11 Replies Latest reply: Oct 14, 2016 5:23 AM by drnewcomb2 RSS

    Service issues after switching from AT&T


      I've switched from AT&T to T-Mobile and I'm seeing low to no coverage in areas T-Mobile says I should have coverage (tower is only 4miles away). I think it does have to do with the switch even though my device is compatible (iPhone 6) due to the carrier in the status bar still showing AT&T most of the time. I've done a full restore of the device, reseated the SIM card, etc and still see coverage issues. I've even gone into Settings > Carrier and manually specified T-Mobile which does fix the AT&T status bar issue but not the service issue...


      i feel like the APN Settings are the culprit here but T-Mobile doesn't allow those to be changed on iOS 8 or later. The only thing I can think of would be to jailbreak and use those utilities to access the APN. Any other ideas? Surely someone else out there has ran into this or something similar.

        • 1. Re: Service issues after switching from AT&T

          A couple of things here;


          First while compatible it isn't fully capable to use all of T-Mobile's frequencies.  Apple saw fit to put 20 LTE bands on the 6 and while they got the 2 high band LTE frequencies they left out the one T-Mobile uses (spectrum bought from VZW) along with some of the smaller US carriers which was Band 12 (700 A block).  Personally I believe Apple did it based on a fear that AT&T initiated then backed off and started supporting Band 12 phones on their network but originally claimed that the having one band for 700 wasn't possible due to issues with A block and the fact that ran up against the TV bands.  In reality and they were called out on it and that's why they caved an updated their towers to support both band 12 and 17  because the FCC was about to crawl deep into it and they knew it wasn't legitimate but rather their attempt to not have to allow roaming on their network because "devices weren't compatible".  Anyway the 6 doesn't have Band 12 which is T-Mobile's low band spectrum, low band spectrum carries farther and penetrates buildings, trees and etc better. To give you an example of how much better a general rule of thumb is it takes 4 high band towers to cover 1 low band tower.


          Second it wasn't T-Mobile that locked the APN on the iPhone it was Apple.  All other devices that T-Mobile sells the APN is readily adjustable and in some cases needed when traveling internationally and roaming especially in smaller countries that have not updated their countries internet to support IPv6 so you need to manually adjust the APN to IPv4.  What was Apple's motivation who knows but it is one of the reasons I am not an Apple fan is that when they decide to limit or control what you can change then it's gone or locked or essentially it's Apple's way or the highway.


          I can't tell you what the risk's versus the benefits of jail breaking and iPhone so maybe someone else can jump in on that point but without Band 12 that is already one handicap of the 6 not to mention iPhones are notorious for their antenna's not being the greatest but since it supported AT&T's low band LTE it wouldn't have as much of an impact with AT&T as it does with T-Mobile since they chose to leave T-Mobile's low band out even though T-Mobile has been selling iPhones since I believe the 5.

          • 2. Re: Service issues after switching from AT&T

            I do appreciate the response here but most of it sounds conspiracy theory based and not much fact other than the band issue. As far as that goes, it doesn't address the issue of the status bar showing AT&T when there is a T-Mobile SIM card in. It might lead to slower 2G/3G speeds instead of LTE but also doesn't explain low to no signal with a tower so close.


            Againg, I do appreciate the thought but still waiting for something that addresses the original question.

            • 3. Re: Service issues after switching from AT&T

              Well the deal with AT&T and them arguing against band 12 is public record and then the unexpected 180 just as the FCC announced it was going to start looking at.


              As for why Apple didn't include Band 12 yes that is "conspiracy theory" but one does have to wonder why when T-Mobile (and others) had Band 12 spectrum, all other devices on T-Mobile were getting band 12 capable radios not to mention that Apple put a radio that supports 20 other LTE bands (just not 12) there has to be some reason wouldn't you agree??


              Yes the antenna (other than the one on the 4 that Apple admitted to) is anecdotal but I have been helping folks on this site for quite a few years and if you search signal related issues 75%+ are iPhone so take that for what you will.


              Last thing from my understanding there are what they call "carrier" updates for iPhones that have specific features that are tailored to a particular carrier like say Wi-Fi calling which while was added to iPhone in IOS 8 I believe some carriers like AT&T and VZW didn't want its customers to even see the option so it hidden.  Have you done a "carrier update"?  Also if you go to networks and try to manually select the T-Mobile network does the AT&T go away?

              • 4. Re: Service issues after switching from AT&T

                Yes, actually. Manually selecting T-Mobile from the list does set it to the correct carrier but doesn't improve the issue overall with reception. Also, per T-Mobile's documentation I am running their latest carrier bundle version 25.2.


                I'm still leaning towards APN Settings being the culprit here but hoping someone else has had a similar experience to verify before I go that route.

                • 5. Re: Service issues after switching from AT&T

                  The APN settings have nothing to do with the phone showing AT&T or T-Mobile. Where are you located?

                  • 6. Re: Service issues after switching from AT&T

                    East Central Indiana

                    • 7. Re: Service issues after switching from AT&T

                      Well, Muncie south there's some band 12 deployment. Portland north, no band 12.

                      • 8. Re: Service issues after switching from AT&T

                        how about roughly 5 miles west of Winchester?

                        • 9. Re: Service issues after switching from AT&T

                          OK. Let's say Maxville. T-Mobile seems to have a mid + low band tower located in Winchester. My estimate is that decent coverage for an iPhone 6 would reach out to about N500W. Maybe N400W. Any farther west would be getting into really fringe coverage. Coverage with a band-12 phone would be substantially farther but things are pretty thin until you get to Muncie. It looks like AT&T roaming is LAC-unblocked in this area.


                          So, what's probably happening is that you're running out of T-Mobile signal and roaming over to AT&T. The problem is two fold:

                          1) The iPhone 6 does not support T-Mobile's band-12 service which would give you longer range from the tower in Winchester.

                          2) No towers between Muncie and Winchester? 22 miles? Really? What year is this; 1990? T-Mobile really needs to up their game in your area. People don't use bag phones any more. T-Mobile has low band they need to deploy a usable network.


                          You might do somewhat better with a phone that has band-12. You might also want to view your move to T-Mobile as a noble experiment with a negative result. I know that if I lived in your area, I'd be hard pressed to justify T-Mobile service.

                          • 10. Re: Service issues after switching from AT&T

                            This is very helpful! I'm saving an upgrade until next year as I couldn't justify it this year but I do have an iPhone 6SE that appears to support band 12. I may experiment with that for now but my opinion has been that T-Mobile likely needs more coverage here.


                            Another unfortunate event came when I tried alerting T-Mobile to this as just feedback and the response twice. Ow has been to troubleshoot the issue instead of passing it along. Overall I'm saving about $20 per month and have "unlimited" data that I didn't have with AT&T. What have I done...

                            • 11. Re: Service issues after switching from AT&T

                              The SE does have band 12 and should give you an idea of the difference between having combined mid and low-band service and just mid-band service. Do you know how much data you actually use each month?