Hey All,
I searched the web on and on and cant figure it out.
My provider Vodafone in holland provides me with 4G.
On some sites i read there is a minor update which activates the LTE option.
that update is for the I9505..
I cant find if its possible to unlock my LTE option.
i have the I9295. And throug kies or OTA is no update
I hope you can help me out guys.
Thaantje said:
Hey All,
I searched the web on and on and cant figure it out.
My provider Vodafone in holland provides me with 4G.
On some sites i read there is a minor update which activates the LTE option.
that update is for the I9505..
I cant find if its possible to unlock my LTE option.
i have the I9295. And throug kies or OTA is no update
I hope you can help me out guys.
Click to expand...
Click to collapse
I can't really help you but as far as I know LTE is already unlocked and working on all international S4 Actives. Mine certainly worked perfectly out of the box - although I turned it off promptly because I have ****ty 4G coverage where I live so it was nothing but a battery drain for me.
Are you sure you have a 4G sim card, and that you are in an area where 4G has coverage?
If you go in under settings > connections > more networks > mobile networks > network mode don't you have the LTE option at the top?
Cederic said:
I can't really help you but as far as I know LTE is already unlocked and working on all international S4 Actives. Mine certainly worked perfectly out of the box - although I turned it off promptly because I have ****ty 4G coverage where I live so it was nothing but a battery drain for me.
Are you sure you have a 4G sim card, and that you are in an area where 4G has coverage?
If you go in under settings > connections > more networks > mobile networks > network mode don't you have the LTE option at the top?
Click to expand...
Click to collapse
Im not 100% but i got the textmessage from my provider, so i recon they only send it to people who are able to use the 4G.
Yes, i am in a 4g coverage area
i dont have the LTE option at the top no. i have:
- wcdma/gsm
- only wcdma
- only gsm
Thaantje said:
Im not 100% but i got the textmessage from my provider, so i recon they only send it to people who are able to use the 4G.
Yes, i am in a 4g coverage area
i dont have the LTE option at the top no. i have:
- wcdma/gsm
- only wcdma
- only gsm
Click to expand...
Click to collapse
Well then I really have no idea - the only thing I can think of is that you might need to replace your sim card if your provider didn't already do so in advance of the 4G rollout. Hopefully someone with more information might step in here, but the international version is LTE capable out of the box. If you don't hear anything else I'd suggest to try and contact vodafone and get a clear answer from them first.
If you check the mobile networks in your area and don't see anything that supports LTE, you may just live in an area that doesn't have it yet (people get 4G and LTE somewhat mixed up - 4G is the overall identifier for a whole class of technologies with "4th generation cellular networks" basically while LTE is technically one of those technologies so, it should rightfully be classified as 4G in most respects.
Having said that, the only way I got my GS4A to function in LTE mode - meaning it actually shows LTE in the notification bar under the 4 with a small G and LTE underneath it - was to go into the service menu (*#*#4636#*#*) and change the preferred network type to either LTE only or LTE/GSM auto (PRL). Once I did that the radio would reset and connect and then it would be in proper LTE mode. Doing a speedtest with the Speedtest.net app shows LTE as the connection whereas with my standard setting which is WCDMA Preferred (T-Mobile AWS) it'll just show as "4G."
I've had no luck making alterations in the Settings/Mobile Networks section, I have to change it in the service menu to get LTE functional. I don't use it because here in Vegas where I live (specifically my home location) the LTE mode gets me about 1-2 bars of signal (about 8-12Mbps) whereas the WCDMA Preferred setting pulls in 5 bars rock solid and 25-35Mbps.
Can't do screenshots or I'd add them, I'm running the pre-release MI2 ROM presently and that aspect is borked.
br0adband said:
If you check the mobile networks in your area and don't see anything that supports LTE, you may just live in an area that doesn't have it yet (people get 4G and LTE somewhat mixed up - 4G is the overall identifier for a whole class of technologies with "4th generation cellular networks" basically while LTE is technically one of those technologies so, it should rightfully be classified as 4G in most respects.
Having said that, the only way I got my GS4A to function in LTE mode - meaning it actually shows LTE in the notification bar under the 4 with a small G and LTE underneath it - was to go into the service menu (*#*#4636#*#*) and change the preferred network type to either LTE only or LTE/GSM auto (PRL). Once I did that the radio would reset and connect and then it would be in proper LTE mode. Doing a speedtest with the Speedtest.net app shows LTE as the connection whereas with my standard setting which is WCDMA Preferred (T-Mobile AWS) it'll just show as "4G."
I've had no luck making alterations in the Settings/Mobile Networks section, I have to change it in the service menu to get LTE functional. I don't use it because here in Vegas where I live (specifically my home location) the LTE mode gets me about 1-2 bars of signal (about 8-12Mbps) whereas the WCDMA Preferred setting pulls in 5 bars rock solid and 25-35Mbps.
Can't do screenshots or I'd add them, I'm running the pre-release MI2 ROM presently and that aspect is borked.
Click to expand...
Click to collapse
I can check my area on the vodafone site. I live in a 4G network area 100%!
i guess my wcdma is sufficient then.. didnt experience speedboost tho..
br0adband said:
I've had no luck making alterations in the Settings/Mobile Networks section, I have to change it in the service menu to get LTE functional.
Click to expand...
Click to collapse
That would be because you're on the i537 from ATT, rather than the i9295 that this discussion is about. I checked google and vodafone holland does indeed use LTE on the right bands in its brand new rollout, so it isn't that - most likely it's his sim that needs replacing or it's just not activated on his account yet.
I have an unlocked Galaxy S4 active i9295 and I cannot get the 4G or the LTE working since I do not have even the option I only have WCDMA/GSM I travel around the world with this phone and now I am in Ireland on 3 and still I am getting H+ showing and not LTE or 4G. Is there a way to activate 4G or is there any special 4G sims ?
I would check your APN settings, seeing how you are unlocked, the proper APN may not be installed to match your Sim, check with your carrier, to make sure they are 4G and LTE capable and get their settings.
Sent Via Smoke Signals
Try ShowServiceMode. It should help to unlock LTE band. It worked for me here in Poland, because local career's LTE was locked by my Russian firmware. But using this program I can only switch between phone calls (GSM/3G) and LTE, they cannot work simultaneously.
Thank you guys. One major thing is that why I can even see the option in the settings? If anyone else has some information please help out.
Thanks
So i took out the Sim from the Iphone 6 im returning and popped it into this bad boy. Curious as to how you guys are setting up the phone so you get the correct LTE speeds. Im barely getting 9down whereas my gf's galaxy in the same room is getting 20+ down. wonder if i did anything wrong
It depends on location. I've seen consistent 50+ down and 20+ up with T-Mobile and default APN.
dew.man said:
It depends on location. I've seen consistent 50+ down and 20+ up with T-Mobile and default APN.
Click to expand...
Click to collapse
Nah something is def wrong. Phone is barely usable without wifi. What APN settings are you guys using for tmo?
fast.t-mobile.com it should also give you the settings automatically if you just press the "Internet settings" button.
ikon8 said:
fast.t-mobile.com it should also give you the settings automatically if you just press the "Internet settings" button.
Click to expand...
Click to collapse
Thats what i been running. Could it have something to do with the sim? Was i supposed to get a sim for an unlocked phone? Urrgh so frustrating
That's pretty slow, your gf has the tmo also? Pop her sim in your phone and compare. The sim shouldn't matter though.
ikon8 said:
That's pretty slow, your gf has the tmo also? Pop her sim in your phone and compare. The sim shouldn't matter though.
Click to expand...
Click to collapse
shes got a galaxy s4 so that wont work. however i still got the iphone 6 around. when i put the sim in that phone i get regular LTE speeds.
Oh, I just noticed in your speedtest result you're on H, not LTE. Under "preferred network mode" do you have "4G (preferred)" enabled? If you're in a border coverage area it could be that your phone is dropping you down to HSPA+ instead of staying on LTE.
For a test, go to the dialer and do *#*#4636#*#* then go to Phone Info and change it to LTE Only and test it to see if it stays on LTE and what kind of speeds you get, by default it's set to "LTE/GSM auto PRL" so if the LTE connection isn't strong enough it's going to drop you down to H+.
ikon8 said:
Oh, I just noticed in your speedtest result you're on H, not LTE. Under "preferred network mode" do you have "4G (preferred)" enabled? If you're in a border coverage area it could be that your phone is dropping you down to HSPA+ instead of staying on LTE.
For a test, go to the dialer and do *#*#4636#*#* then go to Phone Info and change it to LTE Only and test it to see if it stays on LTE and what kind of speeds you get, by default it's set to "LTE/GSM auto PRL" so if the LTE connection isn't strong enough it's going to drop you down to H+.
Click to expand...
Click to collapse
These Are my options under preffered:
wcdma only, gsm only, wcdma (preffered)/gsm and 4g(preffered)/wcdma/gsm. i dont see lte in the list
per your test, when I switch to LTE only in phone options the I lose all bars and signal totally craps out.
So when you switched to LTE Only, after a second or 2 you didn't get a 4G symbol above the signal bar? Do you ever see 4G? Mine switches to 4G within about 1 second of switching to LTE Only.
ikon8 said:
So when you switched to LTE Only, after a second or 2 you didn't get a 4G symbol above the signal bar? Do you ever see 4G? Mine switches to 4G within about 1 second of switching to LTE Only.
Click to expand...
Click to collapse
negative. just all bars gone and a big red x. you have this phone on t mobile also? did you do the us firmware update?
Yea, I'm using tmo. My phone is running 23.0.A.2.105
I got 2.93 maybe which one is 105??
I was worried during my first day of owning the phone because my Z1c showed LTE above the bars and now this Z3c shows 4G. I was worried that 4G != LTE.
I am having issues with the 4G on my Nexus 6.
I live in the UK and I am about 150 Yards from my nearest Tower. I am well within a 4G coverage area but I get no 4G connection.
I am using the Carrier Giffgaff a subsection on the O2 network.
I have a 4G sim with a 4G package so I know I should be recieving 4G. I am waiting for my carrier to get back to me on my issues.
I was just wondering if anyone could suggest anything that may help.
I have rebooted my phone multiple times.
I have cycled Data on / off multiple times
I have cycled through Airplane mode.
I've switched the network to 3G only and back again.
In phone dialer do this: *#*#4636#*#*
Then choose what you want to connect with.
what is 4G? what kind of signal are you talking about? both hspa+ and lte are considered "4G". 4G is just a term that data providers use, its not a real signal.
simms22 said:
what is 4G? what kind of signal are you talking about? both hspa+ and lte are considered "4G". 4G is just a term that data providers use, its not a real signal.
Click to expand...
Click to collapse
In the UK 4G is considered LTE but I am recieving neither HSPA+ or LTE
ColdEmbrace said:
In the UK 4G is considered LTE but I am recieving neither HSPA+ or LTE
Click to expand...
Click to collapse
if you dial *#*#4636#*#*, then press phone info, you can set your radio as lte only. after setting lte only(you wont get phone calls on lte only btw. it needs to be set to lte/gsm or lte/cdma/gsm to get calls as well). if you get no signal on lte only, then you either dont have lte in your area, or you need to talk to your provider.
simms22 said:
if you dial *#*#4636#*#*, then press phone info, you can set your radio as lte only. after setting lte only(you wont get phone calls on lte only btw. it needs to be set to lte/gsm or lte/cdma/gsm to get calls as well). if you get no signal on lte only, then you either dont have lte in your area, or you need to talk to your provider.
Click to expand...
Click to collapse
Thanks for the help, no such luck LTE only gives me no service at all. I'm definitely in a 4G area. Will have to wait for my providers response.
ColdEmbrace said:
Thanks for the help, no such luck LTE only gives me no service at all. I'm definitely in a 4G area. Will have to wait for my providers response.
Click to expand...
Click to collapse
do you have another device, with the same provider, and with lte, thats getting lte in your area?
simms22 said:
do you have another device, with the same provider, and with lte, thats getting lte in your area?
Click to expand...
Click to collapse
No such luck im afraid. But according to my provider pages there's a small percentage of customers 1 in 1000 with the inability to connect to 4g even when fully set up and standing directly next to the mast. Seems to be an ongoing issue for the last month. Maybe I fall in that category just need to wait till they respond.
ColdEmbrace said:
No such luck im afraid. But according to my provider pages there's a small percentage of customers 1 in 1000 with the inability to connect to 4g even when fully set up and standing directly next to the mast. Seems to be an ongoing issue for the last month. Maybe I fall in that category just need to wait till they respond.
Click to expand...
Click to collapse
Are you with o2 by any chance? I'm having the exact same problem. I'm in the UK as well and haven't been able to get LTE/4G at all since I put the sim in my Nexus 6. Could get LTE almost everywhere with my Note 4.
Ask your provider to give you a replacement sim or at least go and try one in a store that is in a 4G area. This will if nothing else rule that out.
Sent from my Nexus 6 using XDA Free mobile app
For a while now (I'm not sure exactly when it started, maybe a week ago or so) my Nexus 6 has only been showing me "3G" in the status bar. It used to show "H" most of the time.
Didn't think much about it at first, but now I was wondering because I had a Moto X (2014) before and that phone *always* showed H and practically never 3G.
So I opened the *#*#4636#*#* menu and checked under Phone Information, there it says "UMTS" under "Network type". I think it used to be "HSPA" under that item if I was connected via HSPA.
At first I thought maybe my carrier had some kind of network problem, so I did a speed test for the heck of it. The weird thing is, I'm getting speeds of 7 Mbit/s down and 1 Mbit/s up. These are HSPA speeds. So I must be connected via HSPA after all?!
It's not a problem per se since I get the speeds I want, but I'm still a little anxious something might be wrong with my Nexus 6.
Anyone know if they changed the behavior of the indicator in the status bar or something? Or is this related to some setting that I'm not aware of?
A friend of mine with a Nexus 5 on the same carrier as me is still getting the "H" in the status bar (albeit living a few hundred km away).
Nexus 6, completely stock and unrooted.
I have LTE deactivated by the way, because even though we do get LTE coverage here, my plan doesn't cover LTE speeds. If I activate LTE, the phone changes to the LTE network. 2G (EDGE) is also working and displayed correctly.
Are you on Lollipop or Marshmallow? Quick story: I only get HSPA at school and it used to say H/H+ when I was on Lollipop. After updating to 6.0 it says 3G now. If you're on Marshmallow I think it's 100% normal and nothing to worry about.
Face_Plant said:
Are you on Lollipop or Marshmallow? Quick story: I only get HSPA at school and it used to say H/H+ when I was on Lollipop. After updating to 6.0 it says 3G now. If you're on Marshmallow I think it's 100% normal and nothing to worry about.
Click to expand...
Click to collapse
I am on Marshmallow actually. Weird thing, though, is that my friend with his Nexus 5 on Marshmallow still sees H. Maybe they changed something just on the Nexus 6, but why would they? Plus on another forum someone said they still see "H" on their Nexus 6. I don't see it at all anymore.
Pyrazol said:
I am on Marshmallow actually. Weird thing, though, is that my friend with his Nexus 5 on Marshmallow still sees H. Maybe they changed something just on the Nexus 6, but why would they? Plus on another forum someone said they still see "H" on their Nexus 6. I don't see it at all anymore.
Click to expand...
Click to collapse
I still see H, but very rarely. Maybe 3G is the new H+? So it goes E, H, 3G, then LTE now instead of E, H, H+, LTE like it used to?
When it says H in the status bar, it will say HSPA in settings > about phone.
When it says 3G in status bar, it will say UMTS.
3G will download up to 7.2 Mbps.
HSPA+ will do 21 Mbps
DC-HSPA will do 42 (21 on each channel) though I don't think we support this..
---------- Post added at 07:11 PM ---------- Previous post was at 07:09 PM ----------
Face_Plant said:
I still see H, but very rarely. Maybe 3G is the new H+? So it goes E, H, 3G, then LTE now instead of E, H, H+, LTE like it used to?
Click to expand...
Click to collapse
goes: GPRS, E (edge), 3G (UMTS), H (HSPA), H+ (HSPA+), LTE / 4G
danarama said:
When it says H in the status bar, it will say HSPA in settings > about phone.
When it says 3G in status bar, it will say UMTS.
3G will download up to 7.2 Mbps.
HSPA+ will do 21 Mbps
DC-HSPA will do 42 (21 on each channel) though I don't think we support this..
---------- Post added at 07:11 PM ---------- Previous post was at 07:09 PM ----------
goes: GPRS, E (edge), 3G (UMTS), H (HSPA), H+ (HSPA+), LTE / 4G
Click to expand...
Click to collapse
I see. I thought they were just using a new symbol for HSPA/HSPA+ in Marshmallow. I never saw 3G in my status bar on Lollipop. It was always H/H+/LTE.
just read the title to your thread.. just so that you know, H, or hspa, is 3G.
and speeds of 7mb /1mb are very slow hspa speeds, but normal 3G speeds. on H, and on tmo, i can see speeds up to 21mbps. and on H+, i can see speeds up to about 42mbps.
I've noticed something similar. Almost like the signal bar and type is sticking. Putting it into airplane mode often switches it back to how it used to be.
I also find the signal bars seem to be sticking too. Where I normally get full signal it sometimes shows lower (and at multiple locations).
No idea why, only since marshmallow.
Face_Plant said:
I see. I thought they were just using a new symbol for HSPA/HSPA+ in Marshmallow. I never saw 3G in my status bar on Lollipop. It was always H/H+/LTE.
Click to expand...
Click to collapse
I sew 3G occasionally. It's rare because usually where there is 3G, there is HSPA.
simms22 said:
just read the title to your thread.. just so that you know, H, or hspa, is 3G.
and speeds of 7mb /1mb are very slow hspa speeds, but normal 3G speeds. on H, and on tmo, i can see speeds up to 21mbps. and on H+, i can see speeds up to about 42mbps.
Click to expand...
Click to collapse
Technically, HSPA is 3.5 G.. It's an evolution of 3G, but as per my previous post, they are indicated differently both in the status bar and about phone.
OP is not seeing HSPA of it shows UMTS in about phone.
danarama said:
When it says H in the status bar, it will say HSPA in settings > about phone.
When it says 3G in status bar, it will say UMTS.
Click to expand...
Click to collapse
Yup, thanks, that's what I thought it was.
simms22 said:
just read the title to your thread.. just so that you know, H, or hspa, is 3G.
Click to expand...
Click to collapse
I do know that. I'm aware of all the intricacies of these more or less arbitrary names. Though I thought non-HSPA 3G wouldn't give you more than 384 kbit/s down, while HSDPA (no +) would give you up to 7 Mbit/s. That's what wikipedia and quite a few other sources say anyway. But what Google or whatever manufacturer shows you as "3G" and "H" and "H+" could be something different entirely, so...
The question is more or less, what does stock Android mean when it says "3G" and "H" in the status bar. It used to and still seems to be 3G == UMTS and H == HSPA. So in essence, I'm wondering why my Nexus 6 is never showing me any HSPA anywhere anymore. Is it a software issue (i.e. Android not showing the correct value, or Android not making the hardware connect to HSPA), a hardware issue (broken Nexus 6) or a carrier issue. The latter seems unlikely, at least in a general sense, since my friend on the same carrier still sees "H" in the status bar.
This isn't about how fast the network is or should be, but rather just if I'm looking at a hardware fault that I should be concerned about, since it just changed all of a sudden.
Amos91 said:
I've noticed something similar. Almost like the signal bar and type is sticking. Putting it into airplane mode often switches it back to how it used to be.
I also find the signal bars seem to be sticking too. Where I normally get full signal it sometimes shows lower (and at multiple locations).
No idea why, only since marshmallow.
Click to expand...
Click to collapse
I've had that too. My signal indicator stuck at 0 bars indefinitely. Anywhere I moved it kept showing 0 bars, even at places that always have good reception. But I could still make calls and use data just fine. Airplane mode fixed that for me as well when I had it.
I've been through several reboots and Airplane mode switches so far though and HSPA (or rather the "H" in the status bar) isn't coming back for me.
Check your mobile data settings to make sure you're not limiting anything and check your apn too.. It's unlikely hardware.
Speed is useful. Your speeds are much too low to be HSPA so it's indicative that you really are connecting as 3G only.
Out of curiosity, for those that are seeing 3G appear at the top, you guys on T-Mobile? I started noticing this too as of yesterday. I work in a large commercial building where I can't get LTE yet (until at least T-Mobile flips the B12 switch) and typically I get HSPA(+). I thought it was coincidence that I started seeing 3G as of yesterday as there is some tower maintenance going on (at least that's what a T-Mobile RF engineer told me)
My phone is currently on 6.0 build MRA58K.
On a side note, has anybody else noticed their signal being worse since the 6.0 OTA? I'm getting at least -10dBm worse now vs my Nexus 7 LTE (running 5.1)
Mitalis said:
Out of curiosity, for those that are seeing 3G appear at the top, you guys on T-Mobile?
Click to expand...
Click to collapse
I'm actually on AT&T.
Mitalis said:
On a side note, has anybody else noticed their signal being worse since the 6.0 OTA?
Click to expand...
Click to collapse
I have also noticed a weaker signal and more time without signal (went from 0-2% on Lollipop to 9%+ according to the battery stats). I flashed the factory image (too impatient for OTA's). I haven't tried any of the older radios yet.
danarama said:
Check your mobile data settings to make sure you're not limiting anything and check your apn too.. It's unlikely hardware.
Speed is useful. Your speeds are much too low to be HSPA so it's indicative that you really are connecting as 3G only.
Click to expand...
Click to collapse
I did already check mobile data settings and switched everything around in there, but no change. APN settings too. I haven't changed anything in either of those places anyway so an issue with them seems unlikely to me.
In my case, speeds aren't really useful, because my carrier limits them softwarewise to the speeds I have (7 Mbit/s). So even if I turn on LTE (have it switched off normally) I only get 7 Mbit/s - but still the LTE signal indicator.
I doubt it's a carrier issue since my friend still sees the H, you doubt it's a phone issue, so that just leaves us with a software issue
Mitalis said:
I work in a large commercial building where I can't get LTE yet (until at least T-Mobile flips the B12 switch) and typically I get HSPA(+).
Click to expand...
Click to collapse
You might want to check with T-Mobile about band12 support for the Nexus6 on Marshmallow with the stock radio. There have been reports that T-Mobile had band12 support disabled on the Nexus6 unified Marshmallow build.
Maybe they already flipped the B12 switch, and that has left you with just 3g ?
Sent from my VS985 4G using Tapatalk
trent999 said:
You might want to check with T-Mobile about band12 support for the Nexus6 on Marshmallow with the stock radio. There have been reports that T-Mobile had band12 support disabled on the Nexus6 unified Marshmallow build.
Maybe they already flipped the B12 switch, and that has left you with just 3g ?
Sent from my VS985 4G using Tapatalk
Click to expand...
Click to collapse
Band 12 works on Marshmallow, I noticed it the other day when I was downtown in an area that had coverage, I'm just waiting on them to flip the switch in my area.
Mitalis said:
Band 12 works on Marshmallow, I noticed it the other day when I was downtown in an area that had coverage, I'm just waiting on them to flip the switch in my area.
Click to expand...
Click to collapse
What kind of SIM do you have band12 working on Marshmallow?
Band12 even just for data is for sure disabled under Marshmallow with a Project Fi SIM. Didn't use to be.
If band12 and T-Mobile VoLTE work with Marshmallow using a T-Mobile SIM, that is great news and I hope they will be able to get the 6p and 5x also to work on band12, and soon.
Project Fi, at least, is in a bit of a pickle over this issue, since they do not and will not use T-Mobile's proprietary VoLTE while on band12, and T-Mobile is refusing access to band12 without that certification.
Sent from my VS985 4G using Tapatalk
trent999 said:
What kind of SIM do you have band12 working on Marshmallow?
Band12 even just for data is for sure disabled under Marshmallow with a Project Fi SIM. Didn't use to be.
If band12 and T-Mobile VoLTE work with Marshmallow using a T-Mobile SIM, that is great news and I hope they will be able to get the 6p and 5x also to work on band12, and soon.
Project Fi, at least, is in a bit of a pickle over this issue, since they do not and will not use T-Mobile's proprietary VoLTE while on band12, and T-Mobile is refusing access to band12 without that certification.
Sent from my VS985 4G using Tapatalk
Click to expand...
Click to collapse
I'm using a T-Mobile sim. The Nexus 6 hardware was certified to work through T-Mobile, which I'm guessing why B12, VoLTE, & WiFi calling work on this phone.
I don't know what the case is with the Nexus 5x or 6p, as those are being sold through Google only, where as you could purchase the Nexus 6 through T-Mobile.
trent999 said:
Project Fi, at least, is in a bit of a pickle over this issue, since they do not and will not use T-Mobile's proprietary VoLTE while on band12, and T-Mobile is refusing access to band12 without that certification.
Click to expand...
Click to collapse
How do you know that? Are you privy to the MVNO agreement between T-Mobile and Project Fi? That is not the same thing as TMO's certification requirement for devices using a T-Mobile SIM.
All we know with any certainty is that Band 12 data connections used to work for Project Fi users under 5.1.1, but do not work for those running Marshmallow today. We don't know why. It could be that "T-Mobile is refusing access" contractually, as you claim. Or it could be a technical issue that broke something in the new radio.
We do know that T-Mobile is refusing access to band12 data unless the device also using T-Mobile VoLTE, because that has been said both by T-Mobile and acknowledged on the Project Fi support boards.
You are technically correct though that we do not know for sure if that is why Project Fi users no longer get band12 data access with Marshmallow.
We also don't know it that is why neither the N5x nor the 6p get band12, even with a T-Mobile SIM in, yet. That might be some certification issue, despite press reports about T-Mobile requiring it's removal.
I am glad it is working on your N6 with your T-Mobile SIM in place. I hope it will work on mine with my T-Mobile prepaid SIM, too.
Some Project Fi users are claiming that as of Marshmallow, Fi should no longer claim that Fi users have the exact same coverage on the T-Mobile network as T-Mobile customers, since they don't any longer.
Sent from my VS985 4G using Tapatalk