Do any android dual LTE phones support VOWiFi on one SIM using data from the other

Jzl

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There has been some discussion about using VOWiFi to avoid roaming costs when travelling abroad. There is also confirmation that using some iPhones will allow you to use the second SIM data as the "WiFi" connection. https://mybroadband.co.za/forum/thr...-vowifi-while-overseas.1064050/#post-24723718

Does anyone know if this is possible on one of the dual LTE android phones? E.g. Can I use my S.A. Vodacom/ Telkom etc SIM on VOxx using the data from the second SIM which may be O2 while I'm in Germany.

Background: VOWiFi allows you WiFi connection to work as a virtual base station on you home network. Calls are billed as if originating from you home network i.e. local calls.

Any help appreciated, I'm struggling to find answers.
 

Speedster

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There has been some discussion about using VOWiFi to avoid roaming costs when travelling abroad. There is also confirmation that using some iPhones will allow you to use the second SIM data as the "WiFi" connection. https://mybroadband.co.za/forum/thr...-vowifi-while-overseas.1064050/#post-24723718

Does anyone know if this is possible on one of the dual LTE android phones? E.g. Can I use my S.A. Vodacom/ Telkom etc SIM on VOxx using the data from the second SIM which may be O2 while I'm in Germany.

Background: VOWiFi allows you WiFi connection to work as a virtual base station on you home network. Calls are billed as if originating from you home network i.e. local calls.

Any help appreciated, I'm struggling to find answers.
A relatively easy solution would be to pop a local sim card in one of those portable WiFi routers
 

Jzl

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A relatively easy solution would be to pop a local sim card in one of those portable WiFi routers
Yes, thanks or a second phone as hotspot. I'm trying to avoid that. I have a local SIM in Germany and here. I want to keep presence in both countries and a dual SIM would be first prize!!
 

Speedster

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Yes, thanks or a second phone as hotspot. I'm trying to avoid that. I have a local SIM in Germany and here. I want to keep presence in both countries and a dual SIM would be first prize!!
That would be fantastic yes. I will be traveling internationally quite a bit this year, so I'm interested in this too. My P30 lite allows for VoLTE and VoWiFi. Quality on VoWifi is so poor I've disabled it, although I'm hoping to give it a go when traveling.

I don't think I'm able to use my second sim as the data though.
 
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Ecco

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I have a Samsung note 10. If it helps look at the attached pic.

Both Sims are showing VoLTE. Sim1 is MTN for voice and Data. Sim2 I use for voice only and is on Vodacom. Regarding VoWifi I suspect it should be the same. Can't say for sure but hope this helps you get some idea of how the Sims work.

Screenshot_20200118-094250_Chrome.jpg
 

Speedster

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I have a Samsung note 10. If it helps look at the attached pic.

Both Sims are showing VoLTE. Sim1 is MTN for voice and Data. Sim2 I use for voice only and is on Vodacom. Regarding VoWifi I suspect it should be the same. Can't say for sure but hope this helps you get some idea of how the Sims work.

View attachment 769724
I think he's asking if you can use the data connection on SIM2 to access VoWifi on SIM1.
 

Jzl

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Thanks for the replies. Some of the older/ cheaper dial SIMs only allow one SIM that can be selected for data. So for example the my wife has the Huawei p20 lite. VOLTE and VOWiFi can only be selected on the data SIM. When I select my German SIMfor data/VOWiFi and am on Wi-Fi (in S.A.) I get local call rates in Germany. Unfortunately no local data as the other SIM is 2G only, no data. Selecting VOLTE on the German SIM would be roaming rates. By the way great quality on German calls from day WiFi (Telkom 4G modem)and can receive and make calls!

Newer phones allow data selection on both SIMs. @Speedster is right, I am really interested in VO2ndSIMdata. It's confirmed to work on iPhone. I would love to get confirmation that it works on android. Getting access to a test phone is a problem short of buying one.

@Ecco I believe your S10 would probably be able to do VO2ndSIMdata. It may be difficult to be sure it is working with two local SIMs. Here's what I would do for my purposes.

Setup
SIM 1 (local): select data and select normal calling (not Volte)
SIM2 (foreign): Select VOWiFi, deselect VOLTE, deselect data roaming.
Switch off WiFi
Test: make a VOWiFi call using SIM2 to a German number using.
Checks: if successful check balances on the German SIM to make sure it went through as a local call.

Thanks for the help so far.
 

deweyzeph

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It's not called "voice over wifi" for nothing. It only works over wifi. The data connection on your second sim is not a wifi connection.
 

Jzl

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@deweyzeph thanks, sadly that may be how android sees it too. IPhone does however seem to get around this semantic limitation. Refer reference in earlier post.
 

Sayf777

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It's not called "voice over wifi" for nothing. It only works over wifi. The data connection on your second sim is not a wifi connection.
Vowifi does become active from hotspot connections from a phone. So if an android phone allows this, it should work.
 

deweyzeph

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Vowifi does become active from hotspot connections from a phone. So if an android phone allows this, it should work.
A phone can't connect to its own wifi hotspot. When you enable a wifi hotspot on your phone, the wifi client is disabled, so a phone can't connect to itself. The wifi radio in your phone can either act as an access point or a client, but it can't do both.
 

Jzl

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Thanks @deweyzeph and @Sayf777 what I am looking for is VO2ndSIMdata for lack of a better description. It uses the VOWiFi type functionality of the one SIM but uses the data from the second SIM rather than actual WiFi.

So yes while you are absolutely correct you can't connect to your own phones WiFi, you should be able to connect to data from the other SIM, at least theoretically. It has been confirmed on this forum that this is not just theory by is practically realised on the dual sim iPhone 11!!!

So my question is not if VO2ndSIMdata is possible, but if it is possible on any Android devices.


My understanding is that you would need a Dual SIM Dual Active (DSDA) device with two signal processors. Dual SIM Dual Standby (DSDS) may also be possible depending on where the VOxx processing takes place. The main thing is that data is available on one SIM while making a call via the other.
 
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