Develop Bugs

3G on T-Mobile via 1900MHz Band

I recently switched from AT&T to T-Mobile, and like the rest of us was suffering without 3G due to our lack of compatibility with the 1700MHz WCDMA that T-Mobile uses. One of my friends (a T-Mobile employee), however, informed me that it is indeed possible to get 3G by using the 1900MHz band, which T-Mobile is currently re-farming to support WCDMA. This trick is simple and easy, and I've had success with it thus far, albeit only in one location as of yet. There is a downside, however... as long as the trick is in place (as long as your phone is set to "WCDMA only" below), you cannot connect to EDGE. In other words, in an area where there is no 1900MHz 3G coverage, this process must be reversed to fall back to EDGE. As such, you may lose connection randomly and be completely unaware of it for hours, and I will mock you openly for attempting to blame me if you lose your job because you missed a call from your boss, lose your girlfriend because you stopped texting her, or lose your bacon because your remote bacon-protection app couldn't connect.
Remember, this is in the testing phase. It WILL get better over time and hopefully one day we won't even have to consider whether a phone supports 1700MHz... for now, though, report your findings below, preferably with location, signal strength/type, and down/up speed.
==PROCEDURE==​
Go to dialer and enter *#*#4636#*#*
In the menu that pops up, tap "Phone Information"
Scroll down to the menu labelled "Set preferred network type" (it should be the first one) - this will likely be set to WCDMA preferred
Change it to WCDMA only
Switch to your main Settings app, then navigate to "Mobile Networks" (under "More..." by your Wi-Fi and Bluetooth)
Tap "Network Operators" and wait for the search to complete
Tap T-Mobile if it appears in the list
Once the phone has acquired a signal, you can return the Network Mode setting to WCDMA Preferred. Your phone should now switch back and forth between EDGE and HSPA+ fairly reliably.
===My Results===​
At my home (approx. Colfax and Yosemite in Aurora, CO) I get 0-2 bars, mostly 3G but some H+ if I'm holding my phone and moving around, and 2-3 bars H+ if I set my phone down. Speedtest results range between 4 and 10 Mbps, with around 90ms ping. I've been keeping my phone set down with wireless tethering enabled, and it's been 100% usable thus far.
--Update--
Having used it daily for a few weeks, I'm pleased to report that there is moderate to good connectivity to at least 3G in most places. I still find myself on EDGE regularly, but I usually can get a WCDMA connection. Now, however, I'm annoyed because I exceeded 5GB data usage and am being throttled to below-EDGE speeds, which defeats the purpose of having 3G. >_<

what about AWS band ????/ its work

saqi4you said:
what about AWS band ????/ its work
Click to expand...
Click to collapse
Almost certainly not; see here.
If you have it working for some reason, go over there to tell everyone.

I'll test this later tonight. I'd be cool with 3G or H+ if it works. I have a T-Mob pay-by-the-day sim card that I'd like to use to tether my Nexus 7 to when I'm traveling (which is fairly rare).

I'm new to all this but how is this different from changing the APN settings?
Is this method better than changing APN settings?

This didn't work for me, Portsmouth, NH. It picked up the T-Mobile network in Network Operators but when I tried to select it it took forever and then said unable to connect, failed to register. Attempted a few times on a ucdlk3 stock based custom rom (Intergalactic II) and also on stock rooted.
Probably just not in a good location for this to work.
Sent from my Nexus 7 using xda premium

[Q] t mobile h+

Ive recently attained a captivate glide and unlocked it to use on t mobile. Like you would assume at first glance i had an edge connection. Although after messing around with it i realized by going to
Wireless and network > Mobile networks > Network operators >Default setup > Manual it gives me the option to choose to connect to att/ tmobile and when i chose tmobile and it registers on the network i get H+ speeds for a few minutes then it just defaults back to edge
is there a way i can keep my phone on H+ at all times because its capable

bump!

agchopz said:
Ive recently attained a captivate glide and unlocked it to use on t mobile. Like you would assume at first glance i had an edge connection. Although after messing around with it i realized by going to
Wireless and network > Mobile networks > Network operators >Default setup > Manual it gives me the option to choose to connect to att/ tmobile and when i chose tmobile and it registers on the network i get H+ speeds for a few minutes then it just defaults back to edge
is there a way i can keep my phone on H+ at all times because its capable
Click to expand...
Click to collapse
I have this problem too, but only into my house. Outdoor that´s right. I´ve tested with all modems, and I think the best for me is i927UCLH2.
Which rom, kernel and baseband do you use??

I´ve done some tests with my glide and my mother´s galaxy chat, in different places. In the street I have H+ and she H, but when we are into any house, under any roof, she still has H, and I only have E.
Does it happen to you?

shmemse when
mario_isp said:
I´ve done some tests with my glide and my mother´s galaxy chat, in different places. In the street I have H+ and she H, but when we are into any house, under any roof, she still has H, and I only have E.
Does it happen to you?
Click to expand...
Click to collapse
Doesn't this just sound like a basic signal issue? When the signal gets worse (indoor vs. outdoor) it will drop down to a lower signal.
Also, are you sure Tmo has fully rolled out the 1900mhz band in your area? They may not have complete coverage yet.

epsalmond said:
Doesn't this just sound like a basic signal issue? When the signal gets worse (indoor vs. outdoor) it will drop down to a lower signal.
Also, are you sure Tmo has fully rolled out the 1900mhz band in your area? They may not have complete coverage yet.
Click to expand...
Click to collapse
i'm sure that it is a phone or a software phone problem, cause i've put my sim card in my last phone (xperia pro) and it has H signal too
i've tested all rogers and att modems, and still have the problem..

Hi, I have a similar prob, I'm in the uk and need it to stay on H+, as it'll drop off to 2g in the house, I've always used miui roms in the past and they have the option to force 3g etc. The only way round this I could find is to use 'pimp my rom' which allows you to select which network you want manually, such as gsm, edge, wcdma etc. Download it, go to tools, device hidden menu, turn off radio, wait, turn radio back on, then quickly select from the drop down box what signal you want, I select wcdma only. If the radio does not come back on, put on flight mode then off again, and will work.. bit annoying but works..

That happen to me too, but not for t mobile, for a operator that use 1900mhz in my country.

[Q] D851 (T Mobile) on AT&T - Network Data Keeps Dropping

I just bought a T Mobile LG G3 (D851) for use on AT&T. The guy I bought it from got the unlock code from T Mobile and that is all squared away and unlocked. Things are basically working on AT&T, but data is not working reliably for me. It works fine for awhile, then it just stops working--the 4G/LTE logo in the status bar disappears and I have no connectivity. I can still make phone calls and send/receive SMS texts (though no MMS texts), and if a wifi network is around, that works too. Rebooting does not seem to correct it (though it does start working again eventually).
I don't know if it is just random, but it does seem to happen after I'm leaving somewhere with wifi (and that may not even be relevant--might be that's just when I notice it).
I have verified my APN settings (as well as tried other slightly different settings I've found around the web), but the data network still drops out. Yesterday, I discovered a technique that seems to reliably bring it back on after it has dropped out. If I change the Network Mode to anything else (ex: just GSM), then back out of the network options menu... then go back in and set Network Mode back to LTE (etc). Every time I have tried this, I get the 4G/LTE logo back in the status bar and my connectivity is back.
I know there is some difference in the LTE bands supported by AT&T and the T Mobile LG G3 (D851), but the phone supports band 17, which I'm told is the main LTE band used by AT&T. At this point, I think I'd be satisfied just to have consistent 4G (non-LTE) data.
Any idea what might be the issue? Or anything I can try out? I'm considering flashing a different rom to see if that helps, but wanted to exhaust other options first.
Thanks...

G4 H815 doesn't stick to LTE - apn okay, lp&mm stock kdz already flashed

Hello!
I have a big problem with my G4 (H815 version, Germany) beginning with the switch from CM13 to the (stock based) Genisys 3.2 ROM. I've tried to fix it for three days now but without success. It doesn't stick to LTE anymore like it should do and did before. After a reboot it does sometimes connect to LTE but after switching back from wifi or airplane mode it's showing the "no signal" icon. Then it takes some seconds until it reconnects to the mobile network but now just to 2G or 3G. From this point it's not willing to reconnect to LTE, even not through the manual RAT-selection. "Force LTE" using the hidden menu then results in no network connection. However, after restoring my EFS-partition-backup with TWRP (from a time when it was working perfectly) it's connecting to LTE directly after boot but only once and only until you toggle wifi or go offline - like described before. After the next reboot it will mostly connect to 3G and then maybe switch to LTE sometimes or not.
Of course I have checked, deleted and restored my APN multiple times, I have also recovered to a stock V20b and V10d .kdz using LG UP in refurbish mode. Unfortunately even on the fresh and untouched V10d install it shows the same strange behaviour. Restoring the CM13 backup (including EFS partition), which has worked perfectly before, shows the same network bug now.
My sim-card is still working perfectly in my other phones. It still connects and reconnects almost instantly to LTE in my old S4 in places where the G4 did the same but struggles now.
I have even tried the cdmatool which is used to unlock additional LTE bands. I didn't change anything but it does show all usual LTE-bands which are needed for my provider.
Does anyone have an idea what I could try next? I'm living in an area with much better LTE than 3G connection and paying for a quite expensive LTE contract so a working LTE is very important for me. If I don't get that to work again I would need to replace my just over one month old G4 :crying:
Many thanks in advance for your answers
f-rouz

Meanwhile I have also tried another simcard. Still no LTE

i have the exact same problem, well, almost. no unlocked bootloader, but when i first got the phone i root injected the system.img and flashed away, thought everything was fine. now it just doesn't reconnect to 4G. well, at home at least. on my S4 i get 4 out of 5 bars on 4G, with the G4 i get 2 or 3 bars out of 5 on 4G, so the signal isn't great but good enough. i live in hastings (a town) and went to brighton today (a city) where the signal is max 4G, and the device does pick it up. but as soon as i go through a 3G area to home, it doesn't reconnect. have tried flashing original system.img back, upgrading to MM 6.0 after factory reset (via LG bridge), then downgraded again to V10c via LGUP - factory reset before the downgrade, no joy, still the same.
when you say you have forced LTE in hidden menu, did you try this - enter 277634#*# in dialer and go to field test > modem settings > lte band selection and select the band for your operator, which can be found on 'wiki europe lte bands'. there were two bands for my provider (three UK) and band 3 was what i wanted. i can now switch to 4G but it's a pain having to this every time i come home ( i use my phone for home internet via tethering).
worst part is, having refrained from unlocking the bootloader to save the warranty, i phoned LG today to send it back as faulty and explained i could switch it to lte band 3 via the hidden menu and they told me my warranty was now invalid as had OPENED the hidden menu (they told me this after taking my imei). so if anyone reads this and phones LG for a repair, don't tell them you have accessed the hidden menu if you have done what i did.
think i'm just gonna sell the phone, make a palpable loss and buy another one, as i love the phone

Wow, I haven't thought that from LG. I feel like I've searched the whole internet already and nobody has a solution to this problem. I'm about to send my G4 back to Amazon (or sell it otherwise), hope the best and get myself a Oneplus Two because the G4 seems to be too *****y from the development standpoint. I've never had a situation like this with my previous Samsung phones since 2009. I will miss this camera though. And the NFC and the wireless and fast charging capability... the G4 is a nice phone nevertheless...
Edit: And yes, I have tried the "277634#*#" hidden menu, although it isn't accessible through this code on MM any more (you need a terminal command to start this).

Have you tried limiting it to 4G/2G in hidden menu? Mine also have a similar problem in Lollipop in that it is very aggressive in dropping to 3G. That worked for me. Phone doesn't drop to 2G much provided you have decent LTE coverage.
Now I'm on Marshmallow and not rooted, thus cannot do the same. Though it seems to be sticking to LTE a bit better than before.

I have tried that but it doesn't work. As I don't get any network connection wenn forcing LTE only, forcing LTE/2g results in 2g only.

My G4 still doesn't want to connect to LTE so I have ordered a S6 now... As I still have no idea what was causing this I just can't risk that happening again. It has been a short journey for my first LG and me and I really liked my G4 actually... Bye G4 community

you just needed to flash the stock modem, most likely

Unfortunately, it isn't that easy. That was of course the first thing I did (and not just one time)...

LTE connectivity issues, "3107" 3G network

Hi everyone,
My M9 has been having consistent issues with LTE connectivity. I'm rooted, s-off. The issue I'm having is that I regularly only connect to the 3G network, and my phone labels it simply as "3107". In the network list, I'm often connected to the Verizon Tracfone network, not the full vzwinternet network. If I manually switch these, it only lasts a short amount of time and LTE connectivity is weak. I've re-flashed a stock rom, same issue. New sim card even, same issue.
Any suggestions on how I can see exactly what bands are on/off and if my baseband firmware is out of date and/or broken - and if so - where I can get the latest version to try and fix it?
Thanks