Terracube 2e - Only 3G for calls?

Hi all
I purchased Terracube 2e (Murena) last May and I am basically very very happy with it. However call quality is deteriorating, calls are distorted and sometimes drop out completely.

I called EE to discuss. They spent a lot of time on the problem and eventually said that although Data is going by 4G calls from / to my phone are 3G only.

Going into settings the phone gives the option of VoLPE, but the button greys out when a call is made or received.

Did I buy an obsolete 3G phone or is there something I can do?

Thanks in advance

I used the Teracube 2e (emerald) for a year: bought from Teracube last year with stock software; installed /e/OS Android R (Android 11) myself & never upgraded. VoLTE settings were never visible from the relevant Settings page and mobile calls cut off mobile data every single time.

Recently I installed /e/OS Android T (Android 13) on a OnePlus series phone and VoLTE looks abundantly supported (I can’t be sure since haven’t returned yet to my carrier country).

Therefore my best hope for “something to do” would be to install Android S (12) immediately, and then T if & when it comes out for the Teracube platform.

Thank you for your reply.

If I want to change the operating system as you describe can I do that from the phone or do I need to load it from a PC? I already feel out of my depth…



you can’t do it from the phone, and the automatic installation procedure (“Easy-Installer”) doesn’t do version upgrades (yet). So you’d have to follow the “Command line” instructions on this page, which does require a PC connection: https://doc.e.foundation/devices/emerald

Also check your serial number to be sure your device matches… there’s another one of these device pages for the older Teracube 2e in case that’s the one you have.

Hi Robert
I think I am out of my depth here.
I am not sure where to go with this. Slightly miffed I have a redundant phone already. It isn’t 18 months old yet…

Perhaps you could tell us exactly the version on your phone using [HOWTO] Give complete /e/OS version info easily for support, answers, comparison etc, in case anyone can help narrow down your options.

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Hi Iain
Version is: 1.16-s-20231017342507-stable-emerald

Many thanks

Hi Paul,

So it seems you are fully up to date.

This is a list of the issues tagged emarald at Gitlab. Personal opinion (no experience of the device) one might say that this has been something of a difficult situation for a while, as not all users seem to report exactly the same thing.

Maybe this VoWiFi not working on Teracube Emerald – #5417 is close to your situation? However there are similar issues; https://gitlab.e.foundation/e/backlog/-/issues/6391 and https://gitlab.e.foundation/e/backlog/-/issues/7217. It might be a good idea to try to fine tune your observations to add to the most suitable link.

To add to an issue please read Report an isssue

Alternatively, as a Murena purchased phone you might consider the “Contact us” Support form: https://murena.com/contact-us/.

The form is mentioned in Week 45, Development and Testing Updates under a sub-heading at the foot of the page. /e/OS website and social media Links and Support.

Looks like Android 13 (T) for the Teracube (both variants) has been on the way: https://community.myteracube.com/t/beta-2-android-13-for-teracube-2e/4731

What works … 2. VoLTE, Vowifi, wifi, and Bluetooth have all been tested

I would think that a working (i.e. out of Beta) stock Android 13 on Teracube would mean /e/OS can then link to it from the source tree and release T builds shortly afterward.

In advance of the upgrade, to @aibd & others: is a reversion from Android 11 (R) /e/OS to stock recommended to OTA update the Teracube firmware to whatever firmware accompanies Android 12 or 13? Or would sideloading the new /e/OS ZIP be sufficient? I ask since there aren’t the usual warnings in the installation document about the Android versions matching.

As the stable build is capable of OTA version upgrade from Android 11 (R) to Android 12 (S) according to OS OTA upgrades I would assume that any required vendor blobs must be present in the stable OTA upgrade, and thus in the ROM itself.

If I had the device with /e/OS R dev installed, I would firstly consider downloading the dev and stable Android 12 (S) ROMs and see with a payload dumper how different the ROMs were. Specifically looking for evidence of vendor partitions or upgrade firmware.

I guess I would also consider the risks of changing dev to stable at my current Android R (after I had done a full backup and reduced my installed apps to essential).

I answered a different question with similar issues here: [Walkthrough] Extract eRecovery and boot images using payload-dumper-go - #3 by mihi. Perhaps the reply was both over cautious while not too discouraging (??) – as it happened there was a happy outcome reported in the end.

The requirement for experimentation is courage and a transferable backup of essentials.

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I would like to thank you and other respondents for your input.

This phone was sold as being fit for the general public, no mention is made of requiring specialist knowledge. Your answers are very comprehensive but mean virtually nothing to me and are not something I can implement. My skills do not lie in this area.

The position now is that I have the latest upgrade (that I am offered through ‘Updater’ on phone) which is /e/OS 1.16-s-20231017342507-stable-emerald.

When I go to ‘Network & Internet’ and tap on ‘Calls & SMS’ I find ‘Calls - EE’ & ‘SMS - EE’ are greyed out and can’t be clicked on.

Finally I have noticed that the WiFi icon at top of screen is sometimes replaced by ‘LTE’ for a while now and again.

Presumably this is beyond the skill set of a regular phone shop / phone repairer?

Thank you again for your help.


Hi Paul,

First I sincerely apologise that Post #10 is understandably not at “general public” level.

As a synopsis of my Post #8 to you, I do think the teracube has some “issues” which may require special help from the devs or even changes to the software. (Aside, there is some evidence that some advancement in the software is in progress.)

This is my reason for pointing you towards the Gitlab issues, and the Contact us method to get help.

As a Customer this, I think, is the route you should take now.

I watched my status bar a bit … I see LTE, H, or H+ frequently when out and about, but very much less so indoors with WiFi connection.

I always associate this with the quality of my mobile (data) connection. Whether it replaces the WiFi notification, I am less certain.

This nearest I can assume is that I am not given the LTE notifier at home with good WiFi, but see it mostly in urban (good coverage) situations. (What I report would maybe fit with me living in an LTE dead spot, except that does not fit with SIM status, below, which tells me LTE is the Mobile voice + data network type)

You might consider collecting some data on from Settings > About phone > SIM status to help you decide whether you have a phone or a carrier issue.

You might try to collect a chart of Signal strength | Mobile voice + data network type that you find at home and frequently used locations.

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FYI @Paul-in-England - https://community.myteracube.com/t/vowifi-wifi-calling-on-e-now-working-on-v-1-17s-a12/4869

Here’s a grisly report of the Android 13 stock Beta not working yet on the Teracube 2e :grimacing: (edit: Android 13 beta problem reported here might’ve been caused by bad hardware) https://community.myteracube.com/t/beta-2-android-13-for-teracube-2e/4731/74

I have had to replace the Terracube phone with a Nokia on contract - awful, everything is Google…

My Terracube will not connect on first call of the day - the person I call cannot hear me, I can hear them. I have to redial - not a good look in business environment.
Texts don’t send but no error message 'text not sent or similar).

Ability to connect to local mast very poor.

Running latest update - 1.18-s-20231207360611-stable-emerald. Not very stable in my opinion.

I have been in contact with Murena.com helpdesk but they haven’t responded recently, I sent some screenshots as they requested. Should I throw in the towel and ask for a refund (four year warranty - would that be valid in this case?) or replacement with something fully functional - I wouldn’t mind a used phone but as a matter of principle I am not funding a brand new phone from an organisation that doesn’t support their product.

I am disappointed. The idea behind de-googled phones is sound but the execution in this case is lacking. Does anyone have any guidance on what a non-techie, privacy minded person might do next?

Thank you all for your help and patience.
Kind regards

Hi all.
I am still in limbo with this awful phone.

I have two questions for those of you familiar with these phones and with Murena:

  1. Is there anyone out there using a Terracube 2e with /e/ OS and making phone calls? I am in UK using EE.

  2. Do you find Murena to be a reputable business? I have had no luck establishing a workable relationship with their support dept. I can’t get a helpful conversation with anyone. I have offered to take any working phone they have - new or used if it actually makes phone calls but no helpful response.

Phone spec:
OS is 1.21 1-s-20240326 389527 - stable - emerald

Build No:
e-emerald-user 12 sq3a.220705.004 eng.root.2024 03 26.005 121 dev-keys

I’ve used my 2e emerald on Android 11 /e/OS regularly for calling in India. There was no trouble except its utter failure to maintain an Internet connection while on a call, ringing in, or ringing out… an obvious VoLTE problem as reported above already since the local carrier supports VoLTE well.

From the Android 13 support for VoLTE on my current phone, I would bet my new phone that the (hopefully soon) coming Android 13 for the Teracube would fix all the calling issues on my old phone.

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