.
I think even HSPA or HSPA+ might not work for me on this phone. I am using a T Mobile family plan here, and comparing th bands given on the website:
"4G (HSPA+)
With 4G, theoretical maximum download speeds range from 21 Mbps up to 42 Mbps. You can take advantage of incredibly fast download speeds, and even use voice and data services at the same time.
Frequencies: Band 2 (1900 MHz), Band 4 (1700/2100 MHz)
3G (HSPA)
With 3G, theoretical maximum download of 14 Mbps. With 3G, you can use voice and data services simultaneously.
Frequencies: Band 4 (1700/2100 MHz)"
and the bands my phone supports(from the motorola website)
"Moto G (XT1550)
LTE (1, 3, 7, 8, 28,40) UMTS/HSPA+ (900, 2100, 850 MHz)
GSM/GPRS/EDGE (850, 900, 1800, 1900 MHz)"
It seems that the uplink is unsupported by my phone and so the phone is unable to use the HSPA/HSPA+ bands. I think the only way to use it is to unlock the 1700 MHz band on my phone.
(BTW Tmobile quotes HSPA+ as 4G and thats hilarious lol)
Click to expand...
Click to collapse
Most us carriers say HSPA+ is 4G...
Tmobile is great in many regards, except if you have an international phone like the Moto G and they do not have the correct bands implemented in your area, which it appears they do not... Honestly, consider moving to AT&T Wireless or an AT&T based MVNO like Cricket, Straight Talk AT&T, or Go Phone, it might cost a little more but you could get HSPA+ with no issues. 850Mhz is AT&T's primary HSPA/HSPA+ frequency, and 1900Mhz is added to congested areas, but this varies by area... before going all in I suggest trying a SIM from a buddy or go the AT&T (corporate) store and ask to test a SIM just to be sure. But regardless you should get UMTS/GSM speeds on AT&T, which is way better than Edge, averaging anywhere from 500kbps-2mbps.
If TMo is essential or you can't change for whatever reason or live without HSPA+/LTE, consider getting a Blu phone or Moto E locally, they are relatively inexpensive (under $150) and are not amazing but will probably do the job.

acejavelin said:
Most us carriers say HSPA+ is 4G...
Tmobile is great in many regards, except if you have an international phone like the Moto G and they do not have the correct bands implemented in your area, which it appears they do not... Honestly, consider moving to AT&T Wireless or an AT&T based MVNO like Cricket, Straight Talk AT&T, or Go Phone, it might cost a little more but you could get HSPA+ with no issues. 850Mhz is AT&T's primary HSPA/HSPA+ frequency, and 1900Mhz is added to congested areas, but this varies by area... before going all in I suggest trying a SIM from a buddy or go the AT&T (corporate) store and ask to test a SIM just to be sure. But regardless you should get UMTS/GSM speeds on AT&T, which is way better than Edge, averaging anywhere from 500kbps-2mbps.
If TMo is essential or you can't change for whatever reason or live without HSPA+/LTE, consider getting a Blu phone or Moto E locally, they are relatively inexpensive (under $150) and are not amazing but will probably do the job.
Click to expand...
Click to collapse
Cool Alright. I actually had a chance to join AT & T family plan but didn't join it because T-mobile was giving more data :facepalm:
Ill see if i can switch to an AT & T network.
Thanks for your help one again man!

akonsand said:
Cool Alright. I actually had a chance to join AT & T family plan but didn't join it because T-mobile was giving more data :facepalm:
Ill see if i can switch to an AT & T network.
Thanks for your help one again man!
Click to expand...
Click to collapse
Try to test it first, just to be sure.
Sent from my MotoG3 using Tapatalk

akonsand said:
Hi,
I brought a Moto G from India, before coming the US for doing my masters.
The thing is here it does not pick up 3G or 4G bands. It just works on EDGE.
I wanted to ask if i can use the QPST method to unlock the bands? because I can see no information on it in the forums(for this phone). I am especially confused since it says nothing about dual sim phones and this is the dual sim variant of moto G
It would be great if someone would guide me how i could unlock the bands on my phone.
Regards,
Naved.
Click to expand...
Click to collapse
so far i know these are hardware specs and cannot be unlocked or changed.i mean to say moto g 2015 has different variants based upon hardware specs of their band support

If you started using att with your xt1550 ..how is it? Do you get 3g or lte?

I didn't start using it. Currently stuck with a group plan.. But I tried using a friends sim card.. 3g does work well with at n t.
Sent from my MotoG3 using XDA Free mobile app

Thanks for letting me know... I wish there was a way to get 'lte' ...someone has to come up with a way to unlock the bands lol. Thanks

I am currently having the samw problem, i bought a moto g which lte and 3g bands do not work in argentina. I tried the qpst method, but i got stuck in step 12 of the guide. If someone could make it work and explain how they did it, it would be awesome.

KentianAylomen said:
I am currently having the samw problem, i bought a moto g which lte and 3g bands do not work in argentina. I tried the qpst method, but i got stuck in step 12 of the guide. If someone could make it work and explain how they did it, it would be awesome.
Click to expand...
Click to collapse
Same here...I am trying qpst also but rf.nv manager keeps getting an error for me. Maybe we can work together on this. I also can't figure out the hidden menu..unless its *#*#4636#*#*

KentianAylomen said:
I am currently having the samw problem, i bought a moto g which lte and 3g bands do not work in argentina. I tried the qpst method, but i got stuck in step 12 of the guide. If someone could make it work and explain how they did it, it would be awesome.
Click to expand...
Click to collapse
hello i have the same problem with my moto g, i like to know if somebody have a solution (lo compre en andorra y aca en argentina no funciona, queria saber si aderribo o kentianAylomen lo habian resuelto mi correo es [email protected])

francoferrer said:
hello i have the same problem with my moto g, i like to know if somebody have a solution (lo compre en andorra y aca en argentina no funciona, queria saber si aderribo o kentianAylomen lo habian resuelto mi correo es [email protected])
Click to expand...
Click to collapse
Hey , I'm from argentina too and have the same problem. Could someone fix it? (hablemos en castellano)

The same problem with rf.nv manager. It always stops when I want to setting the COM. I edited some things of the program... Didn't work.

LG Phoenix 2 (K371) Network mode issue

Hello,
I've got a LG Phoenix 2(K371) phone that I bought from Bestbuy and unlocked through AT&T
The phone is supposed to support the UMTS B1(2100 Mhz) frequency (as stated in specs).
I'm in North Africa right now for a business trip and unfortunately I wasn't able to get any 3G data with the local carrier that uses the UMTS 2100 Mhz frequency, I'm stuck with only 2G while my other phone works just fine.
I tried to change my Network Mode from 4G to 3G but the Network mode menu is missing!!!!!!
My questions are:
1- Does the K371 really supports the UMTS 2100 Mhz frequency ?
2- How can I change my Network mode from 4G/Lte to 3g/WCDMA?
Thanks

Did you ever get this sorted out? I am in Germany and can only get 2G also.

Same here in the UK! Only 2G.
My understanding is that either the official specifications of the phone are wrong - it doesn't support the HSDPA frequency of 2100 MHz, or (most likely) this frequency is disabled in the phone software settings since [email protected] doesn't use this frequency in the US. In any case it is very frustrating: I bought this phone convinced it is going to work while I am travelling in Europe, but obviously it doesn't as 2G data connection is useless.

Same problem in SE Asia. Phone doesn't have the right LTE bands but HSPC should work. Only getting 2G. No option in the hidden menu to change the modem RAT settings that I can see. *#546368#*371#
Anyone have any luck using the k371 overseas?

Same here...
I tried every single method I know in hopes that I could root the phone, but no luck!!!
I believe at&t disabled the said frequencies....
Our only bet is a proper root, and a custom rom..

any update on no UMTS 2100Mhz?

any solutoion on this issue?

I have found a solution. I am using it outside the US. I contacted my cellular provider, gave them the phone name (LG K371) and they sent me a text message with automatic settings for their data network. As soon as I opened it, I got a message like "data settings have been updated" and now it works on 3G and 4G without any issues. You may also be able to find these data configuration settings on your cell service provider's web site.

Seriously???
Please let me know is it AIRTEL service? since i am from INDIA.
we have the same problem in 2 mobiles..

Hmmm
I tried of calling and received setting for MMS , GPRS, INERNET but still i m seeing 2G symbol as E - edge detection
Please help me

Hi this is sainath
am also facing same problem, any one got solutions
please give reply.

tromal said:
Hello,
I've got a LG Phoenix 2(K371) phone that I bought from Bestbuy and unlocked through AT&T
The phone is supposed to support the UMTS B1(2100 Mhz) frequency (as stated in specs).
I'm in North Africa right now for a business trip and unfortunately I wasn't able to get any 3G data with the local carrier that uses the UMTS 2100 Mhz frequency, I'm stuck with only 2G while my other phone works just fine.
I tried to change my Network Mode from 4G to 3G but the Network mode menu is missing!!!!!!
My questions are:
1- Does the K371 really supports the UMTS 2100 Mhz frequency ?
2- How can I change my Network mode from 4G/Lte to 3g/WCDMA?
Thanks
Click to expand...
Click to collapse
Sorry for a late reply, but here's the real scoop about the LG K371 (AT&T)
First, being a "cheap" LG phone, there are very few bands actually included, and they only cover the main (not all) AT&T US frequencies, therefore it's no surprise that doesn't work on all overseas carriers. Again, they are covering only major US bands, and despite what it shows on the box or specs it may not be always true. B1 (2,100Mhz) band has different sub-bands, therefore it doesn't mean that the US B1 will work on an overseas B1, let alone the air-interface (2G/3G/4G/LTE) may not all be supported even if this sub-band exists.
Second, being that it's an AT&T phone, they are knows to load firmware with major restrictions for band selection called RAT Restrictions, which cannot be undone unless you can reflash it with a non-customized firmware, but you can't do that either due to the locked bootloader. A better option is to always go with the un-customized or Tmobile K7/K8 because they always have a lot more bands enabled than the AT&T version. Better yet, go with a Samsung which have more bands even on the AT&T models.
Bottom line, "cheap" phones along with AT&T restrictions will not work everywhere, despite the specs, and there's nothing you can do about it.
And my favorite old adage is "You get what you pay for!" LOL

PLEASE HELP! Network no longer connecting on new Moto G3 TE (merlin)

Please help! Network issues - will *not* connect at all anymore!
I just bought this phone (XT1557) just over a week ago. I unlocked it and installed TWRP then made a backup. Then I installed AOSP Extended and was enjoying learning about it and using the phone. I'm using H20 Wireless (they use AT&T network). Everything seemed to be great for about a week and I was very happy with my new phone. However, just yesterday, while traveling in the US and using the phone (for maps/navigation, gasbuddy, facebook, etc. - it was also charging from a car charger at the same time) we hit a patchy spot in the signal and I couldn't get the network to reconnect. After a few minutes (still traveling) for a split second the network icon flashed as having a decent signal, but then it went off again and *NEVER CAME BACK*! Nothing I've done since then has been able to get the network to come back on my phone.
Here's what I've tried:
* toggling airplane mode, toggling preferred 4G/LTE, or 3G, or 2G
* Reboot;
* safe mode;
* tried sim in the other sim card slot
* tried another sim in my phone that was currently working at the time in Moto G 2nd gen, in both sim slots - still not working in my phone; tried my sim in that phone and it's working in that phone (so not a sim card problem)
* tried *#*#4636#*#* - still shows "emergency calls only" and the signal strength does fluctuate depending on where I move around (see screenshots), tried bunch of different radio bands, tried turning off and on radio power, tried changing preffered network type (to lots of different ones)
* tried dirty flashing AEX again and newest GApps
* tried clean flashing AEX and newest GApps
* tried clean flashing Lineage OS 14.1 and newest GApps.
* flashed only the original modem firmware from MM stock rom (provided here at xda)
* restored my nandroid backup to stock rom (6.0.1)
NONE of these things have worked! PLEASE help! Is there any way I can test this to see if it's a hardware issue? (Though it seems strange for hardware to fail after just 1 week... and there's no warranty since I unlocked it, but I bought it new on ebay anyway, so no warranty.)
Any help you can give will be so appreciated. Nothing else on the phone seems to have a problem (wifi, etc., all seem to be working). The phone didn't even act weird when the network stopped working -that was the only thing. Everything else on the phone still acted like normal without even a reboot. If you've ever even heard of this happening, please let me know. I can't find any other info on what to do on the internet and I've searched all over. If you can help me (or even try), I'll give you so many thanks, as many as it lets me give on here! Thank you for even considering helping me - I really want this to work!

I don't know for sure if this is the case, but here is a possibility...
There is no 2G (GSM) service on H2O/AT&T, period, it was shutdown in December 2016.
For 3G AT&T uses 850Mhz & 1900Mhz HSPA(+), but it varies which one based on licensing and network saturation, among other things... Not everywhere has both (in fact, both only appear in select high-penetration markets)... the XT1557 supports HSDPA 850/900/2100, note that 1900Mhz is NOT a supported frequency, yet it is quite common in AT&T's network... It is a possibility that you left an area with 850Mhz service, and entered an area with 1900Mhz service and now have no service, literally. The service is there for AT&T/H2O, but your phone doesn't support the frequency in that area.
LTE bands support by the XT1557 are LTE band 1(2100), 3(1800), 7(2600), 8(900), 28(700), 40(2300), but none of those are compatible with AT&T.
It is entirely possible that you just don't have service, because there is NO service your phone is capable of getting because either that frequency isn't available or it's used by another carrier in that area (and H2O has no roaming from AT&T's core network to partner networks like AT&T post-paid service).
Just a possibility... but basically you have a device that only supports a portion of the network you are trying to use.

acejavelin said:
I don't know for sure if this is the case, but here is a possibility...
There is no 2G (GSM) service on H2O/AT&T, period, it was shutdown in December 2016.
For 3G AT&T uses 850Mhz & 1900Mhz HSPA(+), but it varies which one based on licensing and network saturation, among other things... Not everywhere has both (in fact, both only appear in select high-penetration markets)... the XT1557 supports HSDPA 850/900/2100, note that 1900Mhz is NOT a supported frequency, yet it is quite common in AT&T's network... It is a possibility that you left an area with 850Mhz service, and entered an area with 1900Mhz service and now have no service, literally. The service is there for AT&T/H2O, but your phone doesn't support the frequency in that area.
LTE bands support by the XT1557 are LTE band 1(2100), 3(1800), 7(2600), 8(900), 28(700), 40(2300), but none of those are compatible with AT&T.
It is entirely possible that you just don't have service, because there is NO service your phone is capable of getting because either that frequency isn't available or it's used by another carrier in that area (and H2O has no roaming from AT&T's core network to partner networks like AT&T post-paid service).
Just a possibility... but basically you have a device that only supports a portion of the network you are trying to use.
Click to expand...
Click to collapse
Wow, this info could be SOOO helpful! I know this is only a possibility, but it gives me a glimmer of hope when I thought the phone was doomed/broken somehow. I did know my phone was only partially supported (like I knew I probably couldn't get LTE in the US), but I didn't know what all that meant in terms of the other bands. I bought the phone for primary use in Madagascar (which my phone appears to cover all the bands used in Madagascar) but I won't be back there until September, so I'm using the phone in the US in the meantime.
Even though I considered my phone/SIM might not be compatible with the local network, I figured that couldn't be the case since there was clearly a signal in the Moto G2 XT1068 (Titan). However, with what you explained, that might explain some other anomalies. My Titan is also a phone made for international use (where I've used it for years in Madagascar and South Africa and it works great), but when traveling here in the US, I've noticed some anomalies that your explanation might explain (assuming the Titan might also have limited frequencies in use by AT&T/H2O in various parts of the US). For example, in Alaska,there was a time when in southern Alaska (inside passage) my Titan worked great, voice/data, everything (even in some way out of the way places)... then later in central Alaska my wife's phone (an old AT&T phone with a post-paid AT&T sim) got a data signal, and my Titan got a voice signal but no data. It was strange. Didn't work in some airports along the way either (I don't remember which ones, maybe Chicago). It wasn't until we were back in St Louis that the data started working on my Titan right away again, no problem. I figured it was some strange glitch of the OS (CM 13.1) in how it searched/recognized the local network. But maybe it was a limit in the phone's available bands in those regions of the US?
Then again, after I got the new XT1557 (just over a week ago), I transferred my wife's AT&T postpaid SIM to my old titan (XT1068). It was working great, but I never thought to check her mobile data away from wifi (just got busy and never thought to check). At the same time we hit the spotty network connection while travelling 2 days ago (northeastern Missouri, the network was spotty and cutting out on both our phones), that was when my signal went out for good and I saw that hers (AT&T postpaid but now in a Titan XT1068) didn't have a data signal when her network/voice signal came back. That made it very difficult to navigate, so we stopped and refreshed our maps at public wifi. I thought maybe I just needed to update the APN with AT&T, but when I manually input the info they gave me, it still didn't give me a data signal (on the Titan). Now we're in the Des Moines, Iowa area and I'm experiencing everything I've written about with my phone having never recovered a network signal. However, the one anomaly is that, even when I put my H20 sim back in my Titan XT1068 (which I thought was always working in the past, minus that anomaly from the Alaska trip) it gets a good voice signal but still no data signal, just like my wife's prepaid AT&T never got a data signal (that I could see), and even though I know which APN settings to use for H20. I've similarly been beating my head in over the titan's lack of data signal since I refreshed the OS (now on Lineage OS 13.1) since it means we have 2 phones with us on this trip, neither able to get data since leaving northeastern Missouri and mine even worse getting no voice signal at all.
But maybe it means my Titan XT1068 also has limited bands that aren't covered by AT&T/H20's data here even though it's covered by their voice?
The info you've provided so far is excellent. Can you provide similar info about the XT1068's available bands? (I'm not sure where to find all that - I found the original info about XT1557 in the wikipedia page, but Moto G 2nd gen doesn't seem to list the bands specifically. I also don't know where to look for AT&T's specific bands and/or coverage map that might indicate where they have coverage with each band.) If you can provide any of that info it would be so great! But for now, you've extended my hope for my phone. We'll be in Minneapolis area in a few days, so maybe I can try again there. Then we'll be back in St Louis area (where it was working great previously) in just over a week. So at least I'll hold out my hope until then and maybe I'll discover this just isn't the best travel phone for northern US (or other parts of the US). Still, I can't thank you enough for the hope you've given me, even if it is *just* a possibility. It does seem to explain the circumstances.
Sorry for the long story! I just wrote to show that your explanation might really fit well! Your info was so helpful! Please follow-up to tell me if you think the extra info I gave confirms what you wrote. Please also help me find a coverage map for AT&T where I can see where in the US they use specific frequencies. If you can do that for me. Thanks again for being so helpful and explanatory!

@madagascaradam Search by model and then and find the GSMArena page for the device, under the Network section click Expand...
2G bands GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2
3G bands HSDPA 850 / 900 / 1700 / 1900 / 2100
Speed HSPA 21.1/5.76 Mbps
GPRS Yes
EDGE Yes
Click to expand...
Click to collapse
So the Moto G2 you have supports the proper HSPA (but hot HSPA+) bands for all AT&T's 3G frequencies.
Remember that prior to December of last year, likely when you were referencing your Alaska trip, there was AT&T 2G/Edge service nationwide but that has since been shutdown and within the next 2-3 years all 2G GSM and CDMA service in the US will be shutdown from all carriers.
And I used H2O for quite a while, use this APN (there are lots of older settings out there, they don't work quite right, but this is current as of a month or so ago at least):
Name: H2O Wireless
APN: prodata
MMSC: http://mmsc.mobile.att.net
MMS Proxy: proxy.mobile.att.net
MMS Port: 80
MCC: 310
MCN: 410
Authentication Type: Not set
APN type: default,mms,supl,hipri,fota
APN Protocol: IPv4
APN roaming protocol: IPv4
everything else blank, not set or none.

@acejavelin You were totally right! In Minneapolis area I usually had a signal, but not much outside the area. In Iowa no signal at all. But once I got back towards central Missouri the signal has been working great again. So obviously ATT has some regions that use 850 (like in the south) and others further up north that seem to only use 1900 which isn't supported by my phone (XT1557). So, that's not super great for using my phone in the US, but at least I know it's not a problem with my phone.
I also found this map (older, from 2008) which shows where AT&T had 850 MHz frequency and where it had 1900 MHz frequency. It roughly corresponds to my experiences so I definitely think it all adds up. http://www.cellularmaps.com/att_850_1900.shtml
Again, thanks so much for your help!