cfong

    I have a Samsung Note 4 that supports band 12. In my office location, on north side of the building, I get band 12. On south side, I get band 4. I know the band from *#0011#.

     

    Band 4 works well, band 12 works only when it wants to (and very poorly even when it works). It's not that I don't get signal, the band 12 signal is 4-bar strong (4G LTE), stronger than band 4, but band 12 either is very slow (<1 Mbs) or not working at all. I cannot even load the google front page while the phone shows 4 bar 4G LTE signal, it's not just slow, it's ZERO servicde, dispite the 4 bar signal strength.

     

    Please help. My address: 6801 North Haggerty Road, Canton, MI 48187. Thanks!

      All replies

      • stevetjr

        Re: band 12 with 4 bar signal but no service at all

        That is weird on a number of fronts and sounds like your phone might be getting hung up shifting between Band 4 and 12.  You should only see Band 12 when your phone can't maintain signal on Band 4 since Band 12 is essentially a "back up channel".  The reason for this is that Band 12 is only a 5x5 MHz channel where as in most markets Band 4 is 10x10 at a minimum or 20x20 in some markets.  Band 12 also because of it's lower frequency doesn't have the same bandwidth as the higher bands.   If you are showing 4 bars on Band 12 usually that means you should be able to get signal on Band 4 if 12 is that strong. 

         

        Are there other areas you know you will get Band 12 to roll in?  If so are they just as slow or no service?  If it works on Band 12 elsewhere could just be a tower issue, backhaul issue for that tower or just a lot of congestion on that tower and you would want to get a ticket put in for that particular tower.

          • cfong

            Re: band 12 with 4 bar signal but no service at all

            Steve,

             

            Thank you very much for writing back. I guess I didn’t make things perfectly clear. My office building is very large and long, it runs in north/south direction. So when I said north side and south side, I really should have said north end

            and south end.

             

            I don’t believe my phone is hung up between band 12 and 4, because when I entered *#0011#, it clearly showed it was band 12, bandwidth 5MHz. I don’t believe T Mobile’s “back up channel” approach would work because the phone always hooks

            to the stronger signal. It doesn’t know what it should prefer band 4 as long as there is any signal. If band 12 signal is stronger, it will connect to band 12, I have no way to control this. Before the band 12 was active in this area, I had band 4. Despite

            the weak signal, the speed was actually descent. After band 12 showed up, my phone goes to band 12 because the signal was stronger, I have no way to turn off band 4 on  my phone.

             

            I understand that band 4 has smaller bandwidth and therefore is slower. I can tolerate that. However, 4-bar signal with no data service whatsoever is wrong. And it’s not just my phone, it’s all the T-mobile phones around me, same deal.

            Some of my coworkers are considering leaving T mobile for this very reason.

             

            My friend’s house is also covered by band 12. Over there the speed is slow for 4g LTE (about 2 MB per second), actually this barely meets 3G speed standard. But at least it works. There they don’t have the “no service at all” issue.

            Thank you,

            Ching

          • cfong

            Re: band 12 with 4 bar signal but no service at all

            Steve,

             

            Thank you very much for writing back. I guess I didn’t make things perfectly clear. My office building is very large and long, it runs in
            north/south direction. So when I said north side and south side, I really should have said north end and south end. Again, when I am at the south end, the phone shows that it was connected to band 4. When I am the north end, it shows that it was connected to band 12.

             

            I don’t believe my phone was hung up between band 12 and 4, because when I entered *#0011#, it clearly showed it was band 12, bandwidth
            5MHz. I don’t believe T Mobile’s “back up channel” approach would work because the phone always hooks to the stronger signal. It doesn’t know that it should
            prefer band 4 as long as there is any signal. If band 12 signal is stronger, it will connect to band 12, I have no way to control this. Before the band 12 was
            active in this area, I had band 4. Despite the weak signal, the speed was actually descent. After band 12 showed up, my phone goes to band 12 because the
            signal was stronger, I have no way to tell my phone to not use the "backup channel".

             

            I understand that band 12 has smaller bandwidth and therefore is slower. I can tolerate that. However, 4-bar signal with no data service whatsoever is wrong. And it’s not just my phone, it’s all the T-mobile phones around me, same deal. A few older phones actually work better, because they don't support band 12, so they are hanging onto the weak signal from band 4. Some of my coworkers are considering leaving T mobile for this very reason.

             

            My friend’s house is also covered by band 12. Over there the speed is slow for 4g LTE (about 2 MB per second), actually this barely meets 3G
            speed standard. But at least it works. There they don’t have the “no service at all” issue.

             

            In my opinion T-Mobile's Band 12 strategy is a dud. There is a minimum speed standard a service has to meet before it can call itself 4G LTE. T-M's band 12 clearly doesn't meet it, in its best days.

            • drnewcomb2

              You have T-Mobile sites within 2 km of you, north and south. The one to the north has band-12. I suspect the situation is that the downlink signal (from the tower) is strong enough to register on your phone but the uplink from the phone is not strong enough to complete the link back to the tower. Unfortunately, T-Mobile can't guarantee that architects won't design buildings like Faraday cages, preventing RF signals from getting in or out. If your phone works outside the building, they've done their jobs.

               

              You might want to try a phone that has Carrier Aggregation but there's no guarantee it will work any better.

                • cfong

                  Re: band 12 with 4 bar signal but no service at all

                  I have tried the phone at the north end parking lot, same thing, 4 bar signal, but when there is no service indoors, there is no service outdoor either. It's not always without service. Early in the morning like before 8AM, it usually works. After 9AM, it usually stops working, with the phone at exactly the same spot, namely my office desk. it's not hte signal strength, it's that tower not providing service. Unfortunately near the north end, the band 12 tower has a stronger signal then the band 4 at the south end. My phone is stuck to it.

                   

                  Couldy you let me know where you found out the town location near my office? Thank you.

                    • drnewcomb2

                      CellMapper.net is a crowd-sourced map of cellular towers and signals, based on data collected by users of the Android CellMapper app.

                       

                      It's interesting that you have these issues outside. I would not have expected that. A strong signal outside but no service is indicative of signal congestion. What I might suggest you do, when this happens outside, switch your Note 4 into band-4 and try again. T-Mobile has lots of spectrum in Wayne Co. and is probably running 20x20 LTE on band-4, but their band-12 signal is only 5x5 LTE, Being stuck with just band-12 can really limit your speed. I'm not 100% sure that your Note 4 is able to use Carrier Aggregation between band-12 and band-4. From what I've read, it should. What's the exact model number and have you done all the required updates to the firmware?