Brussels / 3 & 4 February 2024



Marius has been playing around with VoLTE with Qualcomm Mediatek devices. He has got to the point of being able to make and receive calls and send and receive SMSs on Ubuntu Touch ported devices. It is still very hacky. Without any knowledge of the modem stack it seemed impossibly difficult, but now we are getting some insights into how it works it is possible to see how the binary blobs are doing stuff. The way forward was to run Android and capture all the calls made to the drivers. Sailfish have some of it working, so their solution provided tools too.

The fixes so far are very specific, every proprietary system has its own unique way of doing things. It is a horrible standard, and no carrier even follows the standard. The modem is a black box with no outputs. To be honest, when it works, we don’t know why it works. It works perfectly well, though, so result. He would like to share his results, to discuss with the wider community how we can roll this out to get more devices supported.

In the recent and coming years 2G and 3G are being phased out by network operators, especially on a lot of Mobile Foss OSes that are Halium based. This means that they will be useless because you can't make calls any more. It has been extremely difficult to enable VoLTE service due to all the proprietary components.

VoLTE stands for Voice over LTE, and LTE (Long Term Evolution) is better known as 4G. So essentially, VoLTE amounts to mobile calls over a 4G network.


Marius Gripsgard