Database Users

On-the-fly carrier switching

Good evening!
I recently purchased the VZW S7. My immediate plan is to root it and then enable the Samsung carrier info (which VZW disables) so I can get to the engineering screens to check out LTE/network connection information.
I have been searching all over XDA for some type of answer to my question and haven't found it yet. What I can gather is the VZW variant has all the hardware requirements to have every band from every major carrier in the US, however VZW has disabled specific bands in their firmware. This lead me to thinking I will push the 930U firmware to it which, from what I have read here, unlocks all the specific bands as dictated by the SIM card currently inserted into the phone.
Here is my question: with the 930U firmware, how complicated is it to switch carriers on-the-fly, and to have all the bands a particular carrier utilizes?
My main line is VZW, but I also have a T-Mobile line on my Nexus 6P. However, there is zero engineering mode on the 6P, so I am unable to see information like current band, bandwidth, carrier aggregation status, etc. SignalCheck Pro only tells me the band.
So if I want to use the S7 on Verizon and then swap my T-Mobile SIM card in, how does the phone handle this, and it is a hassle once I put my VZW SIM back in?
I hope all this made sense. Essentially what I am wondering is if switching carriers on the fly is as easy as it is on the 6P- just pop the card in and go, with all the necessary LTE bands enabled.
Thank you for your time!

Complete debrand of LG G6

I was wondering if like Sony and Samsung devices, if it's possible to completely debrand a G6 to enable Wifi calling and VoLTE on a specific network's branded software? I know the G5 left the original operator's customisation files (unless rooting to change the cust folder) but has this changed with the G6?
Haven't bought the phone yet but seen an unlocked one which obviously wouldn't have network branded software.
Thanks.

Not sure of the purpose of this. So you want a completely unbranded phone and then want to install a specific network's software for wifi calling and VoLTE? If so, why not buy the phone from that network? Example: I bought an unlocked T-Mobile phone (on Amazon, not directly from T-Mobile) that can be used on any network, but contained T-Mobile software. I disabled what I didn't need. I am on T-Mobile anyway so I can use their wifi calling app.

patruns said:
Not sure of the purpose of this. So you want a completely unbranded phone and then want to install a specific network's software for wifi calling and VoLTE? If so, why not buy the phone from that network? Example: I bought an unlocked T-Mobile phone (on Amazon, not directly from T-Mobile) that can be used on any network, but contained T-Mobile software. I disabled what I didn't need. I am on T-Mobile anyway so I can use their wifi calling app.
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Purpose is that a second hand unlocked phone is much cheaper than one branded to the network at the moment.

wifi calling is mostly junk and over-rated feature. I know of no phones that can do a decent handoff in the event that wifi signal drops out of range then the phone wants to continue the call on LTE but if your LTE signal is already weak the call will just drop. Happened to me all the time so I just disable it and all the HD voice garbage too. Forcing back to the old 4G network thats now less congested than its ever been!

Admittedly wi-fi calling has only come in useful a handful of times, but the 4G calling feature has worked for me in a few places where 2G/3G is patchy. Guess I could do without it though.

Install Google Voice, hangouts, and hangouts dialer. Then you can use Wi-Fi or data calling in any phone or any rom.
I'm using a US997(16a) in Verizon and it works fine.

Spookymyo said:
Install Google Voice, hangouts, and hangouts dialer. Then you can use Wi-Fi or data calling in any phone or any rom.
I'm using a US997(16a) in Verizon and it works fine.
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Thanks, had those installed on my G5 but never used them. Will give it a go.

I switched from an S7 Edge, on which I was able to change the CSC Code and get features different Canadian Carriers had to offer. The particular one I was interested in was VoLTE(Video/Voice over LTE) video calling was the main feature I wanted to keep. That's why when I switched to the G6, I made sure it was from Rogers so I can continue to use that feature. It's pretty sweet... great quality video calling without using any data
I wish LG had a feature like this too, where you can change carrier settings on unlocked phones. It would be helpful

It would indeed be helpful! I guess I managed fine without the features before and it's not a huge loss but wi-fi calling definitely came in handy at a couple of places I used to work at.
IME Samsung and Sony phones were fairly easy to fully change carrier firmwares on and I remember HTCs being a pain (not sure what they're like now). But LGs seem to be able to debrand 90% of the firmware but still leave enough of a trace of the original software to block off a couple of features, which is slightly annoying. Ah well

Wifi Calling (T-Mobile) on Exynos s7 Edge

I bought an international s7 edge since the American Snap models have locked bootloaders. I flash custom roms and stuff, so Exynos was a must for me. However, since my phone wasn't made for the T-Mobile network, it's missing a few things
1) Video Calling results in "Unable to make Video Call to this number"
2) I have no way to toggle Wi-Fi calling, a feature I want to use since T-Mobile is charging for it
3) I have no idea if VoLTE is working or not, since there isn't a toggle under connections or the phone app
I remember on my TMO s6 edge+ most of these features were simple floatingfeature.xml codes that needed to be enabled. Unfortunately, I no longer have that phone and don't remember the codes, or know if adding these codes to an international will solve my problem. I would greatly appreciate any help you could offer, and thank you for reading!

? Using LG V20 H910 AT&T Model On T-Mobile After (2021) VoLTE Change

I posted this ? on reddit as well; however, this device is on its last legs so there's not much interest for it. I've gotten some good answers here and there on this website, but a dedicated thread to gather all the good info might be more helpful.
I still use my AT&T H910 as I don't really do much gaming on it. Calling, texting, and YouTube is what I mostly utilize it for. I just heard about the whole VoLTE requirement on specific devices after 2022 for AT&T, and 2021 for T-Mobile.
I spoke to AT&T, and they re-assured that the H910 was going to be one of the devices supported after 2022; however, I've been thinking about changing to T-Mobile (my family has a great plan with them, and I always switch back and forth between carriers based on who gives me the best deal) but I can't seem to get a straight answer from T-Mobile about whether my unlocked H910 will work with them after 2021; some didn't even know about the 2021 specifics of it.
I know AT&T will have to allow devices to be used on their network after 2022 even if they're VoLTE capable already. By the looks of it, T-Mobile won't go to that extreme; however, does anyone know exactly how VoLTE works? Specially in regards to using the AT&T H910 model on T-Mobile? Does my H910 has the required Bands to utilize VoLTE on T-Mobile? Or is it one of those things like "Wi-Fi Calling" where T-Mobile Wi-Fi calling only works with the LG V20 model from T-Mobile, and AT&T Wi-Fi calling only works with the LG V20 model from AT&T?

You need band 12 support which H910 has. Also a rom with IMS services working so no AOSP roms.
Volte works by using IMS processes in the rom to route phone calls over IP. No volte = no phone calls. But the device will still "work".
In theory the ATT software will work, unlock it and borrow someone else's sim. In theory a partial cross flash (just system, no modem/aboot/etc) could work if it doesn't.

nxb said:
You need band 12 support which H910 has. Also a rom with IMS services working so no AOSP roms.
In theory the ATT software will work, unlock it and borrow someone else's sim.
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I was recommended to use an app called Network Mode Universal on reddit for VoLTE testing purposes, and after inserting a T-Mobile SIM card that I borrowed on my unlocked H910 and using the application, the Voice Network Type tab says "LTE". Which is supposed to be a sign that VoLTE might be working on the H910 using a T-Mobile SIM, but that's all I know; just what people tell me.
Update:
The person who recommended that Network Mode Universal app forgot to mention that you have to actually make a call to know whether the phone supports VoLTE with the SIM card in use. When actually making a call, the Voice Network Type tab changes from "LTE" to "UMTS". Which means the H910 is not VoLTE capable on T-Mobile.
Sent from my LG-H910 using Tapatalk

Could also be how his sim is set up. Volte has to be enabled there and in the phone. My suggestion would be to force LTE only on the device as well. Does it use VOLTE on his phone?
Also look at IMS registration in the phone and see if it's registered.

nxb said:
Could also be how his sim is set up. Volte has to be enabled there and in the phone. My suggestion would be to force LTE only on the device as well. Does it use VOLTE on his phone?
Also look at IMS registration in the phone and see if it's registered.
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Click to collapse
The person I borrowed the T-Mobile SIM from uses an iPhone on iOS 13. According to him, the option for turning on/off VoLTE from the settings is gone. He used to be able to turn it on and off at will; not anymore after iOS 13. It should be enabled by default on an iPhone though, I don't see why it would be off. It's almost a necessity on an iPhone I would think.
The LG V20 seems to be more limited in that sense, as on my previous Samsung phone I could enable 2G, 4G, LTE, etc, individually to force only one. I don't see any of those settings on my H910. I don't see any IMS info either.
Either way, I doubt T-Mobile would bother servicing my AT&T branded H910 phone in case IMS needed to be registered; in the case that it wasn't already. I've had really bad luck in the past dealing with T-Mobile on phones that are not T-Mobile branded.
Sent from my LG-H910 using Tapatalk

IMS has a phone component and a sim component.
you can check status in the service menu of IMS on the H910. Hope it works on my Tmo phone, getting my sim upgraded

nxb said:
IMS has a phone component and a sim component.
Hope it works on my Tmo phone, getting my sim upgraded
Click to expand...
Click to collapse
It should work if it's a T-Mobile phone. The H918 is 40% more expensive, so it would be great if the H910 worked with T-Mobile; however, it's not looking good.
Sent from my LG-H910 using Tapatalk

Eh, kinda. I'm having trouble too. My IMS services aren't connecting. Going to try a few different roms. I'm through an MVNO so still trying to get them to understand ISIM vs USIM.
see: https://www.quora.com/Are-4G-SIM-cards-of-two-types-VoLTE-and-LTE?share=1
https://www.slideshare.net/ikwe22/understanding-telecom-sim-and-usim-isim-for-lte

nxb said:
Eh, kinda. I'm having trouble too. My IMS services aren't connecting. Going to try a few different roms. I'm through an MVNO so still trying to get them to understand ISIM vs USIM.
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Gotcha, I hope it works. I was mentioning to @C D which has helped me understand a lot about VoLTE, that I'm starting to give in to the system of using whatever carrier my phone supports, as long as I can keep using my H910. The removable battery & IR blaster era has come to an end, and I don't think I need another phone right now other than the V20. I might even consider going back to the AT&T MVNO I was using before.
Sent from my LG-H910 using Tapatalk

Latest result: oreo works but not nougat.
IMS never registers. Maybe I can fix it. At least now OK sim-wise. Unfortunately doing the sim swap broke tethering.

Hi guys, I am sorry for reviving the old thread.
I too owned H990DS Sea version on latest nougat. It has volte option but just couldn't switch on.
Please take a look at this thread on LG G8
https://forum.xda-developers.com/t/...ther-qualcomm-powered-lg-devices-too.4343655/
I tried on my H990DS using the above thread's method and it didn't work. I was informed that the mbn files are for LG G8. We need mbn files that are specific for LG V20. I have searched up and down and I couldn't find any.
So I hope that I have provided some insights and I hope any member/master/guru out there can help where to find the mbn file (collection of all international carriers mbn) and make volte works for H990DS.

Can LS997 be forced to work on T mobile or other carriers?

I've got an old LS997 which was my daily driver a few years ago on Sprint. Not anymore and now our new plan is under T mobile. I flashed the LS997 version of /e/OS to it (a de-googled version of LineageOS) and it seems to work fine, except poor reception compared to my newer Pixel 4A (which has newer LTE and NR-NSA modem and maybe better SNR? not sure...)
Importantly, call and SMS do not work. It would be cool if these could be made to work so this phone could be used as a backup. T-mobile does not give their blessing, they claim it is not supported. Why is it so? LTE is GSM technology, and LTE data works as well as it did when it was sprint years ago, shouldn't SMS and calling work over VoLTE? and hell if T mobile adopted Sprint's network, they should have kept support for CDMA in addition to GSM phones to maximize the number of supported devices and minimize barriers to Sprint customers when said customers transition over from team yellow to magenta.
I played with the following settings:
* configuring the APN as per the official guide.
* tried a few random selections under "preferred network type" currently have the most inclusive option selected. (NR/LTE/TDSCDMA/CDMA/EvDo/GSM/WCDMA
* CDMA Subscription selection, tried both RUIM/SIM and NV
I suspect it simply will not work because it is in fact an LS997, and does not support the bands and technology the T-Mobile network uses. Since they are GSM and Sprint was CDMA, and my vague non-technical understanding is that Sprint used some bodgy CMDA bull**** for voice and SMS and GSM technology for data. though that would explain why mobile network state is disconnected and mobile voice network type is unknown, while mobile data network type is LTE and works fine.
Dumb question, what would happen if I were to do the forbidden thing: flash US996 bootloader and ROM to this device? or deliberately overwrite the radio.img? Something about there not being KYZ files for the LS997 variant means no going back but hey Sprint doesn't exist anymore so who cares. Worst case my almost useless phone would be bricked, though I do sometimes use it on the side as a sort of tablet and to record videos so it would be ashame to completely destroy it, but seeing the phone can be had well under $100... meh.
Is it possible to do this acknologing there is probably no turning back and also there is a good chance of hard bricking?