Will the Nexus 5 support VoLTE? - Nexus 5 Q&A, Help & Troubleshooting

Will the Nexus 5 support VoLTE? - Nexus 5 Q&A, Help & Troubleshooting

So will the Nexus 5 support VoLTE?
AT&T has said VoLTE starts deployment by the end of this year. Does anyone think the Nexus 5 will work on AT&T's VoLTE?
This thread doesn't have to be about speculation. This is XDA and I expect more technically from this forum. Let's think about this systematically. What is required for a phone to work on VoLTE? Is the LTE hardware enough? Probably not. I think we can all agree that the software has to support it. I've read that the LG Connect 4G on MetroPCS supports VoLTE since they have already deployed VoLTE and it is supported using that phone. So that means Android has had VoLTE since Android 2.3 Gingerbread. Was that custom software for the LG Connect or is there still code in Android supporting VoLTE? Is anyone knowledgeable to look at Android 4.3 source files to see evidence of VoLTE living there, in comparison to the Android source in the LG Connect? Maybe there are system files in Android that have VoLTE in their name. That would be a good clue.
Was there anything in the LG Connect's FCC documentation that specified VoLTE testing or specifications? Is this needed for VoLTE? Or is LTE testing alone enough since it is all the same from a physical frequency perspective?
I brought this topic up in another forum and I got some good responses. I just want to take it to the next level here with all the gear heads and XDA wizardry that lives here.
Sent from my Nexus 10 using Tapatalk 4

galfert said:
So will the Nexus 5 support VoLTE?
AT&T has said VoLTE starts deployment by the end of this year. Does anyone think the Nexus 5 will work on AT&T's VoLTE?
This thread doesn't have to be about speculation. This is XDA and I expect more technically from this forum. Let's think about this systematically. What is required for a phone to work on VoLTE? Is the LTE hardware enough? Probably not. I think we can all agree that the software has to support it. I've read that the LG Connect 4G on MetroPCS supports VoLTE since they have already deployed VoLTE and it is supported using that phone. So that means Android has had VoLTE since Android 2.3 Gingerbread. Was that custom software for the LG Connect or is there still code in Android supporting VoLTE? Is anyone knowledgeable to look at Android 4.3 source files to see evidence of VoLTE living there, in comparison to the Android source in the LG Connect? Maybe there are system files in Android that have VoLTE in their name. That would be a good clue.
Was there anything in the LG Connect's FCC documentation that specified VoLTE testing or specifications? Is this needed for VoLTE? Or is LTE testing alone enough since it is all the same from a physical frequency perspective?
I brought this topic up in another forum and I got some good responses. I just want to take it to the next level here with all the gear heads and XDA wizardry that lives here.
Sent from my Nexus 10 using Tapatalk 4
Click to expand...
Click to collapse
i love your inquiry!
as we all know, tmobile's launching VOlte in seattle, via s/w upgrade to various phones, but why that way?
wouldn't it had been easier via an updated volte capable sim card with the needed provisioning?
what governs any phone's baseband code on certain networks; is it HARD coded, or SOFT coded, to change on the fly, depending on the network? -
iPhone can support VoLTE
that link also addresses how volte is implemented on tmobile's network..
or if one prefer - How it works: Voice over LTE (VoLTE)
one thing for sure, qualcomm & erricsson trialed volte on an earlier snapdragon chipset (Qualcomm's Snapdragon S4 MSM-8960)
the nexus 5's snapdrag, is a newer **Qualcomm MSM8974 snapdragon 800** .. i would doubt it DOESN'T
support volte, why add the feature to an older chipset, & not include it by default in a newer.. -
Qualcomm's Snapdragon almost ready for Voice over LTE (VoLTE) (February 2, 2012)
~edit~
i'm so glad i'm not mentally lazy (that's why i use linux dammit) the nexus 5 CAN DO VOLTE! -
Doug M.
Chief Operating Officer (COO) and Chief Sales & Marketing Officer (CSMO) at D2 Technologies, Inc.
We (www.d2tech.com) are trying to break the "chicken/egg" cycle by providing a commercial-ready reference implementation for native IR.92 VoLTE, IR.94 and RCS 5.1 / joyn for mobile devices. At MWC, we demo'd it on a Nexus 5, Huawei Ascend G716-L070, Nvidia’s Tegra 4i reference platform and an Intel® Atom™ based commercial handset. We're also providing several LTE modem IC vendors with an embedded IR.92 VoLTE solution that has APIs in the LTE modem IC to the mobile AP that allow the RCS/IR.94/WiFi calling capabilities embedded in the mobile OS to leverage the IMS registration and SIP signaling stack, and DSP voice engine that now reside in the modem IC. This makes it very easy for device OEMs to provide native RCS and/or VoLTE and IR.94 video calling.
from - http://www.linkedin.com/groups/China-Set-Lead-RCS-Integration-1890406.S.5849549644362706944
the nexus 5 can do volte on china mobile now, from china mobile's volte white paper - http://www.lte-tdd.org/upload/accessory/20138/20138271114319913691.pdf
3.4 Terminal Aspects
3.4.1 Multi-Mode and Multi-band
To meet the requirements for domestic frequency access and international roaming,
five radio modes including FDD LTE, TD-LTE, TD-SCDMA, WCDMA, GSM
should be supported by China Mobile TD-LTE terminals, which are divided into the
basic type and the enhanced type: the basic type terminal should support 5 modes and
10 bands, the enhanced type terminal should support 5 modes and 12 bands.
Furthermore, terminals with other multi-mode and multi-band capabilities can be
introduced to meet the market needs.
Supporting the Band41（2496-2690MHz）is mandatory for TD-LTE terminals in
2014. If the terminal support Band 41 without Band 38, it must comply with the
3GPP TS36.331 R8.H.0 and later versions, while for the terminal with both
Band41 and Band38, it is not needed to support the 3GPP TS36.331 R8.H.0
version.

qualcomm msm8974ab bring up kernel log ( that the nexus 5 has)
<6>[ 11.666645] pil-q6v5-mss fc880000.qcom,mss: modem: loading from 0x08000000 to 0x0d100000
<6>[ 11.667153] asoc: snd-soc-dummy-dai <-> SLIMBUS4_HOSTLESS mapping ok
<6>[ 11.668196] asoc: snd-soc-dummy-dai <-> VoLTE mapping ok
<3>[ 11.669309] init: cannot expand '${sys.sysctl.extra_free_kbytes}' while writing to '/proc/sys/vm/extra_free_kbytes'
& this is an interesting read, (not for the lazy) -
The State of Qualcomm's Modems - WTR1605 and MDM9x25
**comment from the article** -
iwod - Sunday, January 06, 2013 - link
"Interesting, i was late to the article and there is only 10 comments, compared to 3 page on ARM vs Atom. People not interested in LTE / Baseband at all??
Anyway, so do LTE UE 4 offer better bandwidth efficiency then UE 3? Since both only required 20Mhz, but UE 4 gives up to 150Mbps.
Apart from Beidou and TDS-CDMA, WTR1605 seems like a small step, no size reduction?
Are there any power improvement with 9x25? LTE seems to be draining battery a lot.
So i gathered all current Qualcomm already support VoLTE, we are only waiting for carrier to support it, right? And may be off topic, why aren't carrier doing it / Faster?
I am not sure if i am right, the more port there are, the more supported band / wireless spec there will be. It seems to be one of the reason iPhone 5 could not come with world wide LTE supported. So wouldn't ditching GSM help? ( 4G is here.... time to ditch 2G right? )
How do WiFi and Bluetooth fits into the scenario? They are all wireless tech, why do they requires another chip? Couldn't Qualcomm fits those in?
I remembered there was a article about Intel Digital Radio. I admit i still do not understand much of it. Any relation to this? Or is Digital Radio more on the antenna side of things."
**reply to that**-
DanNeely - Sunday, January 06, 2013 - link
"VoLTE increases the load on their 4g networks by reducing the load on 2g/3g; since 4g is only going to get more crowded with time while 2g is becoming a ghost town and 3g will become one in the next few years as LTE deployments are completed, VoLTE does nothing beneficial for the carriers in the short term.
Long term it's needed to let them shut down their legacy networks; but that's at least 4-5 years out according to occasional talking points they make (and if Sprint/iDEN is any indication even farther out in the real world) which makes it not worth enabling for handsets that will probably be junked well before it happens."
...........
we can deduct, that all current qualcomm chipsets have the VOlte feature baked in (but dormant for some odd reason);
tmobile, enables it on selected handsets via a pushed software update, not via an updated **VOlte sim** = Generic Bootstrapping Architecture
&
Subscriber Authentication in the IP Multimedia Subsystem
..
~shrugz shoulderz~

Probably to tie you into T-Mobile branded handsets where they make huge margins. Same as Wi-Fi calling.
Sent from my Nexus 5 using Tapatalk

rootSU said:
Probably to tie you into T-Mobile branded handsets where they make huge margins. Same as Wi-Fi calling.
Sent from my Nexus 5 using Tapatalk
Click to expand...
Click to collapse
i know how it works now;
the tmobile update *FULLY* enables the sip protocol on it's IMS ( IP Multimedia Subsystem) to match what's dormant in the phone ALREADY..
it's basically SIP ( with heightened QoS) -
read that - http://www.howardforums.com/showthread.php/1833821-Tmobile-launches-VoLTE-in-Seattle/page6
then
this - http://lteuniversity.com/get_trained/expert_opinion1/b/bbest/archive/2012/12/17/the-volte-conversation-between-ims-and-lte.aspx
...voLTE basically , speaks in SIP (session initiated protocol) -
http://www.sharetechnote.com/html/Handbook_LTE_VoLTE.html - the picture in this link with the raw network traffic can be mimicked with a tmobile sanctioned volte device, tethered wirelessly to a laptop in promicous mode, with wireshark or tcpdump, with the right arguments, or both, & with the said tmobile phone in a call session, the packets can be dumped & analyzed afterwards..

j'vai said:
i know how it works now;
the tmobile update *FULLY* enables the sip protocol on it's IMS ( IP Multimedia Subsystem) to match what's dormant in the phone ALREADY..
it's basically SIP ( with heightened QoS) -
read that - http://www.howardforums.com/showthread.php/1833821-Tmobile-launches-VoLTE-in-Seattle/page6
then
this - http://lteuniversity.com/get_trained/expert_opinion1/b/bbest/archive/2012/12/17/the-volte-conversation-between-ims-and-lte.aspx
...voLTE basically , speaks in SIP (session initiated protocol) -
http://www.sharetechnote.com/html/Handbook_LTE_VoLTE.html - the picture in this link with the raw network traffic can be mimicked with a tmobile sanctioned volte device, tethered wirelessly to a laptop in promicous mode, with wireshark or tcpdump, with the right arguments, or both, & with the said tmobile phone in a call session, the packets can be dumped & analyzed afterwards..
Click to expand...
Click to collapse
@galfert.. now that we KNOW at it's heart, VOlte speaks sip, it would be work to mimc the sip settings from another tmobile VOlte phone to a nexus 5 on the tmobile network..
it'll be lengthy, adding the bearer info, secondary bearer info, number + proper sip addy, & parking it on lte..
*BUT* it wouldn't work STILL, unless the UE (user equiptment) gets the OK'd update on tmobile's IMS gateway, *TO* set up & tear down the voice bearer connection with properly enhanced Q0S offered by the IMS..
the sip setting for the nexus 5 are in the phone setting for internet calls, & actually, i'll plug a thread started in here from 13 on this very subject -
Nexus 5 - Internet Calling Experience/SIP Thread by BinkXDA ..
the tools are in the device, but aren't complete from the network perspective..
& yet, i know NOT if tmobile could fashion this update for phone(s) a lil bit more heavier, where those un-known fields needed, are automatically populated.. maybe they're working on that for the future..

Here is something else to consider. T-Mobile has WiFi calling. Google Voice users for a long time have used apps to do VoIP over Google Talk XMPP and still can despite it being past the date. So who is to say an app couldn't just do it or they couldn't use just the SIP part of the phone app? Get the right codec and it is golden.
Sent from my Nexus 5 using XDA Free mobile app

MrObvious said:
Here is something else to consider. T-Mobile has WiFi calling. Google Voice users for a long time have used apps to do VoIP over Google Talk XMPP and still can despite it being past the date. So who is to say an app couldn't just do it or they couldn't use just the SIP part of the phone app? Get the right codec and it is golden.
Sent from my Nexus 5 using XDA Free mobile app
Click to expand...
Click to collapse
you're so right...
i use groove IP to call over lte, evdo, & wifi at times, after tinkering with the echo settings, it's as clear as any voice call..
only with the tmobile volte set up, the plus is you're using your same mobile number still (google snatched that away when breaking xxmp protocol in gv) ..
but with adjusting, the QoS can be just as good as your connection allows the call to be.. mine's is with groove IP / ring.to

I asked T-Mobile's technical guru about it a while back, here's what I got:
https://twitter.com/askdes/status/469582255191388160

Hilbe said:
I asked T-Mobile's technical guru about it a while back, here's what I got:
https://twitter.com/askdes/status/469582255191388160
Click to expand...
Click to collapse
https://twitter.com/TMobileHelp/status/479798004627427328
from 20 days ago.

Sorry for digging up this old thread, but after reading the how-does-VoLTE-work article, there's a point that nobody has mentioned yet...
While engaged in a voice call, a user might pass outside of an LTE coverage area, so that call needs to be able to fall back onto legacy networks. The VoLTE standard accomplishes this with Single Radio Voice Call Continuity (SR-VCC).
[...]
SR-VCC requires the network provider to have the IMS framework in place, but it also impacts device design. To support SR-VCC, devices must not only be able to connect to both the LTE and the legacy networks, but be able to connect to both at the same time. This is governed by the antenna architecture in the device. In order to conserve space, some devices, like the iPhone 5, will have 3G and 4G traffic sharing the same physical antennae, toggling between the two standards as needed. SR-VCC requires devices to have dedicated antennae for both 3G and 4G connections.
Click to expand...
Click to collapse
I may be mistaken about this, but the antenna is shared on the Nexus 5, isn't it? So it cannot support the LTE-to-3G handoff and as a result may never support VoLTE...

I've read it cannot, but by the time this technology is rolled out in a major way the phone will be verging on obsolete, I'm still happy with mine though

code65536 said:
Sorry for digging up this old thread, but after reading the how-does-VoLTE-work article, there's a point that nobody has mentioned yet...
I may be mistaken about this, but the antenna is shared on the Nexus 5, isn't it? So it cannot support the LTE-to-3G handoff and as a result may never support VoLTE...
Click to expand...
Click to collapse
Just watched a disassembly video on YT and he showed the Nexus 5 has two antennas. One for 2/3G and one for LTE.
Gesendet von meinem C5502 mit Tapatalk

Any confirmation on this?

I also only saw two antennas as I replaced my screen.
Ifixit.com says its MIMO and GPS antenna:
https://www.ifixit.com/Teardown/Nexus+5+Teardown/19016/[URL]

Any confirmation? Any help?

Related

[Q] Secret / Dialer Codes for Galaxy Tab 7.7

Hello,
I've noticed that most of the well knwon Samsung Secret and Dialer Codes are not working on the new Galaxy Tab 7.7 P6800. Are there known solutions for this? Other codes that are working?

I noticed the same thing.

RiverSource said:
Hello,
I've noticed that most of the well knwon Samsung Secret and Dialer Codes are not working on the new Galaxy Tab 7.7 P6800. Are there known solutions for this? Other codes that are working?
Click to expand...
Click to collapse
Yes all known USSD/MMI Codes are working on GINGERBREAD on my SGSII but not on SGT7.7 with HONEYCOMB. I think its cause HONEYCOMB

I have found, that some of the codes can be used with the App "SGS Secret Codes".
Since the codes are working, I think, they are filtered by the Dialer App.

RiverSource said:
I have found, that some of the codes can be used with the App "SGS Secret Codes".
Since the codes are working, I think, they are filtered by the Dialer App.
Click to expand...
Click to collapse
Only 2 of those codes work, the one to check the imei and another one which I font remember, the others nothing. Im looking for the one that shows the frequencies and you are able to enable/disable then. I wan to check what frequentcy my tab picks up while running T-Mobile sim
Sent from my SGH-T959 using XDA App

adinis78 said:
Only 2 of those codes work, the one to check the imei and another one which I font remember, the others nothing. Im looking for the one that shows the frequencies and you are able to enable/disable then. I wan to check what frequentcy my tab picks up while running T-Mobile sim
Sent from my SGH-T959 using XDA App
Click to expand...
Click to collapse
You mean this one? *#*#197328640#*#*
It works.
I'm still trying to find the *#*#9900#*#* one the works. Something to find and disable Fast Dormancy...

Jade Eyed Wolf said:
You mean this one? *#*#197328640#*#*
It works.
I'm still trying to find the *#*#9900#*#* one the works. Something to find and disable Fast Dormancy...
Click to expand...
Click to collapse
Yea thats the one i was refering to
Sent from my GT-P6800 using xda premium

Funny thing, i tried downloading the sgs codes app and now i have access to the frequency selector i have set up the tab to work on 1900mhz now i have to try and see if i can get full 3g+voice on tmobile. Will report back.
Sent from my GT-P6800 using xda premium

Maybe we can get in touch with the lidroid developer. I would like to have some other codes, like *#272*IMEI#. I will try it next week.

How about the lcd test menu?

Ok so while taking my dog out i took my tsb and wanted to see if it would pick up 3g with tmobile. and the result is, no. See the following and you will notice that 1900mhz is selected:
View attachment 888880
View attachment 888881
View attachment 888889
View attachment 888890
The first pic shows the tab connected at 1900mhz but if you look at the bottom right hand corner it shows as running on Edge. So maybe its picking up Sprints signal and Tmobile has not rolled out the 1900mhz over on the east coast?
EDIT: please let me know if you are able to see the pics. Everytime I go into the thread the pics are not coming up
Sent from my GT-P6800 using xda premium

No, the pics aren't displayed. I get the message, "Invalid attachment specified".

redb33s said:
No, the pics aren't displayed. I get the message, "Invalid attachment specified".
Click to expand...
Click to collapse
K thanks, ill repost by tomorrow
Sent from my SGH-T959 using XDA App

test menu code
EarlZ said:
How about the lcd test menu?
Click to expand...
Click to collapse
Please try this code, *#*#0*#*#*

Some codes that work
Did a lot of searching and found out a few that work
*#*#1234#*#* (To get the PDA/Phone/CSC versions)
*#*#0011#*#* (ServiceMode)
*#*#4636#*#* (Diagnostic and general settings mode)
You can see a pattern here...

adinis78 said:
So maybe its picking up Sprints signal and Tmobile has not rolled out the 1900mhz over on the east coast?
Click to expand...
Click to collapse
Nah, you're not going to be able to pick up Sprint anything, even if they use the same frequency bands; totally different technologies CDMA vs GSM/UMTS. Actually, believe it or not, UMTS has a lot in common with CDMA, but it's still not compatible. CDMA, specifically EV-DO, uses 1.25mhz spectrum channeling for it's available bandwidth. Also, it's simply a data stack, hence the "DO" in EV-DO (stands for Data Optimized). Modern CDMA networks still rely on a 1xRTT network for their voice stack. Because both stacks are separated by two different technology standards, the phone device can only really use one at a time. It is theoretically possible to do both, but that would require essentially two modems, one dedicated for voice, and one dedicated for data, but cost and complexity likely make that prohibitive. Instead, it's cheaper for CDMA devices to incorporate a modem that switches between the two stacks (voice/data) on demand, while keeping the idle stack on hot standby. That's why CDMA phones can't do data and voice simultaneously (easily).
UMTS (AKA WCDMA, or Wideband CDMA) on the other hand, is a whole different ball game. Because UMTS is technically a CDMA based technology, it also utilizes code division multiplexing as opposed to the time division multiplexing scheme used by legacy GSM. However, that's about where the similarities end. UMTS uses 5mhz spectrum channeling (4x the channel bandwidth of traditional CDMA/EV-DO!). Also, both voice and data are separated logically, instead of physically, by using dedicated slices of that 5mhz for their respective tasks. Essentially, part of that 5mhz channel will be dedicated to circuit switched voice access, and the remaining channel bandwidth is dedicated to packet switched data. In this way, a single modem can be easily used to perform both voice and data simultaneously because both protocol stacks are rolled into one nice neat package.
To draw an analogy, think of CDMA like having two plates of some Mexican food. One plate has your veggies (like your beans and rice), and the other plate has your meat (like your beef, chicken, or pork). By protocol standards, you're only allowed to eat from one plate at a time.
With UMTS, you're basically taking all those same ingredients, and rolling it all together into a burrito!
P.S. I've tried enabling the 1700mhz band via the service menu, and attempted to get 3G signal on a T-Mobile SIM, but no luck. No 1900mhz T-Mo 3G in the Washington DC area either btw.

Ok here are pics that didnt load on my original post
Sent from my GT-P6800 using xda premium

Jade Eyed Wolf said:
Nah, you're not going to be able to pick up Sprint anything, even if they use the same frequency bands; totally different technologies CDMA vs GSM/UMTS. Actually, believe it or not, UMTS has a lot in common with CDMA, but it's still not compatible. CDMA, specifically EV-DO, uses 1.25mhz spectrum channeling for it's available bandwidth. Also, it's simply a data stack, hence the "DO" in EV-DO (stands for Data Optimized). Modern CDMA networks still rely on a 1xRTT network for their voice stack. Because both stacks are separated by two different technology standards, the phone device can only really use one at a time. It is theoretically possible to do both, but that would require essentially two modems, one dedicated for voice, and one dedicated for data, but cost and complexity likely make that prohibitive. Instead, it's cheaper for CDMA devices to incorporate a modem that switches between the two stacks (voice/data) on demand, while keeping the idle stack on hot standby. That's why CDMA phones can't do data and voice simultaneously (easily).
UMTS (AKA WCDMA, or Wideband CDMA) on the other hand, is a whole different ball game. Because UMTS is technically a CDMA based technology, it also utilizes code division multiplexing as opposed to the time division multiplexing scheme used by legacy GSM. However, that's about where the similarities end. UMTS uses 5mhz spectrum channeling (4x the channel bandwidth of traditional CDMA/EV-DO!). Also, both voice and data are separated logically, instead of physically, by using dedicated slices of that 5mhz for their respective tasks. Essentially, part of that 5mhz channel will be dedicated to circuit switched voice access, and the remaining channel bandwidth is dedicated to packet switched data. In this way, a single modem can be easily used to perform both voice and data simultaneously because both protocol stacks are rolled into one nice neat package.
To draw an analogy, think of CDMA like having two plates of some Mexican food. One plate has your veggies (like your beans and rice), and the other plate has your meat (like your beef, chicken, or pork). By protocol standards, you're only allowed to eat from one plate at a time.
With UMTS, you're basically taking all those same ingredients, and rolling it all together into a burrito!
P.S. I've tried enabling the 1700mhz band via the service menu, and attempted to get 3G signal on a T-Mobile SIM, but no luck. No 1900mhz T-Mo 3G in the Washington DC area either btw.
Click to expand...
Click to collapse
We all know that we cant get 3g on 1700mhz with tmobile only edge thats why i wanted to see if enabling 1900mhz would work. But i wonder how i am picking it up if tmobile has not implemented it here on the east coast, guess ill just have to keep waiting until they do. No point in calling tmobile and ask them as i am sure they would not have any clue.
Sent from my GT-P6800 using xda premium

phseet said:
Did a lot of searching and found out a few that work
*#*#1234#*#* (To get the PDA/Phone/CSC versions)
*#*#0011#*#* (ServiceMode)
*#*#4636#*#* (Diagnostic and general settings mode)
You can see a pattern here...
Click to expand...
Click to collapse
Go to the market and download the sgs secret codes app it will give you a bunch of codes
Sent from my GT-P6800 using xda premium

adinis78 said:
Ok here are pics that didnt load on my original post
Sent from my GT-P6800 using xda premium
Click to expand...
Click to collapse
Having looked at your pictures there, it looks like you're connecting on GSM 1900 (which T-Moblie does support). This is 2G, not 3G/4G. If it were, GSM would be replaced by UMTS or something. See my pic in the attachment.
Also, see how it says WCDMA 1900 Band 2? It'll tell you if it's using UMTS/WCDMA or not.

Does Mi4 have LTE now?

Planning to buy a new Mi4 from kijiji. Wondering whether it supports LTE bands in Canada? I;'m with telus

Short answer. No, not yet.

veladem said:
Short answer. No, not yet.
Click to expand...
Click to collapse
OK.Thanks
Is this a software issue or the LTE version is a different hardware in the future? In other words, if i buy the mi4 now, will i be able to get LTE when its available?

Sadly it seems to be a hardware limitation. Xiaomi was smart when they made the phone and only have it what it needed unlike some companies that overlook the small things and pay in the end.

yes it does not. as no opomart and other sites are selling FDD-LTE version which 1700/2100 works perfect with ATT / T-Mobile in US

4G:FDD-LTE 1800(B3)/2100(B1)MHz

This may seem far fetched but I'll ask anyway. Is there a way to change the hardware frequencies set within the phone to match the connectivity frequencies that's in your area?

shakim24 said:
This may seem far fetched but I'll ask anyway. Is there a way to change the hardware frequencies set within the phone to match the connectivity frequencies that's in your area?
Click to expand...
Click to collapse
In theory, the chip should support them. It would be a matter of writing the specific band values into your phones memory (NV). However, this pre-supposes that the phone could be modified on that level to begin with, which is doubtful.
You would need:
Unlock/root
Custom rom
Custom kernel
QPST (for editing)
QXDM (write enabling)
access to switch usb diagnostic mode
The majority of the work would be getting around MIUI and Qualcomm's restrictions they implement in their code. While not impossible, as you can see, the changes required aren't necessarily for the faint of heart. I suppose one upside would be the phone doesn't cost an arm and a leg, so if you wound up with a brick, you might have an easier time bouncing back from the loss.

kibmikey1 said:
In theory, the chip should support them. It would be a matter of writing the specific band values into your phones memory (NV). However, this pre-supposes that the phone could be modified on that level to begin with, which is doubtful.
You would need:
Unlock/root
Custom rom
Custom kernel
QPST (for editing)
QXDM (write enabling)
access to switch usb diagnostic mode
The majority of the work would be getting around MIUI and Qualcomm's restrictions they implement in their code. While not impossible, as you can see, the changes required aren't necessarily for the faint of heart. I suppose one upside would be the phone doesn't cost an arm and a leg, so if you wound up with a brick, you might have an easier time bouncing back from the loss.
Click to expand...
Click to collapse
Thanks for the insight bro. You really broke down into detail what was needed to be done. Was scrolling around and found this thread http://forum.xda-developers.com/showthread.php?t=2871269. Would like your opinion on it. It's for unlocking LTE as well.

I think they released the LTE-FDD version , seach for it!

already got one with LTE...its out already

Hi, I don't know how helpful this is for you but I have bought two from China for myself and my wife. Although I have not tried on the MIUI OS, I have flashed AOSP on to both phones and they both work at least on O2 and EE. I am receive 4G on my EE Mi4, however my wife does not have a 4G sim so can not confirm hers but she does receive 3G signals.
O2s 4G sim did not receive 4G signals on my Mi4 though (reason for me switching)
Hope this helps you

Only bands 1, 3, 41

Which band is missing on the N920T from the N920A?

I'm having a hard time finding a definitive answer about which LTE band I'll lose using the tmobile variant on att.

I don't think any, I think both are identical. I am using the N920T with AT&t. I would suggest you consider using DarthStalkers ROM, he was able to pull the AT&T carrier files.
The N920T & A are the same. If you had bought the N920I you might lose bands.

Does anyone know where I can get a band 12 coverage map? I can only find the LTE coverage map which doesn't specify if band 12 is used there

wdkingery said:
I'm having a hard time finding a definitive answer about which LTE band I'll lose using the tmobile variant on att.
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Click to collapse
17 and 30 (I don't think the 920t's band 12 will work with AT&T's B17 - even though 12 is a subset of 17 (or do I have that backwards?) Possibly 29 (downlink only for AT&T) - but there's very little documentation on B29, so I'm not sure if the N920A supports it or not.

garyd9 said:
17 and 30 (I don't think the 920t's band 12 will work with AT&T's B17 - even though 12 is a subset of 17 (or do I have that backwards?) Possibly 29 (downlink only for AT&T) - but there's very little documentation on B29, so I'm not sure if the N920A supports it or not.
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Click to collapse
Could you be so kind as to translate what that will mean to me? I have a t-mobile note 4 here on att and it seems to do fine.. Do you think I'll be so lucky with the note 5?

wdkingery said:
Could you be so kind as to translate what that will mean to me? I have a t-mobile note 4 here on att and it seems to do fine.. Do you think I'll be so lucky with the note 5?
Click to expand...
Click to collapse
Band 29 is rarely used by AT&T (only as a downlink in heavily congested areas.) This shouldn't be a problem.
Band 30 (WCS band) is something AT&T _just_ started deploying, but I've never seen it in actual use. In fact, until very recently, none of AT&T's own phones supported it. B30 is really of limited value for general use due to it's propagation (or lack thereof.) Like 29, its probably only used as a supplement to other bands. I wouldn't worry about B30.
B17, however, is a Big Deal for AT&T. That's AT&T's primary "lower frequency" LTE band. Because of the low frequency, it has excellent propagation (meaning it moves farther and through trees, buildings, etc.) They use this band to cover large geographical areas with minimal towers. If you will be using your phone in a non-urban area, B17 is almost essential for AT&T. (My phone spends the majority of the time at my home on B17.)
I haven't heard of anyone with a TMO Note 5 device (without explicit B17 support) attaching to AT&T's B17, but that doesn't mean it won't work. However, Unless someone confirms B17 functionality on the n290T from actual use (and not just what they think), I'd suggest assuming that it won't work.

garyd9 said:
Band 29 is rarely used by AT&T (only as a downlink in heavily congested areas.) This shouldn't be a problem.
Band 30 (WCS band) is something AT&T _just_ started deploying, but I've never seen it in actual use. In fact, until very recently, none of AT&T's own phones supported it. B30 is really of limited value for general use due to it's propagation (or lack thereof.) Like 29, its probably only used as a supplement to other bands. I wouldn't worry about B30.
B17, however, is a Big Deal for AT&T. That's AT&T's primary "lower frequency" LTE band. Because of the low frequency, it has excellent propagation (meaning it moves farther and through trees, buildings, etc.) They use this band to cover large geographical areas with minimal towers. If you will be using your phone in a non-urban area, B17 is almost essential for AT&T. (My phone spends the majority of the time at my home on B17.)
I haven't heard of anyone with a TMO Note 5 device (without explicit B17 support) attaching to AT&T's B17, but that doesn't mean it won't work. However, Unless someone confirms B17 functionality on the n290T from actual use (and not just what they think), I'd suggest assuming that it won't work.
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An informative post if ever there was one indeed.
What app do you use to determine which hand your phone is connected thru? I have found this app "LTE discovery", and it seems my att note 3 stays connected to 5 mostly, or 4 for lte. But then for GSM is doesn't list a band, but appears connected. On her t-mobile note 4 connected to att, she stays on 5, but the GSM doesn't appear to be connected to anything..
We will be almost exclusively in the middle of a city, but as with anything that could change or in the event of a road trip..
Is there a place I can sit and study this information? Perhaps a website with all of this data? Or do you happen to work in the field?
In a sea of noobs, an informed person is a real diamond in the rough - I appreciate your time.

wdkingery said:
What app do you use to determine which hand your phone is connected thru? I have found this app "LTE discovery", and it seems my att note 3 stays connected to 5 mostly, or 4 for lte.
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Click to collapse
That's a good app to use. I also use my phone's diagnostic menu's, but I doubt AT&T left those enabled on the 'a' variant.[/QUOTE]
wdkingery said:
But then for GSM is doesn't list a band, but appears connected. On her t-mobile note 4 connected to att, she stays on 5, but the GSM doesn't appear to be connected to anything..
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Click to collapse
Is that with "lte discovery" that she doesn't appear to have any GSM side connection? She most likely does, as that's where voice calls will take place...
wdkingery said:
Is there a place I can sit and study this information? Perhaps a website with all of this data?
Click to expand...
Click to collapse
Google. Then google some more. If you run out of pages from google, use another search engine. All the information is readily available - it just takes time to find it all.

garyd9 said:
That's a good app to use. I also use my phone's diagnostic menu's, but I doubt AT&T left those enabled on the 'a' variant.
Click to expand...
Click to collapse
Is that with "lte discovery" that she doesn't appear to have any GSM side connection? She most likely does, as that's where voice calls will take place...
Google. Then google some more. If you run out of pages from google, use another search engine. All the information is readily available - it just takes time to find it all.[/QUOTE]
so i got through all the hoops.. don't have LTE ;-(
it connects to band 4 or 5 when i first come out of airplane mode, but it jumps right back off. stuck on 4g. called at&t for an hour, they said initially it wasn't provisioned on my sim card, but then afterwards they determined it was a problem on my end, walked my thru APN settings and then ended the call.. still no LTE.
do you have an opinion of what i could do?

wdkingery said:
do you have an opinion of what i could do?
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Click to collapse
Quoting me in a thread was enough... didn't have to also PM me...
@TEKHD has a firmware that might work for you. Check it out over here: http://forum.xda-developers.com/tmo...h6-tekxodus-n5-urv1-00-00-lollipop-5-t3201869
He has apparently provided a mechanism that is working for other AT&T users... (probably via loading the AT&T RIL libs.)
I haven't tried this (and I don't even have a 't' variant myself.) On the other hand, a quick search of that thread seems to show that other people are having successes with AT&T sim's on 't' variant devices.
Good luck!
Gary

sorry about the double.
after a precursory examination, idon't see exactly what you are talking about in his thread..
is it a download?

garyd9 said:
Quoting me in a thread was enough... didn't have to also PM me...
He has apparently provided a mechanism that is working for other AT&T users... (probably via loading the AT&T RIL libs.)
Good luck!
Gary
Click to expand...
Click to collapse
the search feature doesn't appear to work for me; shows 0 results on att or at&t.. i'm having to sift thru all 114 pages by hand.

garyd9 said:
He has apparently provided a mechanism that is working for other AT&T users... (probably via loading the AT&T RIL libs.)
Gary
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i searched all 114 pages and didn't find reference to any of that.. now i know why search provided no results; there weren't any!
so i need to find the att ril libraries. how will i ever find that.

wdkingery said:
i searched all 114 pages and didn't find reference to any of that.. now i know why search provided no results; there weren't any!
so i need to find the att ril libraries. how will i ever find that.
Click to expand...
Click to collapse
Maybe that was the wrong firmware... it's something in the TMO dev section. Please search.

garyd9 said:
Maybe that was the wrong firmware... it's something in the TMO dev section. Please search.
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Click to collapse
i've searched the entire tmo dev section for term "at&t" and there are sparse hits; there is some conversation about CSC for a guy in canada getting his VoLTE working, but nothing on att.

wdkingery said:
i've searched the entire tmo dev section for term "at&t" and there are sparse hits; there is some conversation about CSC for a guy in canada getting his VoLTE working, but nothing on att.
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Click to collapse
Apparently, you already found it: http://forum.xda-developers.com/tmo...on-1-aroma-t3212091/post63516726#post63516726
This has AT&T RIL's in the update.zip, and from a quick look at the first post in that thread, they are installed based on an aroma installer. Others in that thread claim it works for them. You're using a TMO device on ATT, so you have to expect some level of incompatibility. There are AT&T LTE bands that the TMO device simply doesn't support. It doesn't matter what happens with your Note 4. Different device and different modem.
So, if you want to use a TMO device on ATT, you'll have to make some sacrifices. Most people will find the sacrifices are less drastic using an international version of the phone. For some reason, US carriers go out of their way to ensure their devices are incompatible with each other.

garyd9 said:
Apparently, you already found it: http://forum.xda-developers.com/tmo...on-1-aroma-t3212091/post63516726#post63516726
This has AT&T RIL's in the update.zip, and from a quick look at the first post in that thread, they are installed based on an aroma installer. Others in that thread claim it works for them. .
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Click to collapse
ok this is where i started, by flashing the ATT option for this rom. but that doesn't solve the problem. i'm in the process of clean flashing the tmobile choice like he suggested.
thanks for all your help.
i'm afraid this isn't going to work either. i realize the wife's note 4 may have different hardware, and isn't a good reference.
i can see the thing connect to band 5, then band 4, lte .. but it's in "emergency calls only" mode, then it gives up on that, connects to HSUPA or HSPA+ and that's the last of an LTE connection.
i feel like it would connect if it could, and that i'm having a software issue.

problem solved guys sorry for the large headache..
Solution:
AT&T did not recognize my IMEI as being LTE capable. Because of that, they decline to allow my phone to connect to LTE. My phone would connect to an LTE tower (as in the screen shots a few pages back), but wouldn't receive anything back from AT&T, so it would say "emergency calls only" and then give up after about 10 seconds, and then never go back. Crap data all around at this time.
What you'll need to do is walk into an AT&T store, take a picture of the IMEI off an LTE phone, and then call in and change your IMEI to the phone you found. This will cause the system to recognize your phone as LTE capable, and like magic, you'll have LTE.

I can confirm that I have a tmobile branded unit that attaches to band 17. It isn't as frequently as on my note 4, I'm generally on band 2. With that said I've had virtually no trouble with service. I was initially worried about the b17 issue, but it hasn't seemed to make any difference.

intifadamericana said:
I can confirm that I have a tmobile branded unit that attaches to band 17. It isn't as frequently as on my note 4, I'm generally on band 2. With that said I've had virtually no trouble with service. I was initially worried about the b17 issue, but it hasn't seemed to make any difference.
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Click to collapse
Does it attach to band 17 on AT&T or t-mobile?

VoWiFi (Wi-Fi calling) Moto G 2015 Osprey

Hello All,
In my new home is very low T-Mobile signal strength.
As i know from carrier official page, T-Mobile supports VoLTE and VoWiFi (Wi-Fi calling) in my country.
Now (6 july 2017) i have installed newest LineageOS build. There no option to enable Wi-Fi Calling/VoWiFi, but regarding to official Qualcomm site Osprey's processor (Snapdagon 410) supports Wi-Fi Calling/VoWiFi:
Next-generation Calling Services
Voice over Wi-Fi (VoWiFi) with LTE call continuity
HD Voice over 3G and VoLTE
It is posible to enable Wi-Fi Calling/VoWiFi on Osprey?
This solution does not work. When i make Wi-Fi Calling enable it going back to off.
Device: Moto G 2015 (XT1541)
Country: Poland
Carrier: T-Mobile
ROM: LineageOS 14.1 build from 6 july 2017

mrViZhy said:
Hello All,
In my new home is very low T-Mobile signal strength.
Is i know from carrier official page, T-Mobile supports VoLTE and VoWiFi (Wi-Fi calling) in my country.
Now (6 july 2017) i have installed newest LineageOS build. There no option to enable Wi-Fi Calling/VoWiFi, but regarding to official Qualcomm site Osprey's processor (Snapdagon 410) supports Wi-Fi Calling/VoWiFi:
Next-generation Calling Services
Voice over Wi-Fi (VoWiFi) with LTE call continuity
HD Voice over 3G and VoLTE
It is posible to enable Wi-Fi Calling/VoWiFi on Osprey?
This solution does not work. When i make Wi-Fi Calling enable it going back to off.
Device: Moto G 2015 (XT1541)
Country: Poland
Carrier: T-Mobile
ROM: LineageOS 14.1 build from 6 july 2017
Click to expand...
Click to collapse
FYI For U.S. prepaid T-mobile accounts: T-Mobile may require address and other information to be entered on their website into the account profile for that phone #. If that information is entered on-line and the account has WiFi calling properly enabled it should work when the device has wifi connection and no cellular connection. This is not dependent on any settings on the phone and should work even if you don't see any settings there. You might want to contact your provider about this.

mrViZhy said:
... It is posible to enable Wi-Fi Calling/VoWiFi on Osprey?
This solution does not work. When i make Wi-Fi Calling enable it going back to off.
Device: Moto G 2015 (XT1541)
Country: Poland
Carrier: T-Mobile
Click to expand...
Click to collapse
No, it doesn't work, not with T-Mobile. It won't stay on, no matter what you do.
I have MetroPCS/T-mobile USA, and I have had the exact same issue. I've had no problems using wifi calling on my same account with other phones, but not this one (they do require you to register your full info here, as the last poster said). T-mobile support themselves have told me, however, they only allow wifi calling on phones purchased directly from them, and that's why no go, at least not in the USA. I'm assuming that's their policy in other countries, too?
I don't know if there is a hack/workaround.
Side note: When I go to Europe, which is often, I re-register my old, official t-mobile phone with t-mobile usa, leave my US sim in it, and I use that phone thru wifi calling to still have a US phone while there. I throw a UK sim in my Moto G to use every day.

beachfl said:
No, it doesn't work, not with T-Mobile. It won't stay on, no matter what you do.
I have MetroPCS/T-mobile USA, and I have had the exact same issue. I've had no problems using wifi calling on my same account with other phones, but not this one (they do require you to register your full info here, as the last poster said). T-mobile support themselves have told me, however, they only allow wifi calling on phones purchased directly from them, and that's why no go, at least not in the USA. I'm assuming that's their policy in other countries, too?
I don't know if there is a hack/workaround.
Side note: When I go to Europe, which is often, I re-register my old, official t-mobile phone with t-mobile usa, leave my US sim in it, and I use that phone thru wifi calling to still have a US phone while there. I throw a UK sim in my Moto G to use every day.
Click to expand...
Click to collapse
From what I understand, I could be wrong though, T-Mobile open sourced their WiFi calling and anybody can implement it but LineageOS haven't done it yet. It's a matter of adding the code (just like VoLTE) I think. I don't think T-mobile checks if it's their phone or not, the right software need to run, that's all. The problem is that the software is very low level and needs to part of the kernel, you can't just install some app and make it work. This is what I found when I did my search for LineageOS and WiFi calling a few months back. from T-Mobile forums. Of course anybody can post anything in those forums so it's not official or anything but a few users provided the same answer (some seemed quite knowledgeable) so I believe this is it (probably better than talking so some phone rep reading off FAQ's haha)

rb1979 said:
From what I understand, I could be wrong though, T-Mobile open sourced their WiFi calling and anybody can implement it but LineageOS haven't done it yet. It's a matter of adding the code (just like VoLTE) I think. I don't think T-mobile checks if it's their phone or not, the right software need to run, that's all. The problem is that the software is very low level and needs to part of the kernel, you can't just install some app and make it work. This is what I found when I did my search for LineageOS and WiFi calling a few months back. from T-Mobile forums...
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It's not unheard of for mobile providers to do just what I'm suggesting t-mobile does. In the UK, for example, Vodafone limits WiFi calling even further than that, to only a few select Voda-sold models (or at least it was like that when I was there recently).
I would very much appreciate being pointed in the direction of guidance by anyone who's been successful in getting it to work on any non-tmobile handset, custom ROM/kernel or not. Thanks much x

IronTechmonkey said:
FYI For U.S. prepaid T-mobile accounts: T-Mobile may require address and other information to be entered on their website into the account profile for that phone #. If that information is entered on-line and the account has WiFi calling properly enabled it should work when the device has wifi connection and no cellular connection. This is not dependent on any settings on the phone and should work even if you don't see any settings there. You might want to contact your provider about this.
Click to expand...
Click to collapse
Hi IronTechmonkey, at first I took it as a fact but later I thought about it and now I'm thinking how would WiFi calling work without LinageOS having code for it. Once you're outside of their network and T-Mobile (others too of course) can't get to your phone through SIM card the only way for anything to work is if the software on the phone through the internet first contacts the provider, correct me wrong but how would the provider get to you? This is just my thinking about it so I'm not sure but what common sense tells. I have the address on T-mobile and everything setup but since I'm not NJ where coverage is everywhere it's not easy for me test it but I'm scared without LineageOS actually getting on top of it and implementing the code it's not going to work. I'll test it once I go somewhere with no coverage but haven't had a chance yet.

rb1979 said:
Hi IronTechmonkey, at first I took it as a fact but later I thought about it and now I'm thinking how would WiFi calling work without LinageOS having code for it. Once you're outside of their network and T-Mobile (others too of course) can't get to your phone through SIM card the only way for anything to work is if the software on the phone through the internet first contacts the provider, correct me wrong but how would the provider get to you? This is just my thinking about it so I'm not sure but what common sense tells. I have the address on T-mobile and everything setup but since I'm not NJ where coverage is everywhere it's not easy for me test it but I'm scared without LineageOS actually getting on top of it and implementing the code it's not going to work. I'll test it once I go somewhere with no coverage but haven't had a chance yet.
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Click to collapse
Good question. I wasn't being quite clear enough in replying, and was speaking to whether or not there would be settings in the ROM if the feature exists, but was not speaking to whether or not the code is present. To the point of your question, from general web searching this seems to be device/ROM-build specific but when I search specifically for Lineage OS Osprey wifi-calling I find this thread. LOL. Apart from that this jira ticket for a different device is all I can find: https://jira.lineageos.org/browse/BUGBASH-508.

IronTechmonkey said:
Good question. I wasn't being quite clear enough in replying, and was speaking to whether or not there would be settings in the ROM if the feature exists, but was not speaking to whether or not the code is present. To the point of your question, from general web searching this seems to be device/ROM-build specific but when I search specifically for Lineage OS Osprey wifi-calling I find this conversations. LOL. Apart from that this jira ticket for a different device is all I can find: https://jira.lineageos.org/browse/BUGBASH-508.
Click to expand...
Click to collapse
Thanks, so I'm confused now, and thanks for your help. I know with VoLTE it was such a big deal we had whole posts about removing it and then bringing it back etc... all the updates and drama we need while nobody mentions even once if this device has wifi calling or not, haha, weird

I want to reopen this thread, I tried to ask in the official development opsrey thread but was sent to Q & A, so I'm reopening this thread. Anybody knows anything about Wi-Fi calling for osprey and LOS? Will it be implemented? Can I make a request somewhere? Maybe just switch to LOS 15 when it's official, will it have it on the arrival? I traveled outside of the US and did different tests and couldn't get Wi-Fi calling to work? Here's my post from the official osprey development thread with more detailed, thanks you, https://forum.xda-developers.com/showpost.php?p=73769962&postcount=5299
BTW, I made all necessary changes back in the USA with T-mobile to make Wi-Fi calling work, thanks.

So, WiFi Calling is unavailable as default option on any of ROMs for our devices.
BUT
For example, in Poland everybody who has Android higher than 4.1 can use "WiFi-calling" on "Orange" carrier. This carrier offers some application which realy works:
https://play.google.com/store/apps/details?id=pl.orange.vowifi&hl=pl
Functionality of this app is same, but i think it drains more battery than "wifi-calling" implemented as driver in kernel.

mrViZhy said:
So, WiFi Calling is unavailable as default option on any of ROMs for our devices.
BUT
For example, in Poland everybody who has Android higher than 4.1 can use "WiFi-calling" on "Orange" carrier. This carrier offers some application which realy works:
https://play.google.com/store/apps/details?id=pl.orange.vowifi&hl=pl
Functionality of this app is same, but i think it drains more battery than "wifi-calling" implemented as driver in kernel.
Click to expand...
Click to collapse
Thanks mrViZhy, actually I'm traveling from USA to Poland too. What I would like to do is keep the US number and receive text message (and pick up phone calls too) from US. I'm assuming your solution requires getting Orange number, if that's the case it would break the connection that I have with the US.
Thanks again for your help

LTE Band 12, VoLTE, and T-Mobile

I am starting this thread, since there seems to be a lot of confusion around "newer" LTE bands, like Band 12 on T-Mobile, which apparently require a fully functioning and "approved" VoLTE phone to get reception.
There are various threads in device-specific forums, but they are not getting a lot of attention, and this is a significant enough problem that it should be more visible.
T-Mobile at this point has pretty fantastic coverage via the 700MHz Band 12 LTE network.
The only problem is that Band 12 requires the phone to be VoLTE "certified". The rumor was that phones could still connect to this band/LTE-network and send/receive data, but that they would fall back to alternative bands, even 3G or 2G, for phone calls. For a lot of people that would be "good enough" if not ideal.
Based on some recent testing, this is NOT CORRECT:
While phones may "sometimes" connect to Band 12 for data, the much more common scenario is apparently that the phone will disconnect from Band 12 almost immediately, or will refuse to connect to Band 12, and will instead default to an alternative LTE, 4G, 3G, or 2G connection.
In other words: even if you have perfect LTE Band 12 coverage (5/5 bars, or 100%), your "Band 12 capable" phone may instead try to connect to a really ****ty GPRS or EDGE tower that has barely any reception for the phone.
I recently encountered this with my Xperia X Compact while travelling: My phone would barely be able to connect to a T-Mobile tower with a GPRS data connection, while my wife's Moto G4 would get 5/5 or 100% LTE reception. Swapping SIM cards had the same result, so we know the problem rests with the phone.
Searching for "Available Mobile Networks" on my "band 12 capable" phone would show various T-Mobile 4G networks, but the phone would be unable to connect to them.
Talking to other Xperia X Compact owners, they have the same problem: the phone will sporadically connect to Band 12, but it is not a reliable connection (if the phone even connects) and it will (more likely) prefer other networks/bands/frequencies.
Based on the phone having the proper frequencies, I would assume that T-Mobile has some mechanism on some (or the majority of) towers where they disconnect non-VoLTE certified devices.
Anecdotally, I also had a similar issue with my previous phone - a Nexus 5x. The phone is even VoLTE certified, but when using Cyanogenmod/LineageOS, it would have really terrible reception, despite the location having almost perfect Band 12 coverage - LineageOS/CM does not (or had no) VoLTE support.
I have also tried "hacking" the X Compact to enable VoLTE support by adding the relevant lines to the build.prop and enabling the option under Settings and (*#*#4636#*#*) but this does not appear to make any difference.
A list of T-Mobile "VoLTE certified" phones can be found here:
http://www.spectrumgateway.com/compatible-phones
Would be great if anyone has any suggestions how to resolve this, or force the phone to prioritize Band 12, but it would otherwise appear that the only solution is to get the phone certified by T-Mobile (so much for net neutrality and open access).

I'm using an Xperia X Compact and my home market only has band 12 lte and I can't connect to it. Which means I'm always in 3g or roaming and rarely have data in buildings. It's maddening because I will only buy Sony. I think they are the only manufacturer making attractive handsets and the build quality is light years beyond well marketed, poorly constructed brands like Samsung and LG. But regardless of anyone's choice of manufacturer, a device with a functioning 700 mhz lte radio should function just fine on the corresponding network regardless of where it was purchased.
Would certifying this device and enabling VOLTE be particularly costly to Sony? Correct me if I'm wrong but based on internal components this device should be capable of this ja?
I think it wouldn't hurt to send petitions to both the manufacturer and T-mobile USA. This certainly doesn't help Sony in a market they are seriously struggling in. It also isn't very uncarrier to favor certain devices over others.
The only reason I switched from Verizon was the ability to choose my device. That and the things John Legere was doing to change the industry. I believed in what he was saying. But right now it isn't working for me and likely many others. He should know. I can say firsthand that the guy answers his emails. I think we need to show both parties that this is worth their attention.
---------- Post added at 01:09 AM ---------- Previous post was at 12:14 AM ----------
I should mention that after multiple calls to T-mobile tech support I received a cryptic call very late at night from someone high up in tech support.
Long story short he at least admitted that even though it wasn't a t mobile device and even though it didn't support VoLTE, it should still connect to band 12 just fine. He also said that they were having problems with this sort of thing in my area and that it should be resolved in a month. He also said my IMEI was logged and I would be given priority in the matter. Whatever that means.
I should also mention that was a month ago and he didn't have an email to give me. He did however give me a phone number (probably just the department) that I need to dig up.
Could just be a bunch of fluff because they are afraid to lose customers. Then again he was from tech support not customer retention. And as I said t mobile does listen to its customers.

POMF2K said:
I'm using an Xperia X Compact and my home market only has band 12 lte and I can't connect to it. Which means I'm always in 3g or roaming and rarely have data in buildings. It's maddening because I will only buy Sony. I think they are the only manufacturer making attractive handsets and the build quality is light years beyond well marketed, poorly constructed brands like Samsung and LG. But regardless of anyone's choice of manufacturer, a device with a functioning 700 mhz lte radio should function just fine on the corresponding network regardless of where it was purchased.
Would certifying this device and enabling VOLTE be particularly costly to Sony? Correct me if I'm wrong but based on internal components this device should be capable of this ja?
I think it wouldn't hurt to send petitions to both the manufacturer and T-mobile USA. This certainly doesn't help Sony in a market they are seriously struggling in. It also isn't very uncarrier to favor certain devices over others.
The only reason I switched from Verizon was the ability to choose my device. That and the things John Legere was doing to change the industry. I believed in what he was saying. But right now it isn't working for me and likely many others. He should know. I can say firsthand that the guy answers his emails. I think we need to show both parties that this is worth their attention.
---------- Post added at 01:09 AM ---------- Previous post was at 12:14 AM ----------
I should mention that after multiple calls to T-mobile tech support I received a cryptic call very late at night from someone high up in tech support.
Long story short he at least admitted that even though it wasn't a t mobile device and even though it didn't support VoLTE, it should still connect to band 12 just fine. He also said that they were having problems with this sort of thing in my area and that it should be resolved in a month. He also said my IMEI was logged and I would be given priority in the matter. Whatever that means.
I should also mention that was a month ago and he didn't have an email to give me. He did however give me a phone number (probably just the department) that I need to dig up.
Could just be a bunch of fluff because they are afraid to lose customers. Then again he was from tech support not customer retention. And as I said t mobile does listen to its customers.
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Since I did encounter this also on my Nexus 5x with LineageOS, I doubt that what T-Mobile told you is true. They must be actively blocking these non-certified handsets, since the phone should just attempt connecting.

So who do we need to appeal to? T mobile or Sony.?

POMF2K said:
So who do we need to appeal to? T mobile or Sony.?
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Both. Maybe also complain to the FCC - I thought that carriers needed to provide open access to their network. Verizon got into hot water for not doing so ...

Does your compact ever connect to lte for a few seconds after a reboot?
I might try to force LTE and restart and see if that has any effect.
I just flashed the UK. T mobile networks work just fine. Well except lte/4g but that was expected.

POMF2K said:
Does your compact ever connect to lte for a few seconds after a reboot?
I might try to force LTE and restart and see if that has any effect.
I just flashed the UK. T mobile networks work just fine. Well except lte/4g but that was expected.
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It does connect sometimes but it then usually kicks down to Band 4 or a GSM band (HSDPA, UMTS, EDGE, or even GPRS).
I cannot find any info how to prioritize LTE bands, so I assume this is T-Mobile's band 12 cell tower's kicking the phone off when they notice that it is not VoLTE approved.

Interesting discussion on Howard forums....
http://www.howardforums.com/showthr...rtphones-with-band-12-LTE-w-o-VoLTE-now/page2

POMF2K said:
Interesting discussion on Howard forums....
http://www.howardforums.com/showthr...rtphones-with-band-12-LTE-w-o-VoLTE-now/page2
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Interesting discussion though nothing new.
Yes, we know that Band 12 phones should be able to get a data connection, yet T-Mobile apparently actively disconnects them (or bars them from connecting), especially in areas where Band 12 would give you great coverage but there is no other coverage.
F Sony and F T-Mobile for this!
BTW: here is an article about the follow up model: https://arstechnica.com/gadgets/2017/08/sony-xperia-xz1-compact/
Please leave comments about Sony not getting their phones approved for VoLTE with T-Mobile and the phone therefore NOT REALLY WORKING with the carrier.

It would seem to me that the only solution to this problem would be either T-Mobile accepting a standard spec for VoLTE, they open source their code for VoLTE, or someone figures out how to implement VoLTE and trick T-Mobile to think it is an approved "whitelisted" phone.
Given that the T-Mobile network is getting worse and worse every day without Band 12 coverage, I find it really surprising that most people just don't seem to care. Does nobody use their phone outside of WiFi?

andTab said:
It would seem to me that the only solution to this problem would be either T-Mobile accepting a standard spec for VoLTE, they open source their code for VoLTE, or someone figures out how to implement VoLTE and trick T-Mobile to think it is an approved "whitelisted" phone.
Given that the T-Mobile network is getting worse and worse every day without Band 12 coverage, I find it really surprising that most people just don't seem to care. Does nobody use their phone outside of WiFi?
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There is a standard spec, the problem is the certification. It requires a certificate from T-mobile to be used by the phone, which is gained through certification. And if SONY is detecting T-mobile at the modem level then there isn't anything a ROM can do with or without a ROM. I had a Z5, but this drove me crazy so I switched to a Pixel.
I wouldn't expect this to change based on SONY de-prioritizing the US phone market, so either upgrade to a new supported sony phone or move on (shrug)

sovanyio said:
There is a standard spec, the problem is the certification. It requires a certificate from T-mobile to be used by the phone, which is gained through certification. And if SONY is detecting T-mobile at the modem level then there isn't anything a ROM can do with or without a ROM. I had a Z5, but this drove me crazy so I switched to a Pixel.
I wouldn't expect this to change based on SONY de-prioritizing the US phone market, so either upgrade to a new supported sony phone or move on (shrug)
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That can't be true.
I accept that T-Mobile may issue a certificate but that must be processed on the rom/OS/phone.apk level. Otherwise, every custom ROM on any certified phone would work. We all know that is not the case.
If it's the rom/OS/phone.apk though, why can't we hack a phone to work with TMUS / VoLTE?
I have an x compact and while it is the best device I have ever owned it is essentially unusable on T-Mobile or att.

andTab said:
That can't be true.
I accept that T-Mobile may issue a certificate but that must be processed on the rom/OS/phone.apk level. Otherwise, every custom ROM on any certified phone would work. We all know that is not the case.
If it's the rom/OS/phone.apk though, why can't we hack a phone to work with TMUS / VoLTE?
I have an x compact and while it is the best device I have ever owned it is essentially unusable on T-Mobile or att.
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Because the SONY modem firmware doesn't even attempt to negotiate VoLTE, which does *not* happen in user space. It is likely possible to hack the qualcomm modem with QPST to enable this, but without documentation and correct values one will not get very far.

sovanyio said:
Because the SONY modem firmware doesn't even attempt to negotiate VoLTE, which does *not* happen in user space. It is likely possible to hack the qualcomm modem with QPST to enable this, but without documentation and correct values one will not get very far.
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If it was the modem, then flashing a new system (eg custom ROM) should not make any difference.
I also have a Nexus 5x. With stock it is fantastic and uses VoLTE on T-Mobile. With LineageOS, it is useless on Band 12. SAME MODEM!
Experience therefore shows that it is the OS/System that somehow prevents this from working.

andTab said:
If it was the modem, then flashing a new system (eg custom ROM) should not make any difference.
I also have a Nexus 5x. With stock it is fantastic and uses VoLTE on T-Mobile. With LineageOS, it is useless on Band 12. SAME MODEM!
Experience therefore shows that it is the OS/System that somehow prevents this from working.
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The Nexus 5x is a different phone made by a different manufacturer with a different firmware scheme. You cannot compare them directly.

I noticed that the XZ1 Compact says right on the website compatible with t mobile band 12 and wifi calling... this is infuriating. It should be easy for them to patch the Xperia x compact.
I would have never purchased this if I had known. Especially since they apparently flashed an update to my old t mobile z3 that allows voice over lte and band 12.

Sony X Compact
sovanyio said:
There is a standard spec, the problem is the certification. It requires a certificate from T-mobile to be used by the phone, which is gained through certification. And if SONY is detecting T-mobile at the modem level then there isn't anything a ROM can do with or without a ROM. I had a Z5, but this drove me crazy so I switched to a Pixel.
I wouldn't expect this to change based on SONY de-prioritizing the US phone market, so either upgrade to a new supported sony phone or move on (shrug)
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It has to be on Sony, use the t-mobile BYOD app to check, I have a Huawei mate 9 that I just purchased, connects perfectly on band 12, VoLTE works just like it's supposed to. On a side note I went through three Sony phones before I bought this Huawei, had to return all three due to quality control issues, one had worst touches that made the phone unusable, one wouldn't pick up the SIM card, and the third wouldn't power on at all, thank good Amazon refunded my money on all three. They may have the Sony name on the phone, but they are still build by the lowest bidder in China and makes with Sony's name.

revjamescarver said:
It has to be on Sony, use the t-mobile BYOD app to check, I have a Huawei mate 9 that I just purchased, connects perfectly on band 12, VoLTE works just like it's supposed to. On a side note I went through three Sony phones before I bought this Huawei, had to return all three due to quality control issues, one had worst touches that made the phone unusable, one wouldn't pick up the SIM card, and the third wouldn't power on at all, thank good Amazon refunded my money on all three. They may have the Sony name on the phone, but they are still build by the lowest bidder in China and makes with Sony's name.
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See this: http://www.androidpolice.com/2015/0...cked-smartphones-and-yep-its-still-confusing/ It is up to an OEM to decide to go through this process per-phone. Since no US carrier carried the phone they didn't not bother spending the money or time to certify it. I loved the SONY design, but since they weren't supporting the market I had to abandon them for other phones.

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