How to enable VoLTE (Voice over LTE)?

Fortsetzung der Diskussion von Enable HD Voice on the Fairphone 1?:

I did not found the option: Settings > Cellular network settings > Enhanced 4G LTE Mode.

Thanks for help.

In the thread you mention it says that it is not possible.
I guess that’s the reason you can’t find the option.


Just found this thread while searching for VoLTE. The old thread was for FP1 (no LTE) at all. The FP2 HW is capable of using VoLTE, AFAIK. The question is what is missing. I heard that the net provider needs activity activate it for a given smartphone. Is this true?


I wan’t to get back on the discussion about VoLTE on FP2.
As the phone is capable of LTE there is no reason to not support VoLTE.
The NetProvider has to enable it, but what is the possition of Fairphone to this topic?


Does anyone know if the Fairphone 2 supports VoLTE?
(sorry for necro-bumping an old thread, not sure if that’s frowned upon here)

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When I was looking for Wifi calling, at least in LineageOS I saw status info and a switch for this in the Android Test menu (dial *#*#4636#*#*).
Don’t know about the Fairphone OSes.

Sorry, can’t find that info with FPOS; and I guess, that counts for FPOOS as well.

In FPOOS I can see the following buttons in the test menu:

  • turn on IMS registration required
  • turn off VOLTE provisioned flag

However, I’m not sure if that’s sufficient for VoLTE support.

The normal FP OS 17.09.3 has those options as well. It looks like IMS would need to be enabled to use VoLTE, but whether that is sufficient, I do not know.
(My operator does not appear to offer VoLTE yet, so I cannot test it)

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For the cross reference: I created a feature request for VoLTE support at the FP2-LineageOS community bugtracker:

Summary: My tariff / SIM does support VoLTE, but I’m unable to enable it on Lineage 14.1.


Well, it would be interesting if VoLTE was possible without network operator cooperation. I know that my company has worked together with the OS hardware vendors do implement a solution which harmonizes with the network. And I got the impression that every operator has its own VoLTE implemenation and thus the implementations differ per network. Maybe it is possible if we can tune the required parameters, only Fairphone would need to know which are the parameters to adjust…

I’m not sure if other people have reported on this already, but I can confirm that during a stay in the US in September my FP2 (running Fairphone OS at that time) offered me the VoLTE option for the T-Mobile US SIM card that I was using in the second slot (4G during the stay) alongside my German SIM card in the first slot.


I’m wondering where in the US you were, since 4G on a Fairphone isn’t supposed to work on US networks. And how did this offer look like?

@Amber It appears to me network operators are hesitant to enable it because they don’t want to break phonecalls and thus test it with many hardware vendors before enabling.

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Hi Albert,

indeed, and it happens even with tested phones with just tiny adjustments in the network from which is unexpected to have influence on it. As a result you may e.g. be unable to receive calls. I know it :wink:

Regards, Alexander.

I noticed some strange behaviour with VoLTE as well. I bought a (Germany) prepaid card which gave me the option to use VoLTE in the Cellular Network Settings. Then, I chose to get an actual contract with Now, however, the option is not there anymore in the Cellular Network Settings even though I activated the option in the customer service pages at I’ll need to do some digging with those guys to get it running and maybe also activate WiFi Calling :slight_smile:


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Hi all,
I recently read that Telefonica in Germany has opened VoLTE and VoWiFi for all customers in their network. Since I guess that quite some people use their network with their Fairphone 2, we now should have enough people to get a clear picture of what is possible and what not on terms of VoLTE.
I still don’t have any such settings available in the normal settings menu, the Android menu just tells me I could disable the VoLTE flag and I could deactivate the IMS registration. When calling while having LTE available it still falls back to a different technology (CSFB).
So in general it looks like it is capable of doing VoLTE, in particular it isn’t. For VoWiFi I don’t have any hope since that was destroyed in the earlier thread which is already closed (otherwise I would have posted there).
Any more ideas on VoLTE?


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I opened it again.

Latest WiFi calling (currently non-)developments are here …

… and some background here …


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