yashsingh1/xdaforums huggingface dataset:
[Nexus 6P Q&A, Help & Troubleshooting] landale:
VoLTE is required for T-Mobile to approve the enabling of Band 12 but having it active doesn't mean it's active yet which appears to be the case here. VoLTE works but I am guessing there is a wait for T-Mobile to certify the device. Project Fi can use it now since Google is an MVNO and likely decided they can always switch to Sprint if a user is on Band 12 and lacks the ability to call.
[Nexus 6P Q&A, Help & Troubleshooting] mgorman:
I only get band 4. I know I can get band 12 because my n6 got it. I do get HD calling which I assume is volte. And I do use WiFi calling
[Nexus 6P Q&A, Help & Troubleshooting] joedajoester:
My phone doesn't want to enable WiFi calling. If it does decide to turn on, it has issues sending SMS, they fail. I did manage to fix all the issues by reseating my sim card, however the issues returned and wifi calling disconnected and hasn't come back since. This is really frustrating. I'm on MDB08K
[Nexus 6P Q&A, Help & Troubleshooting] easyc:
FWIW, I'm currently on the phone with Google Tech Support. I don't get band 12 on either a T-Mo sim or Fi sim on my 6P. I, too, updated to MDB08K right out of the box. I believe I read on Reddit that someone dropped band 12 support after taking the update.

I tested this alongside my Galaxy S6, and that gets great band 12 reception. I might have Google send me a new device and refuse the update.
[Nexus 6P Q&A, Help & Troubleshooting] frigidazzi:
Wouldn't it be easier to flash factory image for that version to test?
[Nexus 6P Q&A, Help & Troubleshooting] easyc:
And run the risk of not being able to return the phone? I might just break down and get a Note 5. I'm not sure I have the patience to wait for Google to fix it. Originally it was reported as "by ship date". Now, I'm reading "a couple months". The Note 5 might be the better option at this point.
[Nexus 6P Q&A, Help & Troubleshooting] Banggugyangu:
Flashing a factory image should never void a warranty as you are putting the exact software that comes from the factory. If you Bork during the flash, as long as your bootloader is fine, there's nothing to worry about.

If you're willing to go with a different phone due to having to wait a couple months for more penetration of your cell signal, then I question your original decision of choosing a nexus device. I am personally done with non nexus devices, myself... I am sick of locked bootloaders (up until this week I was verizon), slow updates, and having support come from anyone other than G-Money.
[Nexus 6P Q&A, Help & Troubleshooting] papi92:
Volte is enabled on lastest update but not band 12. Band 12 is not activated on any version for the 6p. Now Fi does get band 12 bc Fi does not use volte. Fi will never use lte and as such will default down to HSPA+ bands for calls. Fi will get volte once they get it working on band 12.
[Nexus 6P Q&A, Help & Troubleshooting] SuperTongue:
http://xdaforums.com/nexus-5x/help/t-mobile-band-12-access-project-fi-t3237216

Has anyone else seen that? Looks like 5X owners were able to get Band 12 working on T-Mobile proper by flashing the radio from a previous version. Thoughts for us 6P owners?

NOTE: I got Band 12 working on the 6P! YOU MUST HAVE THE BOOTLOADER UNLOCKED OR UNLOCK IT PRIOR TO DOING THIS! Also, I am not liable for anything by you following these instructions. Just trying to help others out. Please note that you accept the risk of potentially being unable to call 911 if your phone is connected to Band 12 using this method! Instructions are as follows:

Download the MDA89D Factory Image

Open it (I used 7Zip) and extract radio-angler-angler-01.29.img

Copy this to the platform-tools directory on your computer and rename to radio-old.img (If you're unsure of how to do this, you probably shouldn't be fooling around with this stuff anyway. But if you want to, look up unlocking your Nexus 6P and that should steer you on the right path)

Power down and reboot into fastboot (Power + Volume Up + Volume Down)

Connect your phone to your PC

Run the command "fastboot flash radio radio-old.img"

Reboot

Not too difficult. This should just work without any problems, but - again - you are doing this at your own risk.

EDIT:

I just downloaded the MDA89D factory image and flashed the radio by itself. Will report back shortly.

EDIT2:

The device booted fine with the old radio image and the newest firmware, so we're good there. Waiting on the device restore as I had to wipe (since I was dumb when I got the device). Will report back once I get LTE Discovery installed.

EDIT3:

After a quick test with LTE Discovery, it looks like that worked in enabling Band 12! I ran downstairs where I could only get HSPA+ before and Band 12 with our Note 5 / G4 currently. Here's a shot of LTE Discovery:
[Nexus 6P Q&A, Help & Troubleshooting] jsho31:
[MENTION=5018962]SuperTongue[/MENTION]

Thanks, for this. I have a 5X and it worked and also worked on the 6P now.
[Nexus 6P Q&A, Help & Troubleshooting] SuperTongue:
I just did the basic "fastboot flash radio radio-name.img" and it worked fine.

I doubt it means anything, but I flashed the radio immediately after unlocking (but before it performs the wipe).
[Nexus 6P Q&A, Help & Troubleshooting] jsho31:
Edited my post. Lol. Realized what I did wrong.
[Nexus 6P Q&A, Help & Troubleshooting] SuperTongue:
Did you happen to use the 5X radio by chance? ;)

Glad to see it's working for others with the 6P, though!
[Nexus 6P Q&A, Help & Troubleshooting] jsho31:
lol nah, the folder i was running the commands from didnt have the fastboot/adb stuff in it. Not using my own computer at the moment. :eek::eek:
[Nexus 6P Q&A, Help & Troubleshooting] wizardfingers:
Can I flash this over MBD08K? Why is it not in the MBD08K radio?
[Nexus 6P Q&A, Help & Troubleshooting] SuperTongue:
Yes - you just need to use the MDA89D radio image. I flashed it over K and it worked fine.
[Nexus 6P Q&A, Help & Troubleshooting] <blank>:
Does VoLTE still work with the older radio?
[Nexus 6P Q&A, Help & Troubleshooting] papi92:
I'll be flashing it tonight. Very excited
[Nexus 6P Q&A, Help & Troubleshooting] NCguy:
Does flashing a radio image stop OTAs like flashing system blocks it?
[Nexus 6P Q&A, Help & Troubleshooting] wizardfingers:
Just flashed and I LTE Discovery showed band 12 awesome! So renaming the img to radio-old.img is necessary because when I flashed it with just the default name and I restarted it just showed "No Sim" Thanks.

Is there a way I can force my phone to stay on band 12...

BTW I'm on Project Fi
[Nexus 6P Q&A, Help & Troubleshooting] papi92:
You can not force a band. And yes this will screw up OTAs but you can always flash fastboot files to fix it
[Nexus 6P Q&A, Help & Troubleshooting] dcdttu:
I think Project Fi gets Band 12 access already. It's just T-Mobile subscribers that don't yet. Also, a guy on Reddit activated his N6P without internet so it skipped the update that likely disabled Band 12. He is reporting Band 12 as well.
[Nexus 6P Q&A, Help & Troubleshooting] SuperTongue:
I tried calling an 800 number and it stayed on LTE (band 12) when I made the call. Not sure if it makes a difference, but I use Google Voice to make all calls.

Can also confirm that Band 12 is definitely working as I'm now in a building where I could only get B12 or 2G. :good:
[Nexus 6P Q&A, Help & Troubleshooting] lemmyslender:
Flashed the old radio, and it appears to work.

In my office on Band 4 prior, showed only about 1/2 or 3/4 bars. After flashing the old radio, LTE Discovery shows B12 (previously showed B4), and now showing full bars. However, at text just kicked it back over to B4. I'll see how it works at home.
[Nexus 6P Q&A, Help & Troubleshooting] charlie460:
Yep, Band 12 is working for me after flashing the old radio as well. Thanks a lot for this. Was already annoyed by not having usable coverage in areas I had coverage before on my old phone.
[Nexus 6P Q&A, Help & Troubleshooting] JVaracalli:
download the t mobile app then verfiy your home location for e911 then ur wifi calling will work i had the same issue
[Nexus 6P Q&A, Help & Troubleshooting] sharpehenry:
I'm on T-Mobile and when I make calls my radio stays LTE, doesn't this prove that it is working on T-Mobile VoLTE? Or am I misunderstanding.
[Nexus 6P Q&A, Help & Troubleshooting] SuperTongue:
As far as I'm aware, that should prove VoLTE but not sure if that's the case. I made a call earlier on Band 12 and it went through without dropping down to 2G, so I imagine everything is working.
[Nexus 6P Q&A, Help & Troubleshooting] NCguy:
Yes, I think it does. But it does VoLTE on bands 2, 4, and 12. So if you're wondering if it's bsnd 12 VoLTE maybe not. You need an app like LTE discovery to see the band.
[Nexus 6P Q&A, Help & Troubleshooting] SuperTongue:
I made a call in a spot where I can only get Band 12 and the call went through fine and never dropped to 2G (which it would have done if VoLTE wasn't enabled). So I imagine VoLTE and Band 12 are working, T-Mobile is just taking their time to certify it.
[Nexus 6P Q&A, Help & Troubleshooting] NCguy:
You should install LTE discovery to confirm
[Nexus 6P Q&A, Help & Troubleshooting] SuperTongue:
I checked earlier when I made the call and it was on Band 12. I checked now and somehow it's magically displaying Band 4 which I've never been able to get down here before.

I'll try to force it down to Band 12, make the call, and see what happens.

EDIT:

Is it possible LTE Discovery is displaying the band incorrectly? Last week, before I flashed the old radio, I was never able to get LTE where I'm sitting. Now that I have the old radio flashed, I can get LTE again. It displayed as Band 12 this morning, but is showing Band 4 right now (despite there being almost no way it's actually Band 4).

Thoughts?
[Nexus 6P Q&A, Help & Troubleshooting] JVaracalli:
can some one make a video walk through for the installation process for this radio flashing process iv done my fair share of flashing phones but iv never edited a file before flashing it ie renaming so it would be helpful to me and probablymany others to make a video walk through t

---------- Post added at 06:17 PM ---------- Previous post was at 06:14 PM ----------

also for the people wondering about volte working or not you can type in *#*#4636#*#* this into your phone dialer and hit phone status in the menu it will give u an option to only use lte and no other radios so by doing this and making a phone call after that will give you the absolute answer
[Nexus 6P Q&A, Help & Troubleshooting] notfaded1:
idk about anyone else but I'm a little peaved that Google felt it necessary to update us out of using band 12! WTHeck Google! @#$%^&(* Seems lame that originaly pre update radio works but new one doesn't. I thought the original word was that google was rushing to get phones updated before they shipped so it WOULD work! Well now it's pretty apparent that the opposite is true!

One thing I will say about Tmobile... I took my old nexus 5 sim into store and said I needed a nano now... the store guy just got out a new nano and programmed it for my number after he pulled it up. Gave it to me with the two adapters for bigger sim phones and said you're all set! Nice! NO charge. Also he didn't even want the sim back from Nexus 5! Nice service TMobile rocks. Now google how about turning our band 12 back on for God's sake!
[Nexus 6P Q&A, Help & Troubleshooting] SuperTongue:
The additional steps for flashing aren't too bad. You just have to download the factory image, open it like a ZIP file, grab the radio image, then flash it. You technically shouldn't have to rename anything, but it just makes it a little easier when having to type out the flash radio radio-name.img command.
[Nexus 6P Q&A, Help & Troubleshooting] mgorman:
band 12 does not work with stock radio. VolTE does work using band 4 as I get the little HD icon when I make calls. I know band 12 isn't enabled because my N6 would get band 12 when I was in bed. My 6P only gets band 4 in the same exact spot. The only way to get band 12 currently is to flash that other radio that's circulating. If you aren't unlocked, then you will need to wait until TMO makes it official.
[Nexus 6P Q&A, Help & Troubleshooting] SuperTongue:
Yup, that's exactly what I wrote up in my post at http://xdaforums.com/showpost.php?p=63600159&postcount=24
[Nexus 6P Q&A, Help & Troubleshooting] lemmyslender:
Seems to be working, but I do bounce between B4 and B12, even though I get better signal on B12.

Send like the 6P gets better reception than my N5 anyway.
[Nexus 6P Q&A, Help & Troubleshooting] papi92:
The 6p has CA on band 4+12/12+4 even tho Google did not list it

---------- Post added at 02:32 AM ---------- Previous post was at 02:31 AM ----------

That explains why lte discovery keeps changing bands.
[Nexus 6P Q&A, Help & Troubleshooting] obsanity:
As far as I understand the band 12 VoLTE requirement is forced onto T-Mobile by our wonderful FCC. Because you can only get data on band 12 and would not be able to make an emergency 911 call, they chose to disable band 12 until VoLTE is implemented.

Thanks, FCC... Now if someone is buried alive with the N6p or any other phone with band 12 disabled in this fashion they'll never be able to send a message through Hangouts, Facebook, Snapchat, Skype etc to call for help.

FCC fail.
[Nexus 6P Q&A, Help & Troubleshooting] norwoodesteel:
are you sure, support said no
[Nexus 6P Q&A, Help & Troubleshooting] treIII:
Delete

Sent from my Nexus 6P using Xparent Blue Tapatalk 2
[Nexus 6P Q&A, Help & Troubleshooting] treIII:
In the general section the radio is available without downloading the factory image. It's in the index thread under radios. The thread is by Heisenberg. Thanks

Sent from my Nexus 6P using Xparent Blue Tapatalk 2

---------- Post added at 03:54 AM ---------- Previous post was at 03:47 AM ----------

What is CA? And thanks

Sent from my Nexus 6P using Xparent Blue Tapatalk 2
[Nexus 6P Q&A, Help & Troubleshooting] charlie460:
Carrier aggregation. It allows the phone to combine available bandwidth from two different LTE bands
[Nexus 6P Q&A, Help & Troubleshooting] cbowens:
Source?
[Nexus 6P Q&A, Help & Troubleshooting] charlie460:
Band 12+4 carrier aggregation seems to be working for me as well. I only get about 4-5 Mbps over Band 12 *only* with other devices but with the 6P I see over 20+ Mbps while LTE Discovery shows that I am connected to Band 12, so I'm assuming CA with Band 4 is working.
[Nexus 6P Q&A, Help & Troubleshooting] km8j:
Do we know if there were any negatives to this radio? Meaning any sort of bugs that were resolved in the new radio?

Doesn't unlocking the bootloader have negative impacts with encryption, etc.?
[Nexus 6P Q&A, Help & Troubleshooting] treIII:
Yeah. My speeds have doubled also. Definitely CA. And I'm liking it. Reception is excellent.

Sent from my Nexus 6P using Xparent Blue Tapatalk 2
[Nexus 6P Q&A, Help & Troubleshooting] boxcar8028:
LMAO:good::good::good:
[Nexus 6P Q&A, Help & Troubleshooting] cammykool:
can anyone post the individual radio image?
[Nexus 6P Q&A, Help & Troubleshooting] tom1226:
Sure, here you go! https://mega.nz/#!2IxyBRST and the key is !yueCFPQ0Ffrh4pTGG9BO2n5EyL224XUD77XcsC2kQog
[Nexus 6P Q&A, Help & Troubleshooting] cammykool:
Cool!
[Nexus 6P Q&A, Help & Troubleshooting] easyc:
So, I've been doing some dinking around. For those of us that don't want to blow the hardware fuse by unlocking the bootloader, there isn't really an option once you've updated until Google fixes the issue.

However, I can confirm that band 12 doesn't work on either Fi or T-Mobile sims on the MDB08K update. It's not a limitation of the sim either. I tossed my Fi sim into my T-Mobile Galaxy S6, and it works fully, (obviously only on T-Mobile towers, though). I get full band 12 on the Fi sim in the Galaxy S6. So it appears to definitely be the radio update in MDB08K.

On a side note, I've been less than pleased with Googles handling of this situation. I filed for a return, and they are treating it as a "Buyer's Remorse" return, subject to a short list of refund deductions. The customer service rep I've been dealing with has been rather deceptive in their approach to justifying that, claiming the technician I spoke with informed me that a fix was coming (they did not) and soon (no timeline given).
[Nexus 6P Q&A, Help & Troubleshooting] lp1527:
I am on Band 12 on new 6p that arrived yesterday. No mods, regular tmobile (not Fi). View attachment 3530626
[Nexus 6P Q&A, Help & Troubleshooting] mgorman:
What build are you running? Can you screen shot it?
[Nexus 6P Q&A, Help & Troubleshooting] lp1527:
I'm bouncing between Band 4 and 12 right now based on iffy but not terrible reception where I am...
[Nexus 6P Q&A, Help & Troubleshooting] NCguy:
There is a fuse but I think they are finding that dev activities like unlocking the bootloader wont blow it. You should search out the most recent findings if you're interested. The early reports were mostly speculation.
[Nexus 6P Q&A, Help & Troubleshooting] five40:
Angler Radio.img

FYI the radio image has been extracted and attached to this post.

So you don't have to download the entire factory image.

Nexus 6P MDA89D Radio

You still need to rename it to "radio-old.img" before flashing via fastboot
[Nexus 6P Q&A, Help & Troubleshooting] wifiguru:
+1. My Nexus 6P came with MDA89D today, has band 12 with a T-Mobile SIM.
[Nexus 6P Q&A, Help & Troubleshooting] kolyan:
VoLTE too?
[Nexus 6P Q&A, Help & Troubleshooting] obsanity:
For those of you with new out of the box phones, if you reject the update you'll have band 12 without flashing anything. But as soon as you update you'll loose it.
[Nexus 6P Q&A, Help & Troubleshooting] wifiguru:
Yep. VoLTE too.

I've made a few test calls and stay on LTE.
[Nexus 6P Q&A, Help & Troubleshooting] mgorman:
I've noticed that while connected to WiFi calling, I don't get text messages. As soon as I get cellular signal, my texts come though. Didn't have this problem with my n6. Maybe it's the lack of band 12 and the signal isn't reaching me inside work. But I thought WiFi calling allows you to send and receive texts
[Nexus 6P Q&A, Help & Troubleshooting] NCguy:
I'm on wifi calling right now and I just sent and received a text message
[Nexus 6P Q&A, Help & Troubleshooting] mgorman:
Maybe it's my crappy WiFi at work then
[Nexus 6P Q&A, Help & Troubleshooting] aborrelli:
I've noticed this exact issue too since I got the phone last week! I can't send text messages when I am on wifi. I can send text messages via google voice but not my carrier number. As soon as I get turn wifi off text messaging works. Seems to be an issue with wifi calling causing the issue. Very annoying (oh and this same issue happens no matter what wifi I'm on).
[Nexus 6P Q&A, Help & Troubleshooting] NCguy:
I just tried it again and it went right through. I believe you guys are having issues and I'll help you zero in if I can. Could it be APN related?
[Nexus 6P Q&A, Help & Troubleshooting] wifiguru:
You guys may need to enable IPV4 + IPV6 in the APN, and also select the fast.t-mobile.com APN.

I did this, rebooted, and have no issues with or without WiFi Calling/texting.
[Nexus 6P Q&A, Help & Troubleshooting] mgorman:
Seems to be working now after doing this. Thanks
[Nexus 6P Q&A, Help & Troubleshooting] kolyan:
Fi network is super weird, there are people that connect to B12 but can't used data, there are people that claim they have B12 and VoLTE and end up being wrong etc.

Even Project Fi reps have no clue if Fi supports Band 12. B12 was killed for most people on N6 with Android M update because of some issues with T-Mobile agreements or something.
[Nexus 6P Q&A, Help & Troubleshooting] papi92:
The issue is that if you get band 12 and no other band you can't make calls to 911. Fi is working on it but until Sprint supports VoLTE they are SOL
[Nexus 6P Q&A, Help & Troubleshooting] kolyan:
Fi has been ignoring everyone for the past month regarding b12 issue. They never said they are working on it
[Nexus 6P Q&A, Help & Troubleshooting] bitpushr:
Yea! :p
[Nexus 6P Q&A, Help & Troubleshooting] jcsww:
I was hoping this would work for me but no luck. )= Even with WiFi Calling enabled, connected to WiFi, it doesn't send or receive calls or texts with WiFi Calling enabled for me.
[Nexus 6P Q&A, Help & Troubleshooting] txaggies07:
I keep losing data after leaving a wifi connection. This happens almost every time I leave a place I have wifi. My T-Mobile LTE doesnt connect at all until I cycle Airplane mode. Any ideas?
[Nexus 6P Q&A, Help & Troubleshooting] NCguy:
Have you set your APN? Mine was flakey with the stock default setting.
[Nexus 6P Q&A, Help & Troubleshooting] txaggies07:
Yep. It is exactly same as my Nexus 6 and Moto X Pure. I went ahead and updated to the latest OTA and haven't had an issue since. I will see if that holds.
[Nexus 6P Q&A, Help & Troubleshooting] NCguy:
You may have lost your band 12 with that OTA. May have to flash the older radio.
[Nexus 6P Q&A, Help & Troubleshooting] txaggies07:
Yep. Flashed the radio. Everything appears to be working well. I should know tomorrow first time I leave the house.
[Nexus 6P Q&A, Help & Troubleshooting] vulcZ:
Interesting. Going to try this when I leave work tonight. My commute home has a large area with Band 12 support. I tried it late last week when I was still on build MDA89D and it was working fine. Now that I've upgraded to build MDB08L I will be trying it again. Going to be really disappointed if I lost Band 12 connectivity. Had a strange feeling that OTA might break something too, but I'm a big sucker for OTAs :)
[Nexus 6P Q&A, Help & Troubleshooting] jcsww:
I never got WiFi Calling fully working on the 6P. I had issues sending texts that have yet to be resolved. I tried my Nexus 6 on Marshmellow with the same issue. I rolled the Nexus 6 back to LYZ28N and everything seems to work with the exception of MMS over WiFi. Oddly enough, I can toss the SIM in my Lumia 635 and WiFi Calling, texting over WiFi, and MMS over WiFi work perfectly!

For those with WiFi Calling working on the 6P. What version are you running, as I was running the latest factory image but using MDB08M with the radio from MDA89D.
[Nexus 6P Q&A, Help & Troubleshooting] NCguy:
I'm running MDB08L. Wifi calling is working but today after the update I noticed the handoff from wifi to cell wasn't as smooth as before the update. It tried to hang on to wifi with zero bars.
[Nexus 6P Q&A, Help & Troubleshooting] jcsww:
Are you getting your updates from T-Mobile over the air or sideloading them?
[Nexus 6P Q&A, Help & Troubleshooting] NCguy:
OTA. I haven't rooted yet. They are actually from google.
[Nexus 6P Q&A, Help & Troubleshooting] jcsww:
Okay. That makes me wonder if rooting is the issue with Marshmellow.
[Nexus 6P Q&A, Help & Troubleshooting] vulcZ:
Just wanted to confirm my findings. MDB08LL does in fact remove Band 12 compatible for me also. Disappointing.

---------- Post added at 07:20 PM ---------- Previous post was at 07:19 PM ----------

Noticed this today also after updating to MDB08L. This sucks lol.
[Nexus 6P Q&A, Help & Troubleshooting] sirxdroid:
Anyone having problems with SMS while on WiFi calling? It seems to just sit there "Sending ..." It eventually works but I think it happens when I get a bit of cell signal. SMS should go over wifi too if wifi calling is enabled.
[Nexus 6P Q&A, Help & Troubleshooting] ImDonly1:
I had WiFi calling enabled and it would never work (at home or work where I know the internet is fast enough). I could never get it to say "T-mobile WiFi calling" on the quick settings pulldown. So my SMS would stall on sending for a while until they finally sent.

I just ended up turning WiFi calling off. Kind of disappointing.

Also none of my calls go over LTE. They all drop to 3G. I flashed the old radio that is supposed to enable B12/VoLTE and am in the Chicago market so it should be working?
[Nexus 6P Q&A, Help & Troubleshooting] sirxdroid:
WiFi calling works for me, just problems with SMS. Why do you think it should say "wifi calling" in the pulldown? Enable WiFi calling, go to Settings > About phone > Status > SIM status. Do you see IWLAN for cellular network type? If you do, wifi calling is enabled and should work.
[Nexus 6P Q&A, Help & Troubleshooting] NCguy:
Yes, I am experiencing it exactly as you describe.